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CR

CR – Cryospheric Sciences

DM4
Convener: Olaf Eisen
Thu, 07 May, 12:45–13:45

CR1 – The State of the Cryosphere: Past, Present, Future

CR1.1

This session explores improvements in our understanding and quantification of past, present and future ice sheet and sea-level changes. We invite contributions about the following topics:

How to improve the reliability of the projections using observations (paleo and present), models and model intercomparison exercises (ISMIP6, and others); assessment of uncertainties and probability distributions of the ice sheets' contribution to sea level change; emerging processes; feedbacks coming from interactions between components (ice sheets, ocean, atmosphere, solid earth). We focus on the present and future (multi-centennial) Greenland and Antarctic ice sheets, but paleo-studies are encouraged if they shed a light on the mentioned topics.

This session is related to both ISMASS (http://www.climate-cryosphere.org/activities/groups/ismass) and ISMIP6 (http://www.climate-cryosphere.org/activities/targeted/ismip6).

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Co-organized by CL4/OS1, co-sponsored by CliC
Convener: Frank Pattyn | Co-conveners: Konstanze HaubnerECSECS, Guðfinna Aðalgeirsdóttir, Helene Seroussi, Donald SlaterECSECS
Displays
| Chat Thu, 07 May, 14:00–15:45
CR1.2

The largest single source of uncertainty in projections of future global sea level is associated with the mass balance of the Antarctic Ice Sheet (AIS). In the short-term, it cannot be stated with certainty whether the mass balance of the AIS is positive or negative; in the long-term, the possibility exists that melting of the coastal shelves around Antarctica will lead to an irreversible commitment to ongoing sea level rise. Observational and paleoclimate studies can help to reduce this uncertainty, constraining the parameterizations of physical processes within ice sheet models and allowing for improved projections of future global sea level rise. This session welcomes presentations covering all aspects of observation, paleoclimate reconstruction and modeling of the AIS. Presentations that focus on the mass balance of the AIS and its contribution towards changes in global sea level are particularly encouraged.

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Co-organized by CL4/G3/OS1
Convener: Steven Phipps | Co-conveners: Florence Colleoni, Chris Fogwill, Taryn Noble
Displays
| Chat Tue, 05 May, 10:45–12:30
CR1.3

Fifty years of routine in-situ and satellite observations have revealed the progressive deterioration of Antarctica’s most vulnerable regions to climate change: the Antarctic Peninsula and West Antarctic ice sheets. The rapid destabilisation of Larsen A and B ice shelves in the Antarctic Peninsula and the ongoing, potentially irreversible ice losses at Pine Island and Thwaites glaciers, West Antarctica, have been linked to a complex marriage of ocean and atmosphere forcing mechanisms impinging on the continent from the Weddell, Bellingshausen and Amundsen Seas. These phenomena have raised questions about the past and future stability of the ice sheets and water mass properties, and have motivated research focused on elucidating the precise ice-ocean-atmosphere interactions controlling oceanographic and cryospheric change over palaeo- to contemporary timescales. Offshore, similar questions have arisen regarding the role of seabed topography and changing sea ice and oceanographic conditions, and how such phenomena may ultimately impact ice sheet mass-losses.

This session welcomes contributions examining the range of controls driving cryospheric and oceanic change across the Antarctic Peninsula and West Antarctic Ice Sheet regions, as well as those in the wider Weddell Sea sector. Together with model and remotely sensed studies, this session will showcase early results from the International Thwaites Glacier Collaboration and several recent research campaigns conducted in the Weddell Sea.

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Co-organized by CL4/OS1
Convener: Christine BatchelorECSECS | Co-conveners: Kiya RivermanECSECS, Frazer ChristieECSECS, Katherine HutchinsonECSECS, David Vaughan
Displays
| Chat Wed, 06 May, 14:00–15:45
CR1.5

Rationale: Progressive thawing of permafrost poses a significant threat to the stability of arctic landscapes, and has strong consequences for our climate. To predict the transition of arctic landscapes and its consequence for climate-feedback, we need to understand the dynamics of permafrost thaw. Most climate models assume a gradual, top-down thawing of permafrost, resulting in gradual decomposition of carbon and enhanced plant growth (“Arctic Greening”). However, evidence of an alternative, abrupt thawing trajectory of permafrost (“Arctic Browning”) is currently increasing across the Arctic. Consequences for landscape stability and climate feedback diverge widely between these trajectories, which emphasizes the need to understand their triggers.

Aim: In this session we aim to bring together and integrate the state-of the art on the future development of permafrost ecosystems from various disciplinary backgrounds. Thereby, we hope to improve our understanding of (i) the anticipated occurrence of various thaw phenomena under global warming, (ii) the implications of these various thaw phenomena for permafrost ecosystems and (iii) the implications of various thaw phenomena for climate feedbacks.

We have compiled an exiting programme covering mechanisms, processes and fluxes at different spatial scales, from landscape to microbe. Contributions come from accross all permafrost regions from a wide range of research institutes.

The session will be started of by professor Merritt Turetsky (incoming Director, INSTAAR at the University of Colorado Boulder) on our current knowledge and the main research gaps related to the cross-scale impacts of abrupt thaw phenomena, from local-scale changes that affect water and food security to carbon emissions and global climate. She will also discuss how permafrost thaw is interacting with other disturbance regimes such as wildfire.

Public information:
Progressive thawing of permafrost poses a significant threat to the stability of arctic landscapes, and has strong consequences for our climate. To predict the transition of arctic landscapes and its consequence for climate-feedback, we need to understand the dynamics of permafrost thaw. Our programme brings together the state-of the art on permafrost ecosystems from various disciplinary backgrounds. Thereby, we hope to improve our understanding of (i) the anticipated occurrence of various thaw phenomena under global warming, (ii) the implications for permafrost ecosystems and (iii) climate feedbacks

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Co-organized by BG1
Convener: Juul Limpens | Co-conveners: Rúna MagnússonECSECS, Gabriela Schaepman-Strub
Displays
| Chat Tue, 05 May, 16:15–18:00

CR2 – Instrumental and paleo-archive observations and analysis of the cryosphere

CR2.1

Geophysical measurements offer important baseline datasets as well as validation for modelling and remote sensing products for cryospheric sciences. Applications include the dynamics of ice-sheets, alpine glaciers and sea ice, changes in snow cover properties of seasonal and permanent snow, snow/ice-atmosphere-ocean interactions, permafrost degradation, geomorphic processes and changes in subsurface materials.

In this session we welcome contributions related to a wide spectrum of geophysical- and in-situ methods, including advances in diverse techniques such as radioglaciology, active and passive seismology, acoustic sounding, GPS/GNSS reflectometry or time delay techniques, cosmic ray neutron sensing, drone applications, geoelectrics and NMR. Contributions may concern field applications as well as new approaches in geophysical/in-situ survey techniques or theoretical advances in the field of data analysis, processing or inversion. Case studies from all parts of the cryosphere such as snow, alpine glaciers, ice sheets, glacial and periglacial environments and sea ice are highly welcome. The focus of the session is to compare experiences in the application, processing, analysis and interpretation of different geophysical and in-situ techniques in these highly complex environments.

This session is offered as a PICO: an engaging presentation format that has been successfully tested for this session during the last three years at EGU. All selected contributions will present their research orally, and then further present their research using interactive screens. This results in rich scientific feedback and is an effective tool for communicating science with high visibility.

This is a joined session - we merged with the former session SM5.5 'Active and passive seismic methods for imaging and monitoring the cryosphere'.


++++++++++++++++++++++++++++ Invited Speaker ++++++++++++++++++++++++++++++++++++

Dustin Schroeder: Observing Evolving Subglacial Conditions with Muti-Temporal Radar Sounding

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Co-organized by HS1.1/SM4
Convener: Franziska KochECSECS | Co-conveners: Nanna Bjørnholt Karlsson, Kristina Keating, Mariusz Majdanski, Emma C. SmithECSECS, Schlindwein Vera, Andreas Köhler
Displays
| Chat Mon, 04 May, 08:30–10:15
CR2.2

Studies of ice extent, volume and dynamics during former glaciations are important for understanding past climates and evolution of the Earth’s surface, and also provide analogies for present-day ice sheets and their subglacial environments. This includes observations of glacial erosion, glacial transport and deposition of sediments, formation of fjords and their relation to ice streams, evidence for migration of ice divides, former locations of subglacial lakes, relations between high geothermal heat flow, basal ice melt and rapid ice flow, and other aspects of paleo glacier extent and behaviour. This session will bring together the interdisciplinary scientific community working on former ice covers from the perspectives of glacial geomorphology, quaternary geology, and numerical modeling. It will provide a forum in which field-based reconstructions and model-based simulations can be compared and contrasted. We particularly welcome contributions that shed light on ancient and more recent glaciations on Earth and their interaction with other components of the Earth System.

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Co-organized by GM7
Convener: Andy EmeryECSECS | Co-conveners: Eef van DongenECSECS, Jorge BernalesECSECS, Elisa MantelliECSECS, April DaltonECSECS, Samuel E. KelleyECSECS, Tom JordanECSECS, Kelly Hogan
Displays
| Chat Tue, 05 May, 14:00–18:00
CR2.4

The explosion of data and computing power that is now available to glaciologists presents significant opportunities for advancing our understanding of glacial environments. However, significant barriers exist to achieving this, with the scales and rates at which data are being generated rendering many traditional approaches to analysis impractical.
Researchers across nearly all fields of glaciology are therefore increasingly requiring the development of automated and/or machine learning based approaches to effectively monitor and investigate these environments, in addition to new ways of visualising results. This session will therefore bring together glaciologists who use big data, machine learning and/or artificial intelligence to help share knowledge of different approaches that are currently being taken by the community and where possible demonstrate their potential transferability in this emergent field. Contributions are invited from those involved in developing and/or applying methods that seek to address these data generation, analytical and visualisation challenges with the aim of gaining greater understanding of past, present and future glacier and ice sheet change.

