Inter- and Transdisciplinary Sessions
Disciplinary sessions AS–GM
Disciplinary sessions GMPV–TS

Session programme


CL – Climate: Past, Present, Future

CL4 – Past, Present & Future Climates


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

Co-organized by CL4/CR7/OS1
Convener: Niklas BoersECSECS | Co-conveners: Peter Ditlevsen, Timothy Lenton , Anna von der Heydt, Ricarda Winkelmann
| Attendance Wed, 06 May, 08:30–12:30 (CEST)

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.

Co-organized by AS4/CR7/NP3/OS1
Convener: Julia Hargreaves | Co-conveners: Kira Rehfeld, Thomas Laepple, Shaun Lovejoy
| Attendance Fri, 08 May, 14:00–15:45 (CEST)

Modelling paleoclimate states and the transitions between them represents a challenge for models of all complexities. At the same time, the past offers a unique possibility to thoroughly test and evaluate models that are used to simulate the present and make future climate projections.
We invite papers on paleoclimate model simulations, including time-slice (as in the Paleoclimate Modelling Intercomparison Project - PMIP) and transient simulations of climate variations on timescales ranging from millennial to glacial cycles and beyond. Presentations about results from the latest phase of PMIP4-CMIP6 are particularly encouraged. However, comparisons of different models (comprehensive GCMs, EMICs and/or conceptual models), between different periods, and between models and data, including an analysis of the underlying mechanisms, are all within the scope of the session.

Convener: Masa Kageyama | Co-conveners: André Paul, Julia Hargreaves, Michal Kucera
| Attendance Wed, 06 May, 16:15–18:00 (CEST)

Directly observable relative sea-level (RSL) indicators (e.g. shore platforms, coral reef terraces, beach deposits, etc.) are used to constrain paleo sea levels and ice sheet extents and to improve GIA models and future projections of sea-level and ice-sheet responses. Biological proxies associated with and the physical characteristics of RSL indicators can be used to infer paleoclimate and together help inform climatic change and sea-level fluctuations throughout the Pleistocene. The preservation and distribution of these records assists in understanding regional earth surface processes following their deposition.

Recent advances in sea-level studies have called for increased spatiotemporal density of RSL indicators, including submerged and near-field localities, analyzed using standard definitions and methods. This session welcomes contributions to the global record of well-constrained Pleistocene sea-level indicators and associated proxies from a variety of coastal environments, not limited to peak interglacial periods. Re-interpretations of previously described records due to advancement in methods are also welcome.

This session falls within the purview of PALSEA (PALeo constraints on SEA level rise), a PAGES-INQUA Working Group, and the ERC-funded projects, WARMCOASTS and RISeR.

Public information:
The live chat session will be structured to allow abstract authors, who have uploaded display materials, a specific time slot to chat about their research. Four authors will not be presenting their abstracts. Two of them, Jennifer Walker and Andrei Briceag, have uploaded displays and you are encouraged to initiate chat with them through the abstract link.

The final timetable for the session is below. Time is included for general discussion at the end of the session.

Introduction 8:30-8:34
Martina Conti 8:35-8:44
Gino de Gelder 8:45-8:54
Ciro Cerrone 8:55-9:04
Kim Cohen 9:05-9:14
Patrick Boyden 9:15-9:24
Alessio Rovere 9:25-9:34
Teresa Bardaji 9:35-9:44
Carlos Melo 9:45-9:54
Natasha Barlow 9:55-10:04
General Discussion 10:05-10:15

Co-organized by CL4/GM6
Convener: Deirdre RyanECSECS | Co-conveners: Victor CartelleECSECS, Kim Cohen, Alessio Rovere
| Attendance Wed, 06 May, 08:30–10:15 (CEST)

To address societal concerns over rising sea level and extreme events, understanding the contributions behind these changes is key to predict potential impacts of sea level change on coastal communities and global economy, and is recognized as one of the Grand Challenges of our time by the World Climate Research Programme (WCRP). To continue this discussion, we welcome contributions from the international sea level community that improve our knowledge of the past and present changes in sea level, extreme events, and flooding, and produce improved predictions of their future changes. We welcome studies on various drivers of sea level change and linkages between variability in sea level, heat and freshwater content, ocean dynamics, land subsidence from natural versus anthropogenic influences, and mass exchange between the land and the ocean associated with ice sheet and glacier mass loss and changes in the terrestrial water storage. Studies focusing on future sea level changes are also encouraged, as well as those discussing potential short-, medium-, and long-term impacts on coastal and deltaic environments, as well as the global oceans.