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Convener: James LeaECSECS | Co-conveners: Celia A. BaumhoerECSECS, Stephen BroughECSECS, Soroush REZVANBEHBAHANIECSECS, Leigh Stearns
Displays
| Chat Wed, 06 May, 10:45–12:30
CR2.6

This session will focus on recent and upcoming advances in satellite remote sensing of the global cryosphere. We welcome presentations providing new insights into cryospheric processes in the broadest sense, ranging from ice sheets, glaciers, snow cover and snow properties, frozen soil and sea ice to extraterrestrial glaciology. While the advent of remote sensing has revolutionized the field of glaciology, a vast reservoir of potential remains to be unlocked by using these observations in concert with other data sets. We particularly encourage presentations discussing multi-platform data merging, integration of GIS and ground validation data, integration of remote sensing data into earth system models, as well as cloud computing and processing of super large data sets. We also encourage contributions focusing on historic satellite data re-analysis, novel processing approaches for upcoming satellite missions, and presentations outlining pathways to next-generation satellite missions for the coming decades.
We are committed to a well-balanced session and would like to highlight the session on twitter.

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Including CR Division Outstanding ECS Lecture
Convener: Rachel TillingECSECS | Co-conveners: Sophie BergerECSECS, Bert Wouters, Bas Altena, Amandine GUILLOT
Displays
| Chat Thu, 07 May, 08:30–12:30
CR2.7

Process understanding is key to assessing the sensitivity of glacier systems to changing climate. Comprehensive glacier monitoring provides the base for large-scale assessment of glacier change. Glaciers are monitored on different spatio-temporal scales, from extensive seasonal mass balance studies at selected glaciers to multi-decadal repeat inventories at the scale of entire mountain ranges. Internationally coordinated glacier monitoring aims at combining in-situ measurement with remotely sensed data, and local process understanding with global coverage. This session invites studies from a variety of disciplines, from tropical to polar glaciers, addressing both in-situ and remotely sensed monitoring of glaciers, as well as uncertainty assessments.

This year we have combined session CR2.7 with CR1.6 "Glaciers and ice caps under climate change":
Mountain glaciers and ice caps are major contributors to sea-level rise and have large impacts on water balance of local basins. This is a general session on glaciers and ice caps where the relationship to climate forms a particular focus. The IPCC AR5 of Working Group 1 covers Earths Glaciers and Ice Caps outside the ice sheets under the heading of Glaciers and shows that, despite much progress recently provided by the community, we are still left with substantial unknowns. We need to acquire more data, both from new fieldwork and release of unpublished data from prior years on mass changes of glaciers and ice caps from all regions of the world. We need to improve the understanding of the processes behind the changes, and we need to improve the application of models of different complexity. We welcome presentations on all aspects of mass changes; current, past and future changes based on field observations, remote sensing and modeling. Studies of physical processes controlling accumulation and ablation including calving and submarine melting, are especially welcome.

Solicited speakers:
Joshua R. Leigh: 'Identifying and mapping very small mountain glaciers on coarse to high-resolution imagery'
Martin Hoelzle: 'Glacier monitoring, capacity building and related cryospheric research in Central Asia'

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Convener: Frank Paul | Co-conveners: Inés Dussaillant, Gwenn Flowers, Jon Ove Hagen, Nicholas Barrand, Matthias Huss, Georg Kaser, Harry ZekollariECSECS
Displays
| Chat Mon, 04 May, 14:00–18:00
GI3.4

Space-based measurements of the Earth System, including its atmosphere, oceans, land surface, cryosphere, biosphere, and interior, require extensive prelaunch and post launch calibration and validation activities to ensure scientific accuracy and fitness for purpose throughout the 
lifetime of satellite missions. This requirement stems from the need to demonstrate unambiguously that the space-based measurements, typically based on engineering measurements by the detectors (e.g. photons), are sensitive to and match up with the geophysical and/or biogeochemical quantity of interest at a broad range of measurement locations on Earth. Most geophysical parameters vary in time and space, and the retrieval algorithms used must be accurate under the full range of conditions. Calibration and validation need to be carried out over the lifetime of missions in order to assure that any long-term variation in observation can be definitely be tied to the evolution of the Earth system. Such activities are also critical in ensuring that measurements can be inter-compared and used seamlessly to create long-term multi-instrument//multi-platform data sets, , which enable large-scale international science investigations into topics with high societal or environmental importance such as determining the ice mass balance of Greenland, monitoring the evolution of sea ice and snow cover in the Arctic and improving our knowledge of the terrestrial carbon cycle through multi-sensor forest biomass mapping. . This session seeks presentations on the use of surface-based, airborne, and/or space-based observations to prepare and calibrate/validate space-based satellite missions measuring our Earth system. A particular but not exclusive focus will be on activities carried out jointly by NASA and ESA as part of their Joint Program Planning Group Subgroup on calibration and validation and field activities.

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Co-organized by AS5/CR2
Convener: Jack Kaye | Co-convener: Malcolm W. J. Davidson
Displays
| Chat Tue, 05 May, 14:00–15:45
G3.3

Satellite altimetry provides the possibility to observe key parts of the hydrosphere, namely the ocean, ice, and continental surface water from space. Since the launch of Topex/Poseidon in 1992 the applications of altimetry have expanded from the open oceans to coastal zones, inland water, land and sea ice. Today, seven missions are in orbit, providing dense and near-global observations of surface elevation and several other parameters. Satellite altimetry has become an integral part of the global observation of the Earth‘s system and changes therein.

In recent years, new satellite altimetry missions have been launched carrying new instruments and operating in new orbits; the CryoSat-2/Sentinel-3 missions equipped with a Delay/Doppler altimeter, the Saral AltiKa mission carrying the first Ka band altimeter, and the recently launched photon counting laser altimeter on-board NASAs ICESat-2.

Fully exploiting this unprecedented availability of observables will enable new applications and results but also require novel and adapted methods of data analysis.
Across the different applications for satellite altimetry, the data analysis and underlying methods are similar and a knowledge exchange between the disciplines will be fruitful.
In this multidisciplinary altimetry session, we therefore invite contributions which discuss new methodology and applications for satellite altimetry in the fields of geodesy, hydrology, cryosphere, oceanography, and climatology.
Topics of such studies could for example be (but not limited to): creation of robust and consistent time series across sensors, validation experiments, combination of radar and laser altimetry e. g. for remote sensing of snow, classification of waveforms, application of data in a geodetic orbit, retracking, or combination with other remote sensing data sets.

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Co-organized by CR2/HS6/OS4
Convener: Eva BoergensECSECS | Co-conveners: Stefan Hendricks, Karina Nielsen, Louise Sandberg Sørensen, Bernd UebbingECSECS
Displays
| Chat Wed, 06 May, 10:45–12:30
CL1.14

Ice cores are a key archive to study past climate variability. Various physico-chemical proxies provide key insights into past temperature, atmospheric composition, volcanic activity, and atmospheric circulation. Despite the large body of empirical information available, we still lack a detailed, process-based understanding of the creation of the archived climatic signal. This session aims, in light of the new "Beyond EPICA Oldest Ice" (BE-OI) ice-core project, at an in-depth discussion on the extent to which climatic signals are archived in the proxy signals, how the archival processes – from the atmosphere to the surface to post-depositional changes in the firn and ice and even further smoothing/diffusion in the lower most part of the ice column – themselves affect the recorded signal, and how to optimally recover the original signals from existing ice-core records. We welcome contributions that shed light on this chain of processes, including interpretation of various proxies from new, or existing, ice core records from Antarctica, Greenland or high mountainous areas; analyses of climate model, reanalysis and back trajectory data; novel application of statistical and spectral methods to proxy data; or new measurement techniques. Finally, we encourage discussion about the impact the individual processes have on the relationship between proxy and past climate variability across various temporal and spatial scales.

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Including Milutin Milankovic Medal Lecture
Co-organized by CR2
Convener: Mathieu CasadoECSECS | Co-conveners: Pete AkersECSECS, Marie G. P. CavitteECSECS, Thomas MünchECSECS
Displays
| Chat Tue, 05 May, 10:45–12:30
GI1.3

This session is a result of a merge between GI1.3 and GM2.3:

Recent advances in image collection and topographic measurements are providing unprecedented insight into landscape and process characterization across the geosciences. In parallel, the increasing availability of digitised historical images, going back to the late 1800s, together with advances in digital photogrammetry software, have provided new opportunities for assessing and reconstructing long-term surface evolution from local to landscape scale. Such data can extend high-resolution time series into the pre-satellite era and offer exciting potential for distinguishing anthropogenic from natural causes of environmental change. For both historic and contemporary scenarios, augmenting classic techniques with digital imagery and ‘structure from motion’ (SfM) processing has democratized data access and offers a new measurement paradigm to geoscientists.

Such data are now available over spatial scales from millimetres to kilometres, and over durations of single events to lasting time series (e.g. from sub-second to century-duration time-lapse), allowing evaluation of event magnitude and frequency interrelationships. Despite a large volume of historical images available for reprocessing with modern methods, their full potential has not yet been widely exploited and uncertainties remain on the optimal types of information that can be extracted. Substantial opportunities are likely to be exposed by exploring such data resources with machine and deep learning approaches.

The session welcomes submissions from a broad range of geoscience disciplines such as geomorphology, cryosphere, volcanology, hydrology, bio-geosciences, and geology. Our goal is to create a diverse and interdisciplinary session to explore the potential of 2D and 3D image and topographic datasets for reconstructing and interpreting environments and processes, past and present. We aim to exchange experiences of modern photogrammetric and topographic measurement and modelling technologies, along with their associated data processing tools, to highlight their potentials, limitations, and challenges in different environments.

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Co-organized by EOS9/CL2/CR2/GM2/HS13/NH6
Convener: Livia PiermatteiECSECS | Co-conveners: Penelope HowECSECS, Wilfried KarelECSECS, Anette EltnerECSECS, Andreas KaiserECSECS, Mike James, Mark SmithECSECS, Jack WilliamsECSECS
Displays
| Chat Fri, 08 May, 08:30–10:15

CR3 – Snow and ice: properties, processes, hazards

CR3.1

All components of the cryosphere are strongly impacted by climate change and have been undergoing significant changes over the past decades. Most visibly, glaciers are shrinking and thinning. Snow cover and duration is reduced, and permafrost, in both Arctic and alpine environments, is thawing. Changes in sea ice cover and characteristics have attracted widespread attention, and changes in ice sheets are monitored with care and concern. 
Risks associated with one or several of these cryosphere components have been present throughout history. However, with ongoing climate change, we expect changes in the magnitude and frequency of hazards with profound implications for risks. New or growing glacier lakes pose a threat to downstream communities through the potential for sudden drainage. Thawing permafrost can destabilize mountain slopes, and eventually result in large landslide or destructive rock and ice avalanches. An accelerated rate of permafrost degradation in low-land areas poses risk to existing and planned infrastructure and raises concerns about large-scale emission of greenhouse gases currently trapped in Arctic permafrost. Decreased summertime sea ice extent may produce both risks and opportunities in terms of large-scale climate feedbacks and alterations, coastal vulnerability, and new access to transport routes and natural resources. Eventually, rapid acceleration of outlet glacier ice discharge and collapse of ice sheets is of major concern for sea level change. 
This session invites contributions across all cryosphere components that address risks associated with observed or projected physical processes. Contributions considering more than one cryosphere component (e.g. glaciers and permafrost) are particularly encouraged. Contributions can consider hazards and risks related to changes in the past, present or future. Furthermore, contributions may consider one or several components of risks (i.e. natural hazards, exposure, vulnerability) as long as conceptual clarity is ensured.

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Convener: Christian Huggel | Co-conveners: Michael Krautblatter, Matthew WestobyECSECS
Displays
| Chat Tue, 05 May, 08:30–10:15
CR3.2

Snow cover characteristics (e.g. spatial distribution, surface and internal physical properties) are continuously evolving over a wide range of scales due to meteorological conditions, such as precipitation, wind and radiation.
Most processes occurring in the snow cover depend on the vertical and horizontal distribution of its physical properties, which are primarily controlled by the microstructure of snow (e.g. density, specific surface area). In turn, snow metamorphism changes the microstructure, leading to feedback loops that affect the snow cover on coarser scales. This can have far-reaching implications for a wide range of applications, including snow hydrology, weather forecasting, climate modelling, and avalanche hazard forecasting or remote sensing of snow. The characterization of snow thus demands synergetic investigations of the hierarchy of processes across the scales ranging from explicit microstructure-based studies to sub-grid parameterizations for unresolved processes in large-scale phenomena (e.g. albedo, drifting snow).

This session is therefore devoted to modelling and measuring snow processes across scales. The aim is to gather researchers from various disciplines to share their expertise on snow processes in seasonal and perennial snowpacks. We invite contributions ranging from “small” scales, as encountered in microstructure studies, over “intermediate” scales typically relevant for 1D snowpack models, up to “coarse” scales, that typically emerge for spatially distributed modelling over mountainous or polar snow- and ice-covered terrain. Specifically, we welcome contributions reporting results from field, laboratory and numerical studies of the physical and chemical evolution of snowpacks, statistical or dynamic downscaling methods of atmospheric driving data, assimilation of in-situ and remotely sensed observations, representation of sub-grid processes in coarse-scale models, and evaluation of model performance and associated uncertainties.

This session is closely linked to the session 'Snow and ice accumulation, melt, and runoff generation in catchment hydrology', which addresses monitoring and modelling of snow for hydrologic applications.

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Co-organized by AS4/CL2/HS2.1
Convener: Nora Helbig | Co-conveners: Neige CalonneECSECS, Richard L.H. Essery, Henning Loewe, Vincent Vionnet
Displays
| Chat Thu, 07 May, 14:00–15:45
CR3.3

This session is devoted to the dynamics of dense and powder snow avalanches and their accompanying transitional regimes. One focus is their interaction with, and impact on, vulnerable elements, such as buildings, protection dams, forests, and roads. We welcome novel experimental and computational contributions including, but not limited to the topics of avalanche dynamics and related processes, physical vulnerability of structures impacted by snow avalanches, avalanche hazard zoning and avalanche mitigation strategies. These include field, laboratory and numerical studies that rely on new methods and techniques (radars, drone, satellite, etc.) as well as practical case studies.

Furthermore, we solicit novel contributions from the area of granular flows, viscoplastic flows, density currents, turbulent flows, as well as contributions from other gravitational mass flows communities, which can improve our understanding and modeling of snow avalanche propagation and their interaction with natural or man-made structures.

While the main focus of this session is on snow avalanche dynamics from basic knowledge to mitigation strategies, it is closely linked to session CR3.4 entitled "Snow avalanche formation: from snow mechanics to avalanche detection" which addresses avalanche formation, detection and forecasting.

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Co-organized by NH3
Convener: Thierry Faug | Co-conveners: Jan-Thomas Fischer, Florence Naaim-Bouvet, Betty Sovilla
Displays
| Chat Fri, 08 May, 16:15–18:00
CR3.4

Snow avalanches range among the most prominent natural hazards which threaten mountain communities worldwide. Snow avalanche formation is a complex critical phenomenon which starts with a failure processes at the scale of snow crystals and ends with the release of a large volume of snow at a scale of up to several hundred meters. The practical application of avalanche formation is avalanche forecasting, requiring a thorough understanding of the physical and mechanical properties of snow as well as the influence of meteorological boundary conditions (e.g. precipitation, wind and radiation).

This session aims to improve our understanding of avalanche formation processes and to foster the application to avalanche forecasting. We therefore welcome contributions from novel field, laboratory and numerical studies on topics including, but not limited to, the mechanical properties of snow, snow cover simulations, snow instability assessment, meteorological driving factors including drifting and blowing snow, spatial variability, avalanche release mechanics, remote avalanche detection and avalanche forecasting. While the main focus of this session is on avalanche formation, detection and forecasting, it is closely linked to session ‘CR3. Snow avalanche dynamics: from basic physical knowledge to mitigation strategies’, which addresses avalanche dynamics, risk assessment and mitigation strategies.

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Co-organized by NH3
Convener: Johan Gaume | Co-conveners: Ingrid Reiweger, Alec van Herwijnen
Displays
| Chat Fri, 08 May, 14:00–15:45
HS2.1.2

By accumulating precipitation at high elevations, snow and ice change the hydrologic response of a watershed. Water stored in the snow pack and in glaciers thus represents an important component of the hydrological budget in many regions of the world and a sustainment to life during dry seasons. Predicted impacts of climate change in headwater catchments (including a shift from snow to rain, earlier snowmelt and a decrease in peak snow accumulation) will affect both water resources distribution and water uses at multiple scales, with potential implications for energy and food production.
Our knowledge about snow/ice accumulation and melt patterns is highly uncertain, because of both limited availability and inherently large spatial variability of hydrological and weather data in remote areas at high elevations. This translates into limited process understanding, especially in a warming climate. The objective of this session is to integrate specialists focusing on snow accumulation and melt within the context of catchment hydrology and snow as a source for glacier ice and melt, hence streamflow. The aim is to integrate and share knowledge and experiences about experimental research, remote sensing and modelling.
Contributions addressing the following topics are welcome:
- experimental research on snowmelt runoff processes and potential implementation in hydrological models;
- development of novel strategies for snowmelt runoff modelling in various (or changing) climatic and land-cover conditions;
- evaluation of remote-sensing (time-lapse imagery, laser scanners, radar, optical photography, thermal and hyperspectral technologies) or in-situ snow products (albedo, snow cover or depth, snow water equivalent) and application for snowmelt runoff calibration, data assimilation, streamflow forecasting or snow and ice physical properties quantification;
- observational and modelling studies that shed new light on hydrological processes in glacier-covered catchments, e.g., impacts of glacier retreat on water resources and water storage dynamic or the application of techniques for tracing water flow paths;
- studies on cryosphere-influenced mountain hydrology, such as landforms at high elevation and their relationship with streamflow, water balance of snow/ice-dominated, mountain regions.

This session is closely linked to session 'Modelling and measuring snow processes across scales', which addresses monitoring and modelling of snow processes across scales.

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Co-organized by CR3
Convener: Guillaume Thirel | Co-conveners: Francesco AvanziECSECS, Doris DuethmannECSECS, Abror Gafurov, Juraj Parajka, Rafael PimentelECSECS
Displays
| Chat Tue, 05 May, 08:30–12:30
AS2.10

Atmosphere and Cryosphere are closely linked and need to be investigated as an interdisciplinary subject. Most of the cryospheric areas have undergone severe changes in last decades while such areas have been more fragile and less adaptable to global climate changes. This AS-CR session invites model- and observational-based investigations on any aspects of linkages between atmospheric processes and snow and ice on local, regional and global scales. Emphasis is given on the Arctic, high latitudes and altitudes, mountains, sea ice, Antarctic regions. In particular, we encourage studies that address aerosols (such as Black Carbon, Organic Carbon, dust, volcanic ash, diatoms, bioaerosols, bacteria, etc.) and changes in the cryosphere, e.g., effects on snow/ice melt and albedo. The session also focus on dust transport, aeolian deposition, and volcanic dust, including health, environmental or climate impacts at high latitudes, high altitudes and cold Polar Regions. We include contributions on biological and ecological sciences including dust-organisms interactions, cryoconites, bio-albedo, eco-physiological, biogeochemical and genomic studies. Related topics are light absorbing impurities, cold deserts, dust storms, long-range transport, glaciers darkening, polar ecology, and more. The scientific understanding of the AS-CR interaction needs to be addressed better and linked to the global climate predictions scenarios.

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Co-organized by CL2/CR3
Convener: Pavla Dagsson WaldhauserovaECSECS | Co-conveners: Outi Meinander, Marie Dumont, Biagio Di MauroECSECS
Displays
| Chat Mon, 04 May, 10:45–12:30

CR4 – Frozen ground, debris-covered glaciers and geomorphology

CR4.1

Glacial landscapes are constantly transforming in response to past and present climate and environmental conditions, e.g. available debris. Especially due to past and present global warming, rapid changes in these landscapes are observed. These changes are associated with transitions from different processual states : glacial – periglacial – paraglacial, and associated morphologies and landforms, including debris- covered glaciers and rock glaciers which are less understood. To unravel and quantify these past and present evolutions, controls and feedbacks, a broad spectrum of methods are available, including geomorphological mapping, dating, remote sensing, geophysics, numerical modelling, climate reconstruction, field observations and more. This session welcomes contributions related to all these methods, concepts and approaches used to investigate glacial-periglacial-paraglacial landscape evolution, controls and feedbacks. We seek abstracts on topics such as:
• conceptual frameworks of the evolution of glaciated landscapes;
• processual studies of glacial, paraglacial and periglacial landscapes across all temporal and spatial scales;
• transitions of glacial to periglacial or paraglacial landforms, and the role of debris cover within these glacier land systems
• geomorphometry of past and presently glaciated landscapes, debris-covered glaciers and rock glaciers.
• Interaction between debris-covered glaciers and the wider land system, for example, in terms of geohazards, erosion, sediment transport, and deposition.