Public information:
[allowing for ~5 minutes per display]

8.30-8.32 Introduction to session

8.33-8.40 Invited talk
Kiko Calafat - Probabilistic reanalysis of storm surge extremes in Europe

8.40-9.15 Projections
Aslak Grinsted - The transient sensitivity of sea level rise
Ben Horton - Estimating global mean sea-level rise and its uncertainties by 2100 and 2300 from expert assessment
Erwin Lambert - The codependence of contributors to regional sea-level rise
Lin Wang - Sea Level Rise in Macau and Adjacent Southern China Coast: Historical Change and Future Projections
Rene van Westen - Resolution Dependency of Future Caribbean Sea Level Response
Svetlana Jevrejeva - Developing future sea level services for Small Island Developing States
Alex Todd - Ocean-only FAFMIP: Understanding Regional Patterns of Ocean Heat Content and Dynamic Sea Level Change

9.15-9.50 Observations
Ole Andersen - Consolidating Sea Level Acceleration Estimates from Altimetry for the 1991-2019 Period
Riccardo Riva - Detecting non-linear sea-level variations in tide gauge records: a study case along the Dutch coast
Andrew Matthews - An International Data Centre for GNSS Interferometric Reflectometry Data for Observing Sea Level Change
Francesco de Biasio - Estimating Vertical Land Motion in Northern Adriatic Sea with Coastal Altimetry and In Situ Observations
Marta Marcos - Historical tide-gauge sea-level observations in Alicante and Santander (Spain) since the 19th century
Steve Nerem - Observed Regional Sea Level Trends: Climate Drivers and Implications for Projecting Future Change
Eduardo Zorita - Decadal Sea level Variability in the subtropical South Pacific

9.50-10.15 Sea Level Budget
Martin Horwath - Data products from the ESA CCI Sea Level Budget Closure project
Thomas Frederikse - The causes of sea-level rise since 1900
Bramha Vishwakarma - A revised sea level budget equation to accurately represent physical processes driving sea level rise
Carolina Camargo - Revisiting the Global and Regional Steric Sea-level Trends in the Satellite Era
Bernd Uebbing - Closing the global and regional sea level budgets by combining multi-mission altimetry and GRACE(-FO) data

10.15 Closing the session

The following talks will not be presented during the chat:

*Birgit Hünicke - Statistical Downscaling of daily extreme Sea Level with Random Forest: Examples from South-East Asia and the Baltic Sea
*Tong Lee - Deciphering forcing mechanisms for dynamic sea level variations off the northeast US coast
*Kwang-Young Jeong - Reproduction and projection of sea level around Korean Peninsula using regional climate ocean model with dynamical downscaling method
*Dewi Le Bars - The future of sea level: More knowledge, more uncertainty

Convener: Svetlana Jevrejeva | Co-conveners: Mélanie Becker, Marta Marcos, Aimée Slangen, Nadya Vinogradova Shiffer
| Attendance Mon, 04 May, 08:30–10:15 (CEST)

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).