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Co-organized by GM7
Convener: Johannes BuckelECSECS | Co-conveners: Adina Racoviteanu, Evan MilesECSECS, Lindsey Nicholson, Tobias Bolch, Anne VoigtländerECSECS, Jasper Knight, Darren Jones
Displays
| Chat Wed, 06 May, 08:30–12:30
CR4.2

The Permafrost Open Session is a platform for the presentation and discussion of current research focusing on (a) permafrost and associated natural systems; (b) the interaction of permafrost and climate; (c) the impact of permafrost changes on both, natural and human systems; and (d) the measurement, understanding, modeling, and parameterization of corresponding processes. Contributions are welcome on high-latitude, mountain, and planetary permafrost.
Our program has two parts this year: Part 1, Morning, General Contributions; Part 2, Afternoon, Retrogressive Thaw Slumps.

We look forward to a high-quality session with a high number of contributions that reflect diverse scientific fields, approaches, and geographic locations. We would like to especially encourage contributions that (a) present novel measurement and monitoring approaches; (b) present new strategies to improve process understanding; (c) come from or interface with differing fields of science or innovative technologies and methods; (d) investigate model validation, model uncertainty, or spatial and temporal scale/scalability; (e) couple models of diverse processes or scales.

The Permafrost Open Session complements several other sessions with more specific foci (such as natural hazards, geophysics, or geomorphology) and is intended to be the forum for research primarily focusing on permafrost phenomena.

This year we also have a special section on retrogressive thaw slumps, rapid degradation features in ice-rich permafrost. This section focuses on (1) modern thaw slumps dynamics monitored by onsite and remote sensing as well as geophysical methods, (2) on quality and quantity of released material and its impact on adjacent ecosystems, and (3) on still preserved Quaternary inventories of fossil organic matter and ground ice that are accessible in thaw slump headwalls.

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Convener: Reginald Muskett | Co-conveners: Florence Magnin, Michael Krautblatter, Sebastian Wetterich, Thomas Opel, Trevor Porter, Melissa Ward JonesECSECS
Displays
| Chat Tue, 05 May, 10:45–12:30, Chat Tue, 05 May, 14:00–15:45
ITS5.9/EOS4.14

World-wide an increasing number of research projects focus on the challenges associated with changes in the Arctic regions. Whereas these often have a natural and physical science focus, this session focuses on trans-disciplinary approaches to study the multiple phenomena associated with global warming, especially but not exclusively in Arctic regions. Another focus is to understand better how to tackle these in large, trans-disciplinary research projects, initiatives and programs (e.g. HORIZON2020 Nunataryuk, INTAROS and the T-MOSAIC program of the International Arctic Research Council, NSF Navigating the New Arctic), as well as communicating results effectively to the public in terms of outreach and education. Contributions are invited, but are not limited, to the following themes:
• science communication, education and outreach tools, and co-production of knowledge
• integration of social and natural science approaches
• indigenous and collaborative approaches to adaptation and mitigation, equitable mitigation, and risk perception
• socio-economic modelling in relation to Arctic environmental change,
• examining the impacts of permafrost thaw and other phenomena on health and pollution as well as infrastructure (and consequences of the built environment).

One of the aims of this session is to bring together researchers from both social and natural sciences who are involved or interested in reaching out to stakeholders and the general public, and share successful experiences. Examples from past, ongoing and future initiatives that include traditional indigenous knowledge and scientific tools and techniques are welcome.

This session merged from

ITS5.9/EOS4.14
Trans-disciplinary aspects of researching permafrost thaw: science communication, integration, monitoring, modelling and risk perception
Co-organized by CL4/CR4/GM7/HS12/NH9
Convener: Peter Schweitzer | Co-conveners: Annett Bartsch, Susanna Gartler

EOS4.1
Where human and natural systems meet: promoting innovative tools for Arctic outreach and education
Convener: Terenzio zenone | Co-conveners: Frederic Bouchard, Stein Sandven, Ylva Sjöberg, Donatella zona

CR4.5
Towards collaborative frameworks for permafrost research that incorporate northern principles: challenges and opportunities
Convener: Peter Morse | Co-conveners: Ryley Beddoe, Hugh O'Neill, Ashley Rudy, Greg Sieme

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Co-organized by CL4/CR4/GM7/HS12/NH9
Convener: Peter Schweitzer | Co-conveners: Susanna GartlerECSECS, Annett Bartsch, Terenzio zenone, Frederic Bouchard, Stein Sandven, Donatella Zona, Ylva Sjöberg
Displays
| Chat Fri, 08 May, 08:30–10:15
BG4.3

Permafrost thaw is expected to amplify the release of previously frozen material from terrestrial into aquatic systems: rivers, lakes, groundwater and oceans. Current projections include changes in precipitation patterns, active layer drainage and leaching, increased thermokarst lake formation, as well as increased coastal and river bank erosion that are further enhanced by rising water temperatures, river discharge and wave action. In addition, subsea permafrost that formed under terrestrial conditions but was later inundated might be rapidly thawing on Arctic Ocean shelves. These processes are expected to substantially alter the biogeochemical cycling of carbon but also of other elements in the permafrost area.
This session invites contributions on the mobilization of terrestrial matter to aquatic systems in the permafrost domain, as well as its transport, processing and potential interaction with autochthonous, aquatic matter. We encourage submissions focusing on organic and inorganic carbon as well as on other elements such as nitrogen, phosphorus, silica, iron, mercury and others, from all parts of the global permafrost area including mountain, inland, coastal and subsea permafrost, on all spatial scales, in the contemporary system but also in the past and future, based on field, laboratory and modelling work.

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Co-organized by CR4/HS13
Convener: Birgit WildECSECS | Co-conveners: Lisa BröderECSECS, Örjan Gustafsson
Displays
| Chat Fri, 08 May, 10:45–12:30
GM7.1

Present-day glacial and periglacial processes in cold regions, i.e. arctic and alpine environments, provide also modern analogues to processes and climatic changes that took place during the Pleistocene, including gradual retreat or collapse of ice sheets and mountain glaciers, and thawing and shrinking of low-land permafrost. Current geomorphological and glaciological changes in mid-latitude mountain ranges could also serve as a proxy for future changes in high-latitude regions within a context of climate change. Examples are speed-up or disintegration of creeping permafrost features or the relictification of rock glaciers.

For our session we invite contributions that either:
1. investigate present-day glacial and/or periglacial landforms, sediments and processes to describe the current state, to reconstruct past environmental conditions and to predict future scenarios in cold regions; or
2. have a Quaternary focus and aim at enhancing our understanding of past glacial, periglacial and paraglacial processes, also through the application of dating techniques.

Case studies that use a multi-disciplinary approach (e.g. field, laboratory and modelling techniques) and/or that highlight the interaction between the glacial, periglacial and paraglacial cryospheric components in cold regions are particularly welcome.

Keynote lectures:
Britta Sannel (Stockholm): Landscape dynamics in permafrost peatlands - past, present and uncertain future
Clare Boston (Portsmouth): The response of Østre Svartisen icefield, Norway, to 20th/21st Century climate change

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Co-organized by CL4/CR4
Convener: Andreas Kellerer-Pirklbauer | Co-conveners: Natacha Gribenski, Isabelle Gärtner-Roer, Sven Lukas
Displays
| Chat Thu, 07 May, 08:30–10:15
GM7.2

Mountain glaciations provide an invaluable record for past and present climate change. The utilization of this potential is, however, not trivial because of the wide diversity of formerly and currently glaciated mountain ranges. In addition to their dynamic, complex, and interacting geomorphological process-systems, the specific different climatic and glaciological conditions make any subsequent global or intra-hemispheric correlations incredibly challenging. This problem is further enhanced by ongoing specialisation within the scientific community. Working groups primarily focusing on either individual aspects or selected mountain regions often remain somewhat disconnected. Only if significant bridging between specialised research communities is guaranteed, progress with the understanding of the complex interactions within mountain ranges can be achieved.
The primary aim of this session is to evaluate the potential of mountain glaciations records and stimulate further research in this important field of research. Contributions on all relevant aspects of the topic are welcomed, for example: (a) glacial landforms and reconstruction of past glaciers, (b) dating techniques and geochronology compilations, (c) glacier dynamics and palaeoclimatic interpretations, or (d) impacts of ecosystems and human evolution/society. Submissions targeting these connections are specifically encouraged. While we encourage submitting abstracts from all abovementioned topics within the broad field of mountain glaciations, we would like to invite in particular those highlighting the specific conditions of mountain glaciations or addressing the relationship and connections between different of their aspects. To address the diversity of mountain glaciations, contributions from high-, middle-, and low-latitude mountain ranges as well as from continental to maritime regions are all welcomed. The time scale of the session will cover the whole time range from Early Pleistocene glaciations to the LGM and Holocene/modern glaciers.

Solicited talk: Ann Rowan "Accelerating recent mass loss from debris-covered Khumbu Glacier in Nepal, and projected response to climate change by 2200 CE"

The session is a platform for everyone interested in the emerging collaborative research network “The Legacy of Mountain Glaciations” and a related splinter meeting (SMP 1) is scheduled for Wednesday, May 6th at 12.45 in room: 0.51. Please use this opportunity to meet and exchange ideas and expertise.

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Co-organized by CR4/SSP2
Convener: Stefan Winkler | Co-conveners: Lauren KnightECSECS, Giovanni Monegato, Jürgen Reitner
Displays
| Chat Thu, 07 May, 10:45–12:30
SSP3.21

Bedrock depressions are common features of past and modern glacial landscapes. They are often referred to as overdeepenings and act as important terrestrial archives. Which processes control the formation and geometry of glacial overdeepenings? How did they evolve over time? Which chronological and environmental information can be derived from the sedimentary record? These are the questions that will be addressed in this session.

The timing, extent and driving mechanisms for the last major glacial cycle are increasingly better understood but remain poorly constrained for previous cycles. The early conceptual models, initially adopted to understand older glaciations, neglected much of the spatial and temporal complexity of glaciations. Furthermore, they suffered from a lack of constraining data, which is mainly due to the surficial incompleteness of the terrestrial records.
Some of these limitations may be overcome by studying the sedimentary infill of subglacially formed basins. It is generally accepted that glacial processes, supported by subglacial water, have carved these overdeepenings. However, considerable uncertainties remain concerning the erosional mechanisms and physical constraints.
The sedimentary record in overdeepenings is diverse, including glacial, glacio-lacustrine and fluvial sediments. Investigated records suggest that many overdeepened basins contain a multi-cycle infilling and erosion history. Overdeepenings may therefore act as sediment storages on the timescale of several glacial-interglacial cycles, and provide a valuable record of a landscape’s glacial history. The combination of sedimentological, geophysical, and chronological methods together with the application of landscape evolution models provides new insights into the development of these bedrock features and allows constraining the environmental conditions in the geological past.