Public information:
There will be a chat during our session giving each presenter about 5 min. to answer questions.
The schedule is divided into more ISMASS and ISMIP6 related topics and will follow the following time line (which is fluently adapted if presenters are not present):
14:00 - 14:05 Introduction to the chat
14:05 - 14:10 D2555 Ben Galton-Fenzi - Progress towards coupling ice sheet and ocean models
14:10 - 14:15 D2566 Petra Langebroek - Tipping Points in Antarctic Climate Components (TiPACCs)
14:15 - 14:20 D2572 Nadine Wieters - Modular AWI-CM: An Earth System Model (ESM) prototype using the esm-interface library for a modular ESM coupling approach
14:20 - 14:25 D2558 Jon Bamber - Interpretation and Analysis of Projected Ice Sheet Contributions from a Structured Expert Judgement
14:25 - 14:30 D2557 Andrew Shepherd - Trends and projections in ice sheet mass balance
14:30 - 14:35 D2562 Yijing Lin - Antarctic Ice Sheet mass balance over the past decade from 2005 to 2016
14:35 - 14:40 D2569 Johanna Beckmann - How will the Greenland Ice Sheet develop under Extreme Melt Events?
14:40 - 14:45 D2565 Leo van Kampenhout - A regional atmospheric warming threshold for irreversible Greenland ice sheet mass loss
14:45 - 14:50 D2561 Christiaan van Dalum - Evaluation of a new snow albedo scheme in RACMO2 for the Greenland ice sheet
14:50 - 14:55 D2553 Charlotte Lang - Comparison of the surface mass and energy balance of CESM and MAR forced by CESM over Greenland: present and future
14:55 - 15:00 D2554 Nanna Bjørnholt Karlsson - Basal Melt of the Greenland Ice Sheet: The Invisible Mass Budget Term
15:00 - 15:05 D2551 Heiko Goelzer - The future sea-level contribution of the Greenland ice sheet: a multi-model ensemble study of ISMIP6
15:05 - 15:10 D2560 Tony Payne - Contrasting contributions to future sea level under CMIP5 and CMIP6 scenarios from the Greenland and Antarctic ice sheets
15:10 - 15:15 D2552 Tamsin Edwards - Quantifying uncertainties in the land ice contribution to sea level from ISMIP6 and GlacierMIP
15:15 - 15:20 D2568 Helene Seroussi - ISMIP6 Antarctica: a multi-model ensemble of the Antarctic ice sheet evolution over the 21st century
15:20 - 15:25 D2571 Martin Rückamp - Sensitivity of Greenland ice sheet projections to spatial resolution in higher-order simulations: the AWI contribution to ISMIP6-Greenland using ISSM
15:25 - 15:30 D2573 Thomas Kleiner - ISMIP6 Future Projections for Antarctica performed using the AWI PISM ice sheet model
15:30 - 15:35 D2570 Konstanze Haubner - Changes on Totten glacier dependent on oceanic forcing based on ISMIP6
15:35 - 15:40 D2556 Ronja Reese - The role of history and strength of the oceanic forcing in sea-level projections from Antarctica with the Parallel Ice Sheet Model

note: ISMASS and ISMIP6 homepages have been moved and are now available here:

Co-organized by CL4/OS1, co-sponsored by CliC
Convener: Frank Pattyn | Co-conveners: Konstanze HaubnerECSECS, Guðfinna Aðalgeirsdóttir, Helene Seroussi, Donald SlaterECSECS
| Attendance Thu, 07 May, 14:00–15:45 (CEST)

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.

Public information:
We have decided to organise the chat in two parts:

1. During the first part we will go through the existing displays in order and have 5 minutes for each to answer questions from the participants.
Preliminary schedule below. Since we don't know yet the final number of displays available this timing may still change.

10:45 Intro
10:50 D2558 EGU2020-15058 Did a Beringian ice sheet once exist?
10:55 D2559 EGU2020-5912 Global coupled climate - ice sheet model simulations for the penultimate deglaciation and the last interglacial
11:00 D2561 EGU2020-7844 Impact of mid-glacial ice sheets on the recovery time of the AMOC: Implications on the frequent DO cycles during the mid-glacial period
11:05 D2562 EGU2020-18683 Modelling the surface mass balance of the Greenland Ice Sheet from 6000 BP to the year 2200
11:10 D2563 EGU2020-10601 Greenland ice sheet contribution to 21st century sea level rise as modelled by the coupled CESM2.1-CISM2.1
11:15 D2564 EGU2020-20368 The North Atlantic Oscillation and the Greenland ice sheet in CMIP6
11:20 D2566 EGU2020-5647 A circumpolar coupled ocean – Antarctic ice sheet configuration for investigating recent changes in Southern Ocean heat content
11:25 D2567 EGU2020-2272 Transient Pleistocene simulations with a new coupled climate-ice-sheet model
11:30 D2568 EGU2020-16221 Comparison of peri-Antarctic sub-shelf melt rates in coupled and uncoupled ice-sheet model simulations
11:35 D2570 EGU2020-10255 Coupling the Parallel Ice Sheet Model with the Modular Ocean Model via an Antarctic ice-shelf cavity module
11:40 D2572 EGU2020-11625 AMOC recovery in a multi-centennial scenario using a coupled atmosphere-ocean-ice sheet model
11:45 D2574 EGU2020-21261 The ocean response to changes of the Greenland Ice sheet in a warming climate
11:50 D2577 EGU2020-16815 Dynamic Hydrological Discharge and Lake Modelling for Coupled Climate Model Simulations of the Last Glacial Cycle
11:55 D2578 EGU2020-21686 Greenland ice sheet surface mass balance response to high CO2 forcing: threshold and mechanisms for accelerated surface mass loss
12:00 D2579 EGU2020-17514 A global ensemble-based comparison of the last two glacial inceptions with LCice 2.0

2. Time permitting, we were hoping to discuss a few key questions as an open chat with everybody (authors and participants) around the theme of our session: Ice-sheet and climate interactions. Of course, these discussions are just a starter and we encourage everyone to keep communicating and discussing via other media after the session.