This session shall stimulate discussions concerning the formation of subglacial depressions and that aim at deciphering the sedimentary fill of overdeepenings. Contributions may include investigations based on field observations and/or modelling of modern, Quaternary and pre-Quaternary glacial settings. Possible topics cover: (a) glacial and interglacial stratigraphic successions preserved in overdeepenings, (b) subglacial erosion and deposition, (c) glaciation chronology, and (d) landscape evolution.

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Co-organized by CR4/GM7, co-sponsored by IAS
Convener: Michael SchwenkECSECS | Co-conveners: Marius BuechiECSECS, Thomas BurschilECSECS, Urs Fischer, Bernhard Salcher
Displays
| Chat Mon, 04 May, 10:45–12:30

CR5 – lce sheets, ice shelves and glaciers

CR5.1

The increasing availability of remotely sensed observations and computational capacity, drive modelling and observational glacier studies towards increasingly large spatial scales. These large scales are of particular relevance, as they impact policy decisions and public discourse. In the European Alps, for instance, glacier changes are important from a touristic perspective, while in High Mountain Asia, glaciers are a key in the region’s hydrological cycle. At a global scale, glaciers are among the most important contributors to present-day sea level change.

This session focuses on advances in observing and modelling mountain glaciers and ice caps at the regional to global scale. We invite both observation- and modelling-based contributions that lead to a more complete understanding of glacier changes and dynamics at such scales.

Contributions may include, but are not limited to, the following topics:
• Observation and modelling results revealing previously unappreciated regional differences in glacier changes or in their dynamics;
• Large-scale impact studies, including glaciers' contribution to sea level change, or changes in water availability from glacierized regions;
• Advances in regional- to global-scale glacier models, e.g. inclusion of physical processes such as ice dynamics, debris-cover effects, glacier calving, or glacier surging;
• Regional to global scale process-studies, based on remote sensing observations or meta-analyses of ground-based data;
• Innovative combinations of observation and modelling techniques, for example blending different remote sensing products, or integrating machine learning algorithms;
• Inverse modelling of subglacial characteristics or glacier ice thickness at regional scales.

Note that this session is organized as a PICO.

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Convener: Daniel Farinotti | Co-conveners: Fanny BrunECSECS, Fabien MaussionECSECS, Harry ZekollariECSECS
Displays
| Chat Thu, 07 May, 16:15–18:00
CR5.2

This session is intended to attract a broad range of ice-sheet and glacier modelling contributions, welcoming applied and theoretical contributions. Theoretical topics that are encouraged are higher-order mechanical models, data inversion and assimilation, representation of other earth sub-systems in ice-sheet models, and the incorporation of basal processes and novel constitutive relationships in these models.

Applications of newer modelling themes to ice-sheets and glaciers past and present are particularly encouraged, in particular those considering ice streams, rapid change, grounding line motion and ice-sheet model intercomparisons.

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Convener: Fabien Gillet-Chaulet | Co-conveners: Stephen Cornford, Gael Durand, Sainan Sun
Displays
| Chat Wed, 06 May, 08:30–10:15
CR5.4

Ice sheets play an active role in the climate system by amplifying, pacing, and potentially driving global climate change over a wide range of time scales. The impact of interactions between ice sheets and climate include changes in atmospheric and ocean temperatures and circulation, global biogeochemical cycles, the global hydrological cycle, vegetation, sea level, and land-surface albedo, which in turn cause additional feedbacks in the climate system. This session will present data and modelling results that examine ice sheet interactions with other components of the climate system over several time scales. Among other topics, issues to be addressed in this session include ice sheet-climate interactions from glacial-interglacial to millennial and centennial time scales, the role of ice sheets in Cenozoic global cooling and the mid-Pleistocene transition, reconstructions of past ice sheets and sea level, the current and future evolution of the ice sheets, and the role of ice sheets in abrupt climate change.

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Co-organized by CL4
Convener: Heiko Goelzer | Co-conveners: Alexander Robinson, Ricarda Winkelmann, Philippe Huybrechts, Stefanie MackECSECS
Displays
| Chat Wed, 06 May, 10:45–12:30
CR5.7

Ice shelves and tidewater glaciers are sensitive elements of the climate system. Sandwiched between atmosphere and ocean, they are vulnerable to changes in either. The recent disintegration of ice shelves such as Larsen B and Wilkins on the Antarctic Peninsula, current thinning of the ice shelves in the Amundsen Sea sector of West Antarctica, and the recent accelerations of many of Greenland's tidewater glaciers provide evidence of the rapidity with which those systems can respond. Changes in marine-terminating outlets appear to be intimately linked with acceleration and thinning of the ice sheets inland of the grounding line, with immediate consequences for global sea level. Studies of the dynamics and structure of the ice sheets' marine termini and their interactions with atmosphere and ocean are the key to improving our understanding of their response to climate forcing and of their buttressing role for ice streams. The main themes of this session are the dynamics of ice shelves and tidewater glaciers and their interaction with the ocean, atmosphere and the inland ice, including grounding line dynamics. The session includes studies on related processes such as calving, ice fracture, rifting and mass balance, as well as theoretical descriptions of mechanical and thermodynamic processes. We seek contributions both from numerical modelling of ice shelves and tidewater glaciers, including their oceanic and atmospheric environments, and from observational studies of those systems, including glaciological and oceanographic field measurements, as well as remote sensing and laboratory studies.

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Co-organized by OS1
Convener: Adrian Jenkins | Co-conveners: Rachel CarrECSECS, Angelika Humbert, Nicolas Jourdain, Inga Monika Koszalka
Displays
| Chat Fri, 08 May, 14:00–15:45, Chat Fri, 08 May, 16:15–18:00
CR5.8

Dynamic subglacial and supraglacial water networks play a key role in the flow and stability of ice sheets. The accumulation of meltwater on the surface of ice shelves has been hypothesized as a potential mechanism controlling ice-shelf stability, with ice-shelf collapse triggering substantial increases in discharge of grounded ice. Observations and modelling also suggest that complex hydrological networks occur at the base of glaciers and these systems play a prominent role in controlling the flow of grounded ice. This session tackles the urgent need to better understand the fundamental processes involved in glacial hydrology that need to be addressed in order to accurately predict future ice-sheet evolution and mass loss, and ultimately the contribution to sea-level rise .
We seek contributions from both the modelling and observational communities relating to any area of ice-sheet hydrology. This includes but is not limited to: surface hydrology, melt lake and river formation; meltwater processes within the ice and firn; basal hydrology; subglacial lakes; impacts of meltwater on ice-sheet stability and flow; incorporation of any of these processes into large-scale climate and ice-sheet models.

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Co-organized by HS2.1
Convener: Sammie BuzzardECSECS | Co-conveners: Ian Hewitt, Amber Leeson, Martin WearingECSECS
Displays
| Chat Fri, 08 May, 08:30–10:15
CR5.9

Subglacial environments are among the least accessible regions on Earth and represent one of the last physical frontiers of glaciological research, while emerging as a unique ecological habitat. The subglacial environment is a key component in the dynamic behaviour of ice sheets and glaciers, involving complex and precise mass and energy transfers between the ice and its substrate of water, air, bedrock, or sediment, and the oceans at ice sheet boundaries. In particular, determining the distribution and nature of water flows at the ice-mass bed is highlighted as a priority for understanding and predicting ice dynamics. For example, both remote sensing and ground-based observations across Antarctica and Greenland highlight the existence of subglacial water in a variety of forms, ranging from vast subglacial lakes (providing distinctive habitats for potentially unique life forms) to mm-thick water flows at the ice-substrate interface. Feedbacks between increased surface melting, glacier bed conditions and ice flow also affect alpine glaciers, potentially contributing to increased glacial retreat in low and mid-latitude mountain regions.

It is clear that subglacial processes impact ice dynamics, transcending ice-mass scales from valley glaciers to large ice sheets and, through feedback loops, contribute to changes in sea level, ocean circulation, and climate evolution. Quantitative characterisation of the basal environment therefore remains an outstanding glaciological problem, as does scaling of this knowledge for use in modelling ice sheet and glacier behaviour.

We invite scientific contributions that include, but are not limited to, measurements and/or modelling of: (i) flow of subglacial water at the bed and through subglacial sediments; (ii) linkages between subglacial hydrology and ice dynamics; (iii) theoretical-, field-, or laboratory-based parameterisation of subglacial processes in numerical ice-flow models; (v) formation, geometry and potential hydrological linkages between subglacial lakes; (v) subglacial and supraglacial lake drainage and subglacial floods from ice margins; and (vi) geomorphological evidence of subglacial water flows from contemporary ice-sheet margins and across formerly glaciated continental-scale regions.

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Convener: Adam Booth | Co-conveners: Robert Bingham, Christine Dow, Bryn Hubbard, Harold Lovell
Displays
| Chat Fri, 08 May, 10:45–12:30

CR6 – Sea Ice

CR6.2

Recent years have seen significant reductions in Arctic sea ice extent, and a redistribution of sea ice in the Antarctic. Climate projections suggest a reduction of the sea ice cover in both poles, with the Arctic becoming seasonally ice free in the latter half of this century.

The scientific community is investing considerable effort in organising our current knowledge of the physical and biogeochemical properties of sea ice, exploring poorly understood sea ice processes, and forecasting future changes of the sea ice cover.

In this session, we invite contributions regarding all aspects of sea ice science and sea ice-climate interactions, including snow and sea ice thermodynamics and dynamics, sea ice-atmosphere and sea ice-ocean interactions, sea ice biological and chemical processes, and sea ice models. A focus on emerging processes and implications is particularly welcome.

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Co-organized by OS1
Convener: Daniel Feltham | Co-conveners: Daniela Flocco, Andrew Wells, Shiming Xu, Vishnu NandanECSECS
Displays
| Chat Mon, 04 May, 08:30–10:15
OS1.13

In recent years the interaction between the ocean and the cryosphere in the marginal seas of the Southern Ocean has become a major focus in climate research. Questions such as "Why has Antarctic sea ice only recently begun to decline?", "What controls the inflow of warm water into ice shelf cavities and how does it interact with the ice?", and “What are the dominant processes in ice-ocean boundary layers?” have attracted scientific and public attention. Recent advances in observational technology, data coverage, and modeling provide scientists with a better understanding of the mechanisms involving ice-ocean interactions of various types in the far South. Processes on the Antarctic continental shelf have been identified as missing links between the cryosphere, the global atmosphere and the deep open ocean that need to be captured in large-scale and global model simulations. Similarly, our limited knowledge of processes in ice-ocean boundary layers, such as heat and salt fluxes that control the melt rate, has been identified as a limitation on our ability to fully understand, let alone parameterize melting and freezing at interfaces between the ocean and ice shelves, icebergs, glaciers, and sea ice.

This session includes studies of the Southern Ocean's marginal seas including the Antarctic continental shelf and ice shelf cavities, as well as process studies with a particular focus on ice-ocean boundary layers and on all scales, from the ice-ocean interface to local to basin-scale to circumpolar. Physical and biogeochemical interactions between ice shelves, sea ice and the open ocean will be presented, along with their impacts on the greater Antarctic climate system. Presentations include theoretical studies as well as those based on in-situ observations, remote sensing, and process-scale, regional and global models. While the primary focus of the session is on ice-ocean interactions, we also includes contributions on ice-covered freshwater lakes.

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Co-organized by BG4/CL2/CR6
Convener: Xylar Asay-Davis | Co-conveners: Louis-Alexandre CoustonECSECS, Leo Middleton, Nadine SteigerECSECS, Irena VankovaECSECS
Displays
| Chat Thu, 07 May, 16:15–18:00
OS1.11

The rapid decline of Arctic sea ice in the last decade is a dramatic indicator of climate change. The Arctic sea ice cover is now thinner, weaker and drifts faster. The ocean is also changing; the volume of freshwater stored in the Arctic and has increased as have the inputs of coastal runoff from Siberia and Greenland. Concurrently inflows from the Atlantic and Pacific Oceans have warmed. As the global surface temperature rises, the Arctic Ocean is speculated to become seasonally ice-free in the 21st century, which prompts us to revisit our perceptions of the Arctic system as a whole. What could the Arctic look like in the future? How are the present changes in the Arctic going to affect the lower latitudes? What aspects of the changing Arctic should future observations, remote sensing and modelling programmes address? The scientific community is investing considerable effort in making the current knowledge of the physical and biogeochemical properties of the Arctic more systematic, in exploring poorly understood coupled atmosphere-sea-ice-ocean processes to improve prediction of future changes in the Arctic.

In this session, we invite contributions from a variety of studies addressing the recent past, present and future Arctic. We encourage submissions examining interactions between the ocean, atmosphere and sea ice and on studies linking changes in the Arctic to the global ocean. Submissions with a focus on emerging cryospheric, oceanic and biogeochemical processes and their implications are particularly welcome.

The session promotes results from current Arctic programmes and discussions on future plans for Arctic Ocean modelling and measurement strategies, and encourage submissions on the results from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC).

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Co-organized by AS4/BG4/CL2/CR6
Convener: Yevgeny Aksenov | Co-conveners: Paul A. Dodd, Céline Heuzé, Krissy Reeve
Displays
| Chat Thu, 07 May, 08:30–12:30

CR7 – The cryosphere in the Earth system: interdisciplinary topics

CR7.1

Decreasing sea-ice coverage, increasing permafrost-derived inputs and increasing ice sheet and glacier discharge will continue to affect high latitude environments in the coming decades under all future climate scenarios. Such changes at the interface between the ocean and the cryosphere raise questions about the downstream effects in marine ecosystems, as increased meltwater discharge is likely to impact not only coastal hydrology but also biogeochemistry, sediment transport and ecosystem services such as fisheries and carbon sequestration. However, the impact of increasing melt on fjord and coastal environments is poorly constrained, impacting our ability to make predictions regarding the consequences of future climate change. In order to understand the effect of changing cryosphere-derived inputs on high latitude fjords and marine coastal environments, knowledge concerning the physical and biochemical perturbations occurring in the sea ice and water column and the structure, function and resilience of affected ecosystems must be integrated. In this session we explicitly welcome cross-disciplinary attempts to understand how far reaching the effects of sea-ice, permafrost derived material and glacial changes are on marine biogeochemistry, productivity, biodiversity, and ecosystem services. Topics may include, yet are not limited to, the effect of sea-ice, permafrost, and glacier discharge on sea-ice and water column structure, primary and secondary production, community structure, macronutrient and micronutrient availability, microbial processes, the carbonate system, and the biological carbon pump. Modelling experiments, and studies based on long-term observational records including sediment traps and proxy reconstructions from marine sediment cores are also welcome.

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Co-organized by BG4/CL4/OS3
Convener: Sofia Ribeiro | Co-conveners: Jade HattonECSECS, Mark HopwoodECSECS, Letizia Tedesco, Anna Pienkowski, Jonathan HawkingsECSECS, Susann Henkel, Hong Chin NgECSECS
Displays
| Chat Thu, 07 May, 16:15–18:00
CL4.13

One of the most striking features of global climate change is the strongly amplified response of surface air temperature in the Arctic and the associated strong decline in sea ice. Both observational and climate modeling studies have shown that the Arctic is a region very susceptible to climate change; moreover, changes occurring in the Arctic are likely to have more wide-spread implications. Arctic amplification manifests itself in a number of ways, most notably in the current retreat and thinning of Arctic sea ice. A variety of processes and feedbacks have been proposed that contribute to amplified Arctic warming, most of them associated with sea ice. The most well-known is the surface-albedo feedback, which is associated with retreating sea-ice and snow cover. While most climate models exhibit an Arctic amplification signal with respect to ongoing and future changes, the inter-model range in simulated amplification is large, suggesting that the magnitudes of the various feedbacks contributing to Arctic warming and the role of sea ice therein are still uncertain. This session specifically aims to identify, characterize and quantify the processes and feedbacks that govern amplified Arctic warming and sea ice retreat, and it also addresses the climate impacts on the lower latitudes associated with Arctic changes (for instance the relation between sea ice reductions, heat flux changes and atmospheric circulation changes beyond the Arctic region). We therefore invite contributions on the causes, mechanisms and climate feedbacks associated with Arctic climate change and sea ice decline, and the possible links to weather and climate outside the Arctic. We welcome studies based both on climate model results and/or observational datasets, for near-past, present and future climate changes.

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Co-organized by AS4/CR7
Convener: Richard Bintanja | Co-convener: Rune Grand Graversen
Displays
| Chat Tue, 05 May, 16:15–18:00
CL4.14

The Arctic Realm is changing rapidly and the fate of the cryosphere, including Arctic sea ice, glaciers and ice caps, is a source of concern. Whereas sea ice variations impact the radiative energy budget, thus playing a role in Arctic amplification, the Greenland Ice Sheet retreat contributes to global sea level rise. Moreover, through various processes linking the atmosphere, ice and ocean, the change in the Arctic realm may modify the atmospheric and ocean circulation at regional to global scales, the freshwater budget of the ocean and deep-water formation as well as the marine and terrestrial ecosystems. The processes and feedbacks involved operate on all time scales and thus require several types of information: satellite and instrumental data, climate models, and reconstructions based on geological archives. In this session, we invite contributions from a range of disciplines and across time scales, including observational data, historical data, proxy data, model simulations and forecasts, for the past, present and future climate. The common denominator of these studies will be their focus on a better understanding of mechanisms and feedbacks on short to long time scales that drive Arctic and subarctic changes and their impact on climate, ocean and environmental conditions, at regional to global scales, including possible links to weather and climate outside the Arctic.

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Co-organized by CR7/OS1
Convener: Marit-Solveig Seidenkrantz | Co-conveners: Anne de Vernal, Michal Kucera, Mimmi OksmanECSECS, Henrieka Detlef
Displays
| Chat Mon, 04 May, 16:15–18:00
ITS2.15/BG2.25

This session is linked to the Pan-Eurasian EXperiment (PEEX; www.atm.helsinki.fi/peex), a multi-disciplinary, -scale and -component climate change, air quality, environment and research infrastructure and capacity building programme. It is aimed at resolving major uncertainties in Earth system science and global sustainability issues concerning the Arctic, Northern Eurasia and China regions. This session aims to bring together researchers interested in (i) understanding environmental changes effecting in pristine and industrialized Pan-Eurasian environments (system understanding); (ii) determining relevant environmental, climatic, and other processes in Arctic-boreal regions (process understanding); (iii) the further development of the long-term, continuous and comprehensive ground-based, air/seaborne research infrastructures together with satellite data (observation component); (iv) to develop new datasets and archives of the continuous, comprehensive data flows in a joint manner (data component); (v) to implement validated and harmonized data products in models of appropriate spatio-temporal scales and topical focus (modeling component); (vi) to evaluate impact on society though assessment, scenarios, services, innovations and new technologies (society component).
List of topics:
• Ground-based and satellite observations and datasets for atmospheric composition in Northern Eurasia and China
• Impacts on environment, ecosystems, human health due to atmospheric transport, dispersion, deposition and chemical transformations of air pollutants in Arctic-boreal regions
• New approaches and methods on measurements and modelling in Arctic conditions;
• Improvements in natural and anthropogenic emission inventories for Arctic-boreal regions
• Physical, chemical and biological processes in a northern context
• Aerosol formation-growth, aerosol-cloud-climate interactions, radiative forcing, feedbacks in Arctic, Siberia, China;
• Short lived pollutants and climate forcers, permafrost, forest fires effects
• Carbon dioxide and methane, ecosystem carbon cycle
• Socio-economical changes in Northern Eurasia and China regions.
PEEX session is co-organized with the Digital Belt and Road Program (DBAR), abstracts welcome on topics:
• Big Earth Data approaches on facilitating synergy between DBAR activities & PEEX multi-disciplinary regime
• Understanding and remote connection of last decades changes of environment over High Asia and Arctic regions, both land and ocean.

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Co-organized by AS4/CL2/CR7/GI6
Convener: Markku Kulmala | Co-conveners: Alexander Baklanov, Hanna Lappalainen, Sergej Zilitinkevich
Displays
| Chat Fri, 08 May, 10:45–12:30, Chat Fri, 08 May, 14:00–15:45
ITS3.1/NP1.2

Several subsystems of the Earth system have been suggested to react abruptly at critical levels of anthropogenic forcing. Well-known examples of such Tipping Elements include the Atlantic Meridional Overturning Circulation, the polar ice sheets and sea ice, tropical and boreal forests, as well as the Asian monsoon systems. Interactions between the different Tipping Elements may either have stabilizing or destabilizing effects on the other subsystems, potentially leading to cascades of abrupt transitions. The critical forcing levels at which abrupt transitions occur have recently been associated with Tipping Points.