Some examples:

- What is the most important progress in ice sheet-climate model
coupling in the last 5 years? (distinguish paleo and future perspective).

- What model improvement is necessary to address outstanding scientific

- Where do you see important gaps in our knowledge that should be addressed?

- What observational data has had an important impact on our
understanding of ice sheet-climate interactions?

- What paleo archives (kind, location, time frame) would be the most
important to examine/extend to improve our knowledge about ice
sheet-climate interactions?

Please remember that the chat will not be preserved. Comments and questions on individual displays (that have not been answered) are best posted in the online discussion under the display abstracts. Public discussion and feedback of presentation materials is open to 31 May.

Co-organized by CL4
Convener: Heiko Goelzer | Co-conveners: Alexander Robinson, Ricarda Winkelmann, Philippe Huybrechts, Stefanie MackECSECS
| Attendance Wed, 06 May, 10:45–12:30 (CEST)

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.

Public information:
We will allocate five minutes of text-based discussion time to each abstract, as follows:

10:45-10:50 Introduction
10:50-10:55 Eelco Rohling
10:55-11:00 Jim Jordan
11:00-11:05 Javier Blasco
11:05-11:10 Emily Hill
11:10-11:15 Felicity McCormack
11:15-11:20 Gordon Bromley
11:20-11:25 Christian Turney
11:25-11:30 Tyler Pelle
11:30-11:35 Liyun Dai
11:35-11:40 Jun-Young Park
11:40-11:45 Christian Ohneiser
11:45-11:50 Catherine Beltran
11:50-11:55 Johannes Sutter
11:55-12:00 Nicolas Ghilain
12:00-12:05 Torsten Albrecht
12:05-12:10 Nicolas Jourdain
12:10-12:15 Christoph Kittel
12:15-12:20 Caroline van Calcar
12:20-12:25 James O'Neill
12:25-12:30 Thore Kausch

Co-organized by CL4/G3/OS1
Convener: Steven Phipps | Co-conveners: Florence Colleoni, Chris Fogwill, Taryn Noble
| Attendance Tue, 05 May, 10:45–12:30 (CEST)

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.

Co-organized by CL4/OS1
Convener: Christine BatchelorECSECS | Co-conveners: Kiya RivermanECSECS, Frazer ChristieECSECS, Katherine HutchinsonECSECS, David Vaughan
| Attendance Wed, 06 May, 14:00–15:45 (CEST)

The large-scale atmospheric circulation strongly influences Earth's climate, both locally and globally, via its transport of energy, moisture, and momentum. While our ability to simulate the global circulation is improving, large model biases and uncertainties in climate change projections persist. Our theoretical understanding of how atmospheric circulations respond to climate changes is also limited, particularly on regional scales and in the presence of zonal asymmetries. Advancing our knowledge of the underlying dynamics is therefore crucial for reliable climate projections and for correctly interpreting palaeoclimate records.

The objective of this session is to advance our mechanistic understanding of atmospheric circulation changes and to analyse their impacts at global and regional scales, specifically on precipitation in past, present, and future climates. We encourage theoretical, observational and modelling contributions on tropical (ITCZ, monsoons, Hadley & Walker circulations, MJO) and extratropical circulations (jet streams, storm tracks, blocking).

Co-organized by AS1
Convener: Michael ByrneECSECS | Co-conveners: Thomas Birner, Nicholas LutskoECSECS, Max Popp, Talia TamarinECSECS
| Attendance Thu, 07 May, 08:30–12:30 (CEST)

Regional climate modeling has become an established and grwoing area of research in the last decades. Regional Climate Models (RCMs) are powerful and flexible tools which can be used for a wide variety of problems at regional scales, from the study of regional processes and the interactions between atmosphere, biosphere and chemosphere/aerosols to paleoclimate simulations and future climate projections. The resolution of RCMs varies from a few tens of km to convection-permitting scales (a few km) and the length of simulation has reached the multi-centennial scales. Different RCM intercomparison projects have been crried out in the past, culminating in the Coordinated Regional Downscaling EXperiment (CORDEX), an international program aimed at better understanding and improving regional downscaling techniques and producing large ensembles of projections for domains worldwide. The results from CORDEX and other RCM initiative have been extensively used for impact applications and provide the basis for many climate service activities. Following a tradition of very successful and well attended EGU sessions in the past, this session accepts frontier papers on all aspects of regional climate modeling science and application, and on the latest results from the CORDEX project.