It is paramount to determine the critical forcing levels (and the associated uncertainties) beyond which the systems in question will abruptly change their state, with potentially devastating climatic, ecological, and societal impacts. For this purpose, we need to substantially enhance our understanding of the dynamics of the Tipping Elements and their interactions, on the basis of paleoclimatic evidence, present-day observations, and models spanning the entire hierarchy of complexity. Moreover, to be able to mitigate - or prepare for - potential future transitions, early warning signals have to be identified and monitored in both observations and models.

This interdisciplinary session invites contributions that address Tipping Points in the Earth system from the different perspectives of all relevant disciplines, including

- the mathematical theory of abrupt transitions in (random) dynamical systems,
- paleoclimatic studies of past abrupt transitions,
- data-driven and process-based modelling of past and future transitions,
- early-warning signals
- the implications of abrupt transitions for Climate sensitivity and response,
- ecological and societal impacts, as well as
- decision theory in the presence of uncertain Tipping Point estimates

Confirmed invited speaker: Michael Ghil

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Including Lewis Fry Richardson Medal Lecture
Co-organized by CL4/CR7/OS1
Convener: Niklas BoersECSECS | Co-conveners: Peter Ditlevsen, Timothy Lenton , Anna von der Heydt, Ricarda Winkelmann
Displays
| Chat Wed, 06 May, 08:30–12:30
CL4.2

State of the art climate models are now run for past, present and future climates. This has opened up the opportunity for paleoclimate modelling and data together to inform on future climate changes. To date, most research in this area has been on constraining basic metrics such a climate sensitivity. In addition, and just as importantly for mankind, the Earth's climate is highly variable on all spatial and temporal scales with implications for understanding both the industrial epoch
and future climate projections. These changes in variability (spatial or temporal) can impact the recurrence frequency of extreme events which can have catastrophic effects on society. Yet, it is unclear if a warmer future is one with more or less climate variability, and at which scales. A multitude of feedbacks are involved.

We welcome contributions that improve quantification, understanding and prediction of past, present and future climate and its variability in the Earth System across space and time scales. This includes contributions looking at "steady state" climate features such as climate sensitivity as well as those investigating changes in climate variability and scaling properties. The session is multidisciplinary and brings together studies related to atmospheric science, oceanography, glaciology, paleoclimatology and nonlinear geoscience, to examine the complementarity of ideas and approaches. We particularly encourage submissions that combine models run for the past, present and future with data syntheses to constrain the spread of future predictions, submissions which combine models and data in the past to make strong conclusions or testable hypotheses about the future, as well as work highlighting future experiments and data required to strengthen the link to the future. We welcome contributions using case studies, idealised or realistic modelling, synthesis, and model-data comparison studies that provide insights into past, present and future climate variability on local to global, and synoptic to orbital timescales. Members of the PAGES working group on Climate Variability Across Scales (CVAS) are welcome.

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Co-organized by AS4/CR7/NP3/OS1
Convener: Julia Hargreaves | Co-conveners: Kira Rehfeld, Thomas Laepple, Shaun Lovejoy
Displays
| Chat Fri, 08 May, 14:00–15:45
AS2.2

Changes in the Arctic and Antarctic climate systems are strongly related to processes in the boundary layer and their feedbacks with the free troposphere, ocean and ice. An adequate understanding and quantification of these processes is necessary to improve predictions of future changes in the polar regions and their teleconnection with mid-latitude weather and climate, including meridional transport of heat, moisture and chemical constituents. Processes include atmosphere-ocean-ice (AOI) interactions, physical and chemical snow processes (e.g. snow photochemistry), exchange of chemical constituents including biogeochemical impacts , sources of aerosol, polynya formation processes, sea ice production and loss, and cloud formation, which represent key processes for the atmosphere, ocean and the cryosphere. AOI interactions are also triggered by and have feedbacks with synoptic systems and mesoscale weather phenomena such as cold air outbreaks, katabatic winds and polar lows. Associated processes also include the effect of extreme events such as warm air advection and clouds on the surface energy budget and related boundary layer exchanges. In addition, understanding natural processes including AOI interactions is essential to understand of the background atmosphere to quantify the anthropogenic impacts. Shallow inversions, mostly during winter-time, lead to high air pollutant concentrations. Even though severe air pollution episodes are frequently observed in the Arctic, knowledge on urban emission sources, transport and atmospheric chemical processing of pollution, especially under cold and dark conditions, are poorly understood. Similarly, the polar boundary layer can involve complicated radiative processes such as shallow stable layers with fog present. In addition, polar boundary layers can mediate chemical, aerosol, and isotope exchanges between the atmosphere and the firn important to the interpretation of ice core records.
This session is intended to provide an interdisciplinary forum to bring together researchers working in the area of boundary layer processes and high-latitude weather and climate (including snow physics, air/snow chemistry, and oceanography). Cryosphere and atmospheric chemistry processes (the focus of the IGAC/SOLAS activity “CATCH” and the IGAC/IASC activity “PACES”) are highly relevant to this session. We also encourage preliminary results from field programs such as MOSAiC and other high-latitude research efforts.

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Co-organized by CL2/CR7/OS1
Convener: William Neff | Co-conveners: Jo Browse, Julia Schmale, Michael Tjernström, Gillian Young
Displays
| Chat Mon, 04 May, 08:30–10:15
AS2.8

Clouds play an important role in the polar climate due to their interaction with atmospheric radiation and their role in the hydrological cycle linking poleward water vapour transport with precipitation, thereby affecting the mass balance of the polar ice sheets. Cloud-radiative feedbacks have also an important influence on sea ice. Cloud and precipitation properties depend strongly on the atmospheric dynamics and moisture sources and transport, as well as on aerosol particles, which can act as cloud condensation and ice nuclei.

This session aims at bringing together researchers using observational and/or modeling approaches (at various scales) to improve our understanding of polar tropospheric clouds, precipitation, and related mechanisms and impacts. Contributions are invited on various relevant processes including (but not limited to):


- Drivers of cloud/precipitation microphysics at high latitudes,
- Sources of cloud nuclei both at local and long range,

- Linkages of polar clouds/precipitation to the moisture sources and transport,

- Relationship of the poleward moisture transport to processes in the tropics and extra-tropics, including extreme transport events (e.g., atmospheric rivers, moisture intrusions),

- Relationship of moisture/cloud/precipitation processes to the atmospheric dynamics, ranging from synoptic and meso-scale processes to teleconnections and climate indices,

- Role of the surface-atmosphere interaction in terms of mass, energy, and cloud nuclei particles (evaporation, precipitation, albedo changes, cloud nuclei sources, etc)
- Impacts that the clouds/precipitation in the Polar Regions have on the polar and global climate system, surface mass and energy balance, sea ice and ecosystems.

Papers including new methodologies specific to polar regions are encouraged, such as (i) improving polar cloud/precipitation parameterizations in atmospheric models, moisture transport events detection and attribution methods specifically in the high latitudes, and (ii) advancing observations of polar clouds and precipitation. We would like to emphasize collaborative observational and modeling activities, such as the Year of Polar Prediction (YOPP), Polar-CORDEX, the (AC)3 project on Arctic Amplification, SOCRATES, ACE and other campaigns in the Arctic and Southern Ocean/Antarctica, and encourage related contributions.

The session is endorsed by the SCAR Antarctic Clouds and Aerosols Action Group.


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Co-organized by CL2/CR7
Convener: Irina V. Gorodetskaya | Co-conveners: Susanne Crewell, Tom Lachlan-Cope, Nicole van Lipzig, Manfred Wendisch
Displays
| Chat Wed, 06 May, 08:30–10:15
AS2.9

The polar climate system is strongly affected by interactions between the atmosphere and the cryosphere. Feedback mechanisms between snow, land ice, sea ice and the atmosphere, such as blowing snow, ice melt, polynya formation, and sea ice production play an important role. Atmosphere-ice interactions are also triggered by synoptic weather phenomena such as cold air outbreaks, katabatic winds, polar cyclones, atmospheric rivers, Foehn winds and heatwaves. However, our understanding of these processes is still incomplete, and to fully capture how atmosphere, land ice and sea ice are coupled on different spatial and temporal scales, remains a major challenge.
This session will provide a setting to foster discussion on the atmosphere-ice coupling in both the Northern and Southern Hemispheres. It will offer the opportunity to review newly acquired knowledge, identify gaps, and which instruments, tools, and studies can be designed to address these open questions.
We invite contributions on all observational and modelling aspects of Arctic and Antarctic meteorology and climatology that address atmospheric interactions with the cryosphere. This may include studies of atmospheric dynamics that influence sea-ice dynamics or ice-sheet mass balance, or investigations into the variability of the atmospheric circulation such as polar jets, the circumpolar trough, storm tracks and their link to changes in the cryosphere.

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Co-organized by CR7
Convener: Diana Francis | Co-conveners: Amélie Kirchgaessner, Till Wagner
Displays
| Chat Mon, 04 May, 16:15–18:00
CL4.17

Mountains cover approximately one quarter of the total land surface on the planet, and a significant fraction of the world’s population lives in their vicinity. Orography critically affects weather and climate processes at all scales and, in connection with factors such as land-cover heterogeneity, is responsible for high spatial variability in mountain weather and climate.

Due to this high complexity, monitoring and modeling the atmosphere and the other components of the climate system in mountain regions is challenging both at short (meteorological) and long (climatological) time-scales. This session is devoted to the better understanding of weather and climate processes in mountain and high-elevation areas around the globe, as well as their modification induced by global environmental change.

We welcome contributions describing the influence of mountains on the atmosphere on meteorological time-scales, including terrain-induced airflow, orographic precipitation, land-atmosphere exchange over mountains, forecasting and predictability of mountain weather. Furthermore we invite studies that investigate climate processes and climate change in mountain areas and its impacts on dependent systems, based on monitoring and modeling activities. Particularly welcome are contributions that merge various sources of information and reach across disciplinary borders (atmospheric, hydrological, cryospheric, ecological and social sciences). In this respect the session invites also contributions on outcomes of the WMO "High Mountain Summit" taking place in October 2019.