Convener: Filippo Giorgi | Co-conveners: Melissa Bukovsky, Ivan Guettler
| Attendance Mon, 04 May, 10:45–12:30 (CEST), Attendance Mon, 04 May, 14:00–15:45 (CEST)

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.

Co-organized by AS4/CR7
Convener: Richard Bintanja | Co-convener: Rune Grand Graversen
| Attendance Tue, 05 May, 16:15–18:00 (CEST)

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.

Public information:
Dear participants in EGU 2020 session CL4.14,

Thanks you all for your various contributions to this session and for participating in the live chat. As this is a new form, we probably all wonder how well it will work, but we are also excited about trying out this new way of discussing our science!
None of the co-conveners have any experience in chats – and not the least managing them, so please accept our apologies if not everything will go as smoothly as we will like.

Process for the chat session:
Hopefully, you have all succeeded in uploading any display that you wish. However, also those who have chosen not to add any further material will still have the option to discuss your research based on your abstracts and any addition information that you can tell us.
Note: This chat is not recorded or stored. Only abstracts and further displays will be available after this session. This provides more freedom to discuss.
Also: All discussion will be in writing via the chat.
To best organize the chat session, we will carry out the chat for one presentation (display) at the time.
We (the conveners) will start up by writing the number of the display in the chat and invite the presenter to give a short introduction. Presenter: It would be advisable if you have a short text ready that you can upload in the chat box. Do not expect to give a full presentation, just give a SHORT introduction and highlight the main points. So, make it short, as we have many displays and people need time to read the chat messages. Do not just copy the entire abstract, as all session participants have had the possibility to read these prior to the chat session

After this short introduction to the presentation, the floor is now open for comments.
If no comments arrive within 30 seconds to 1 minute, we will move to the next display. Also, if no presenter is present for a display, we will also move on to the next display. One minute is a short time to write a detailed question, so it could be a good idea to prepare some comments beforehand.

Timing: We have up to 1h45min available for the session. With 27 presentations, this gives 3-4 minutes for each presentation. We did not succeed in getting a full overview of, who among the presenters, would like to discuss their result. Thus, currently we do not know how many presenters will be present or how much discussion each presentation will cause. Therefore, we need to keep a tight schedule but we will still try to be flexible, if there is a lively discussion. As there are some among the conveners who have indicated that they will likely not join the session, there should be some additional time, which at the first instance will be allocated to those, who have uploaded material in addition to abstracts – you will get 5 min for the discussion. Should there be time in the end after the full round of presentations/discussions, we can always return to discuss.

The chat session ends either when our time runs out or if the discussion ends.

All the best and keep safe,
Marit-Solveig Seidenkrantz, Anne de Vernal, Michal Kucera, Mimmi Oksman & Henrieka Detlef

Co-organized by CR7/OS1
Convener: Marit-Solveig Seidenkrantz | Co-conveners: Anne de Vernal, Michal Kucera, Mimmi OksmanECSECS, Henrieka Detlef
| Attendance Mon, 04 May, 16:15–18:00 (CEST)

The Arctic sea ice and high latitude atmosphere and oceans have experienced significant changes over the modern observational era. The polar climate is crucial for the Earth’s energy and water budget, and its variability and change have direct socio-economic and ecological impacts. Thus, understanding high-latitude variability and improving predictions of high latitude climate is highly important for society. Predictability studies indicate that decadal to multi-decadal variations in the oceans and sub-seasonal to multi-year sea ice variations are the largest sources of predictability in high latitudes. However, dynamical model predictions are not yet in the position to provide us with accurate predictions of the polar climate. Main reasons for this are the lack of observations in high latitudes, insufficient initialization methods and shortcomings of climate models in representing some of the important climate processes in high latitudes.
This session aims for a better understanding and better representation of the mechanisms that control high latitude variability and predictability of climate in both hemispheres from sub-seasonal to multi-decadal time-scales in past, recent and future climates. Further, the session aims to discuss ongoing efforts to improve climate predictions at high latitudes at various time scales (as e.g. usage of additional observations for initialization, improved initialization methods, impact of higher resolution, improved parameterizations) and potential teleconnections of high latitude climate with lower latitude climate. We also aim to link polar climate variability and predictions to potential ecological and socio-economic impacts and encourage submissions on this topic.
The session offers the possibility to present results from the ongoing projects and research efforts on the topic of high-latitude climate variability and prediction, including, but not limited to the WWRP Year of Polar Prediction (YOPP), NordForsk-project ARCPATH, and the H2020-projects APPLICATE, INTAROS, BlueAction, and PRIMAVERA.

Co-organized by AS4/OS1
Convener: Torben Koenigk | Co-conveners: Neven-Stjepan Fuckar, Yongqi Gao, Helge Goessling
| Attendance Fri, 08 May, 10:45–12:30 (CEST)

The North Pacific’s sensitivity to forcing and feedbacks to background climate are an important, but largely open question in assessments of global climate, both in the modern and geological past. Enhanced knowledge of processes of past climate change is crucial to separate between natural and anthropogenic forcing, and to enhance the reliability of future climate projections. On a spatial scale, this region also comprises major oceanographic patterns including Boundary Current systems e.g., Kuroshio/Oyashio, or the Alaskan Stream and several frontal regions. In addition, complex exchange processes and interactions between the open North Pacific and its marginal seas from low to high latitudes create a spatially heterogenous region, with small-scale mixing and both temporal and spatial variations in the system at atmospheric, and oceanic surface, subsurface and deep levels.
We aim to provide a comprehensive collection of original contributions and syntheses that foster the dynamic and four-dimensional understanding of the evolution of climate and oceanic modes in the North Pacific, including links and teleconnections to low latitudes (e.g. West Pacific Warm Pool) and polar regions, as well as to global ocean circulation and climate patterns.
We welcome contributions across all time scales, from the geological past to present. Results may be based on instrumental or proxy data, as well as climate modelling. The session should advance our process-oriented understanding of the complex role of the North Pacific and its marginals seas in regulating biogeochemical cycles, ocean overturning circulation, and ocean-atmosphere carbon budgets. These past climate scenarios can be used to create a framework for the identification of potential thresholds in the current, warming Earth system.

Co-organized by OS1
Convener: Xun GongECSECS | Co-conveners: Lester Lembke-JeneECSECS, Gerrit Lohmann, Xuefa Shi
| Attendance Wed, 06 May, 16:15–18:00 (CEST)

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.

Public information:
Online survey (including questions about a possible follow-up webinar): https://form.jotformeu.com/83462227858365

Co-organized by AS1/CR7/NH1
Convener: Wolfgang Schöner | Co-conveners: Carolina Adler, Maria Vittoria Guarino, Elisa Palazzi, Stefano Serafin
| Attendance Mon, 04 May, 14:00–15:45 (CEST)

Meridional flows of heat and moisture are largely driven by global patterns of energy surplus and deficit and sensitive to multiple forcings and feedbacks. The large-scale atmospheric-oceanic circulation and the hydrological cycle are tightly intertwined with such heat and moisture transports.
For example, inter-hemispheric energy asymmetries play an important role in modulating the strength of the Hadley Circulation, which in turn modulates the low-level mass convergence and the amount of precipitation in the ITCZ and in monsoon regions. In the extra-tropics, Rossby waves affect the distribution of precipitation and eddy activity, shaping the meridional heat transport from the low latitudes towards the Poles.
We invite submissions addressing the interplay between Earth’s energy exchanges and the response of the general circulation using modeling approaches, theoretical considerations, and observations.
We also encourage contributions on dynamics, trends, characteristics and past-to-future variability of mean meridional circulation and its impact on regional climate.

Co-organized by AS4
Convener: Roberta D AgostinoECSECS | Co-conveners: Maria Z. HakubaECSECS, David Ferreira, Valerio LemboECSECS, Piero Lionello
| Attendance Fri, 08 May, 16:15–18:00 (CEST)

The interactions between aerosols, climate, and weather are among the large uncertainties of current atmospheric research. Mineral dust is an important natural source of aerosol with significant implications on radiation, cloud microphysics, atmospheric chemistry and the carbon cycle via the fertilization of marine and terrestrial ecosystems.
In addition, properties of dust deposited in sediments and ice cores are important (paleo-)climate indicators.

This interdivision session is open to contributions dealing with:
(1) measurements of all aspects of the dust cycle (emission, transport, deposition, size distribution, particle characteristics) with in situ and remote sensing techniques,
(2) numerical simulations of dust on global and regional scales,
(3) meteorological conditions for dust storms, dust transport and deposition,
(4) interactions of dust with clouds and radiation,
(5) influence of dust on atmospheric chemistry,
(6) fertilization of ecosystems through dust deposition,
(7) any study using dust as a (paleo-)climate indicator including investigations of Loess, ice cores, lake sediments, ocean sediments and dunes.

We especially encourage to submit papers on the integration of different disciplines and/or modeling of past, present and future climates.