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Co-organized by AS1/CR7/NH1
Convener: Wolfgang Schöner | Co-conveners: Carolina Adler, Maria Vittoria Guarino, Elisa Palazzi, Stefano Serafin
Displays
| Chat Mon, 04 May, 14:00–15:45
ITS1.10/NH9.27

In this session, we invite contributions to explore diverse experiences with inter- and transdisciplinary research and practice, that is specifically applied in the mountain context. Taking mountains as complex social-ecological systems, they provide a concrete and spatially-defined contexts in which to explore how global change phenomena manifests and how it poses challenges and opportunities for communities and society in general.

Addressing societal concerns, and finding suitable solutions with regards to associated impacts of global change in mountains, requires and inter- and transdisciplinary (IT-TD) approach to research and practice. We invite contributions based on empirical research and/or practical experience with IT-TD, to critically reflect on these practices in the mountains context and learn from experiences that explicitly address societal grand challenges such as (but not limited to) climate change impacts and adaptation, transformations to sustainability, disaster risk reduction, or transitions to low carbon economies. We welcome contributions depicting research experiences in European mountain regions, other mountain regions around the world, as well as contributions from Early Career Researchers.

The session is led and coordinated by the Mountain Research Initiative (MRI) with expectations to be able to draw from this session as inputs for the formulation of future research agendas and coordination of research collaborations in mountain regions, worldwide.

www.mountainresearchinitiative.org

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Co-organized by EOS4/CL4/CR7/GM7
Convener: Carolina Adler | Co-convener: Aino Kulonen
Displays
| Chat Mon, 04 May, 14:00–15:45
ITS3.2/NH10.7

Climate change is projected to result in an increase in extreme and compound weather events, which pose a growing threat to human well-being and the achievement of the UN Sustainable Development Goals (SDGs). Further warming is also projected to reduce the efficacy of carbon sinks acting as negative feedbacks on warming and increase the risk of crossing tipping points and triggering cascading changes in the climate and ecosystems. These processes may reduce the Earth system’s resilience, which has the potential to further amplify climate change and extremes and worsen societal impacts.

Maintaining Earth in the Holocene-like conditions that have enabled the development of the world’s societies will require better understanding of feedbacks and tipping dynamics in both the human world and the biophysical Earth. Societies will need to embark on rapid socio-economic and governance transformations in order to both reduce the risk of triggering tipping points and to improve societal resilience to increasingly likely extreme events. Earth resilience brings the complex dynamics and perturbations associated with human activities into Earth system analysis, and increasingly captures socio-economic as well as biophysical dynamics.

In this session we welcome transdisciplinary and cross-scale contributions relating to climate extremes, tipping dynamics, and Earth resilience, covering topics ranging from the cascading impacts of extreme and compound events, key feedbacks and tipping points in both biophysical and human systems, enhancing societal resilience to extreme events, and the potential for rapid social transformations to global sustainability.

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Co-organized by BG1/CL2/CR7/NP8/OS1, co-sponsored by Future Earth
Convener: Felix Riede | Co-conveners: David Armstrong McKayECSECS, Jana Sillmann, Jonathan Donges, Dorothea Frank, Sarah Cornell, Ricarda Winkelmann
Displays
| Chat Wed, 06 May, 14:00–18:00

CR8 – Short courses

SC4.26

Are you an early career scientist coming to EGU looking for inspiration to take the next step in your career? Are you feeling a little lost with all the opportunities both academic and elsewhere? Then this short course is for you!

Join us for a panel discussion about everything to do with life post-polar-PhD and expand your ideas about where you might go next.

Our expert panelists come from a wide range of backgrounds, from various stages of academia to applied science, science project management and science journalism. They will give you a little background about their experience and career. Afterwards, we will open the floor to a chaired discussion about all aspects of their careers and it’s over to you! Want to know how to get into a certain career, what experience you might need and what working in a certain career entails – just go ahead and ask!

Come along to listen or participate in what will be a lively and informative discussion. The session is open to anyone at any level in their career. Questions and answers will also be live tweeted!

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Co-organized by CL6/CR8, co-sponsored by APECS
Convener: Stephen ChuterECSECS | Co-conveners: Ronja ReeseECSECS, Grace E. ShephardECSECS
Thu, 07 May, 14:00–15:45
SC3.15

Over the years, twitter has proven to be a popular and powerful tool for geoscientists. This platform can spread the latest news very efficiently, foster discussions on science and issues affecting scientists, extend professional networks within and beyond own fields of expertise, and promote the latest scientific research. Yet twitter can seem a scary place for someone just starting out.

This short course explores, as a panel discussion, the opportunities and caveats that twitter represents for geoscientists, with the aim of encouraging geoscientists to give it a go!

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Co-organized by AS6/CR8
Convener: Andy EmeryECSECS | Co-conveners: Sophie BergerECSECS, Fernando Iglesias-SuarezECSECS
Wed, 06 May, 14:00–15:45
SC1.16

Estimating climate trends and variability on interannual to orbital timescales from proxy records is an important task in paleoclimatology. However, chronological uncertainties, irregular sampling rates, temporally averaged measurements, and non-climatic influences on proxy records limit the applicability of standard statistical methods. In this short course, we demonstrate the effect of these properties on classical estimators and present a toolbox of statistical methods. The course is open to everybody and suitable for those without a strong statistical background.

In the first part, we present methods to estimate trends, variability, and spectra from univariate proxy time series. We begin by discussing methods to decompose times series into slow trends and fast variations, and then focus on spectral methods of analysis. Spectral methods allow the identification of cyclic behavior (spectral peaks), the study of scaling regimes (spectral slope), and the estimation of time scale specific variability (integration of the spectrum).
In the second part, we show robust methods to quantify simultaneous changes in time series. We begin with classical methods, which are based on cross-correlation. We then outline the use of a newer similarity measure, event synchronization, which is better suited to identify non-linear dependencies between records.
Finally, we explore hierarchical models for extracting common signals from spatially distributed proxy records and methods for non-Gaussian time series like percentage data.

In addition to presenting theoretical results from studying surrogate proxy records, we show examples for different proxy types (marine sediments, pollen, speleothems) and simulated time series. These examples use open source R packages and RMarkdown scripts which will allow the participants to follow the tutorials directly and easily apply the methods to their own datasets datasets.
The short course is a contribution to the PAGES working group CVAS.

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Co-organized by CL6/CR8/NP9
Convener: Nils WeitzelECSECS | Co-conveners: Raphael HébertECSECS, Kira Rehfeld
Fri, 08 May, 10:45–12:30
SC3.5

Research, especially for early-career scientists, starts with the spark of an idea and is then often challenged by empirical or methodological road bumps and seemingly dead ends. A diverse range of challenges faces those in Earth Science research, particularly early-career scientists (ECS). Challenges include (1) access difficulties, whether for field sites, equipment or data, (2) problems of scaling and extrapolation and (3) a lack of methodological understanding or knowledge. In this short course, we will raise engaging discussions, which aim to solve challenges, suggest new research approaches and methods, and encourage networks and possibilities for in-depth discussions amongst early-, mid- or late-career scientists at international conferences. This short course will start with 2 minute ‘pop-up’ presentations outlining the questions or challenges submitted by attendees. These pop-ups are followed by chaired group discussions in which short course participants engage to crowd solve the presented challenges. To wrap up the session, solutions and suggestions from each topical group are presented to the whole session in a final discussion. A summary of last years’ crowd solving efforts can be found in the EGU Geolog blog post under https://blogs.egu.eu/geolog/2019/06/05/challenging-challenges-in-earth-science-research-at-the-egu-general-assembly/. This short course lives by your input! You can contribute by i) stating a research idea or challenge you would like to share, now, and ii) by participating in the discussion during the short course at the EGU 2020. To organize and prepare the discussions, please send a short statement of your idea or challenge related to Earth Science research, and your motivation for solving it (3-4 sentences) to geomorph-problems@geographie.uni-bonn.de, by March 1, 2020. The contributions within the short course are free of charge. If you want to discuss a specific problem, but rather stay anonymous, please let us know. We are all early-career scientists and expect a non-hierarchic, respectful and constructive environment for the discussions, which will hopefully go some way to identifying and engaging with problems which face ECS geomorphologists.

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Co-organized by BG6/CR8/GM14
Convener: Anne VoigtländerECSECS | Co-conveners: Johannes BuckelECSECS, Stefanie TofeldeECSECS, Renee van DongenECSECS, Madeleine HannECSECS
Wed, 06 May, 14:00–15:45
SC1.11

Data generation and processing requirements in the physical sciences are growing rapidly, putting pressure not only on computing resources but also scientists’ capabilities for working with these data. Scientists increasingly need software that is open-source, easy to use and scalable for both distributed and high-performance computing. This course is organised in two mostly independent sessions of 1 hour 45 minutes each. It is open to all and is intended for both experienced and inexperienced programmers. Participants will follow along using Jupyter notebooks to interact with xarray running either on their laptops or in their web browser.

Tutorial website: https://github.com/pangeo-data/pangeo-tutorial/tree/egu2020

# Time block 1: “An introduction to xarray”

This tutorial introduces the software “xarray”, a package developed specifically with the physical sciences in mind but applicable to any multi-dimensional datasets. In this course, we will introduce and demonstrate: the benefits of using Python and its key data-wrangling libraries, pandas and xarray, when working with climate and geoscientific data; working with large, multi-dimensional, labeled datasets in memory and via netCDF; common data operations including indexing, selecting, groupby, and plotting; how to use dask to analyse data too large to fit in memory. We will work with real gridded climate model data and show how the ease of Python+xarray with Jupyter notebooks has been used to teach climate science to students with little programming experience.

# Time block 2: “Scalable geoscience with pangeo”

In this second block, we demonstrate how xarray’s capabilities for out-of-core, out-of-memory and parallel computations can be used to work on datasets up to petabytes in size. Building upon an established software ecosystem (xarray, Dask, Jupyter), Pangeo is a rapidly growing community helping geoscientists perform interactive analysis on such datasets, available either in the cloud or on HPC. In this interactive tutorial we will demonstrate how to employ this platform using real science examples from climatology, physical oceanography, hydrology and geomorphology. We assume some previous experience with xarray, at the level participants will obtain during the first time block.

These blocks build on a previous, similarly-titled version of the course which occurred at EGU2017 and was attended by over 100 people. Course materials will be available to download so bring your laptop!

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Co-organized by AS6/CL6/CR8/GM14/NP9
Convener: Fabien MaussionECSECS | Co-conveners: Benoit BovyECSECS, Edward A. ByersECSECS, Joseph HammanECSECS, Willi RathECSECS
Thu, 07 May, 08:30–12:30