Public information:
Please be aware that there are a number (N=3) changes in the order in which the presentations will be discussed. Please have a look at the provided session materials for the final program.

Co-organized by BG1/CL4/GM8/SSP3, co-sponsored by ISAR
Convener: Jan-Berend Stuut | Co-conveners: Paola Formenti, Joanna Nield, Claire Ryder, Mingjin TangECSECS
| Attendance Fri, 08 May, 10:45–12:30 (CEST)

ENSO and its interactions with other tropical basins are the dominant source of interannual climate variability in the tropics and across the globe. Understanding the dynamics, predictability, and impacts of ENSO and tropical basins interactions, and anticipating their future changes are thus of vital importance for society. This session invites contributions regarding all aspects of ENSO and tropical basins interactions, including: dynamics, multi-scale interactions; low frequency, decadal and paleo variability; theoretical approaches; ENSO diversity; global teleconnections; impacts on climate, society and ecosystems; seasonal forecasting and climate change projections of ENSO and its tropical basins interactions. Studies aimed at understanding ENSO and its tropical basins interactions in models of a range of complexity are especially welcomed, including analysis of CMIP model intercomparisons.

Public information:
Dear all,
welcome to the virtual EGU 2020. This is just a reminder that we will have the "ENSO and Tropical Basins Interactions: Dynamics, Predictability and Modelling" (CL4.20/AS1.12/NP2.6/OS1.27) session Thu, 07 May, 14:00–15:45 (Vienna time zone). It will be an online chat only session.

In addition to the EGU chat session on Thursday we plan to do a video meeting for the "ENSO and Tropical Basins Interactions: Dynamics, Predictability and Modelling" session with presentations from the authors (you) some time later this year (e.g. June/July). More on this we will discuss on Thursday in the EGU chat of this session.

Best regards and hope to chat with you on Thursday!
Dietmar Dommenget, Antonietta Capotondi, Daniela Domeisen and Eric Guilyardi

Co-organized by AS1/NP2/OS1
Convener: Dietmar Dommenget | Co-conveners: Antonietta Capotondi, Daniela Domeisen, Eric Guilyardi
| Attendance Thu, 07 May, 14:00–15:45 (CEST)

Land–atmosphere interactions often play a decisive role in shaping climate extremes. As climate change continues to exacerbate the occurrence of extreme events, a key challenge is to unravel how land states regulate the occurrence of droughts, heatwaves, intense precipitation and other extreme events. This session focuses on how natural and managed land surface conditions (e.g., soil moisture, soil temperature, vegetation state, surface albedo, snow or frozen soil) interact with other components of the climate system – via water, heat and carbon exchanges – and how these interactions affect the state and evolution of the atmospheric boundary layer. Moreover, emphasis is placed on the role of these interactions in alleviating or aggravating the occurrence and impacts of extreme events. We welcome studies using field measurements, remote sensing observations, theory and modelling to analyse this interplay under past, present and/or future climates and at scales ranging from local to global but with emphasis on larger scales.

Co-organized by AS2/HS13
Convener: Wim ThieryECSECS | Co-conveners: Gianpaolo Balsamo, Diego G. Miralles, Sonia Seneviratne, Ryan Teuling
| Attendance Tue, 05 May, 14:00–15:45 (CEST)

Adapting to climate change in the Mediterranean region represents a critical socio-economic and environmental challenge. Different levels of exposure and vulnerability as well as different projected changes characterize the Mediterranean region. Understanding the past, characterizing the present and modelling the future are therefore essential steps to estimate the risks, assess the impacts of climate change, and identify potential adaptation and mitigation strategies. This multidisciplinary MedCLIVAR session encourages contributions from a broad range of disciplines and topics, e.g. dealing with: dynamics and processes of the climate system; sectorial impacts of climate change; climate change adaptation and mitigation; innovative methods and approaches in climate science. The session focuses on all time scales from paleoclimate to future model projections as well as on all relevant socio-economic sectors.

Convener: Andrea Toreti | Co-conveners: Ana BastosECSECS, Piero Lionello, Nathalie Combourieu Nebout, Marie-Alexandrine Sicre
| Attendance Wed, 06 May, 08:30–12:30 (CEST)

Documenting the diversity of human responses and adaptations to climate, landscapes, ecosystems, natural disasters and the changing natural resources availability in different regions of our planet, cross-disciplinary studies in human-landscape interaction provide valuable opportunities to learn from the past. This session is targeted at providing a platform for scientists with common interests in geomorphology and geoarchaeology and, in particular, the complex and integrated nature of the relationship between landforms, geomorphological processes and societies during the Anthropocene, and how this has developed over time at different spatial and temporal scales.

This session seeks related interdisciplinary papers and specific geomorphological or geoarchaeological case-studies that deploy various approaches and tools to address the reconstruction of former and present human-environmental interactions from the Palaeolithic period through the modern. Topics related to records of the Anthropocene from Earth and archaeological science perspectives are welcome. We are inviting contributions that focus on the two-way interactions between geomorphological processes/landforms and human activity. These should show how the various factors of the physical environment interact with the Anthroposphere, and, in turn, how population and individuals may affect (and change) these factors. Furthermore, contributions may include (but are not limited to) insights about how people have coped with environmental disasters or abrupt changes; defining sustainability thresholds for farming or resource exploitation; distinguishing the baseline natural and human contributions to environmental changes. In this context, topics of different fields may be addressed in the session such as landform evolution, landscape sensitivity and resilience in the overall context of the interrelation between geomorphology and society, geohazards, geoheritage and conservation, geomorphological responses to (and evidence for) environmental change, and applied geomorphology. Moreover, issues of scale and hierarchies may be addressed, and methods and applications of dynamic rather than equilibrium ideas and metaphors. Ultimately, we would like to understand how strategies of human resilience and innovation can inform our modern strategies for addressing the challenges of the emerging Anthropocene, a time frame dominated by human modulation of surface geomorphological processes and hydroclimate.

Co-organized by BG3/CL4/NH8/SSP1/SSS3
Convener: Julia MeisterECSECS | Co-conveners: André Kirchner, Guido Stefano MarianiECSECS, Kathleen Nicoll, Hans von Suchodoletz, Sanja Faivre, Sven Fuchs, Margreth Keiler
| Attendance Mon, 04 May, 14:00–18:00 (CEST)

The Indian Ocean is unique among the other tropical ocean basins due to the seasonal reversal of monsoon winds and concurrent ocean currents, lack of steady easterlies that result in a relatively deep thermocline along the equator, low-latitude connection to the neighboring Pacific and a lack of northward heat export due to the Asian continent. These characteristics shape the Indian Ocean’s air-sea interactions, as well as its variability on (intra)seasonal, interannual, and decadal timescales. They also make the basin and its surrounding regions, which are home to a third of the global population, particularly vulnerable to anthropogenic climate change: robust trends in heat transport and freshwater fluxes have been observed in recent decades in the Indian Ocean and Maritime Continent region. Advances have recently been made in our understanding of the Indian Ocean’s circulation, interactions with adjacent ocean basins, and its role in regional and global climate. Nonetheless, significant gaps remain in understanding, observing, modeling, and predicting Indian Ocean variability and change across a range of timescales.
This session invites contributions based on observations, modelling, theory, and palaeo proxy reconstructions in the Indian Ocean that focus on understanding recent observed and projected changes in Indian Ocean physical and biogeochemical properties and their impacts on ecological processes, links between Indian Ocean variability and monsoon systems on (intra)seasonal to interannual timescales, interactions and exchanges between the Indian Ocean and other ocean basins, natural decadal variability, and extreme events. Contributions are sought in particular that address research on the Indian Ocean grand challenges highlighted in the recent IndOOS Decadal Review, and as formulated by the Climate and Ocean: Variability, Predictability, and Change (CLIVAR), the Sustained Indian Ocean Biogeochemistry and Ecosystem Research (SIBER), and the International Indian Ocean Expedition 2 (IIOE-2) programs.

Co-organized by BG4/CL4
Convener: Caroline Ummenhofer | Co-conveners: Yan Du, Alejandra Sanchez-FranksECSECS, Jérôme Vialard
| Attendance Thu, 07 May, 08:30–10:15 (CEST)

The Southern Ocean around the latitudes of the Antarctic Circumpolar Current is a key region for the vertical and lateral exchanges of heat, carbon and nutrients, with significant impacts on the climate system as a whole. The role of the Southern Ocean as a sink of anthropogenic carbon and heat, and as a source of natural carbon in present and future climate conditions remains uncertain. To reduce this uncertainty, understanding the physical and biogeochemical processes underlying the Southern Ocean internal variability and its response to external forcing is critical. Recent advances in observational capabilities, theoretical frameworks, and numerical models (e.g. CMIP6 simulations) are providing a deeper insight into the three-dimensional patterns of Southern Ocean change. This session will discuss the current state of knowledge and novel findings concerning the role of the Southern Ocean in past, present, and future climates. In particular, it will address physical, biological, and biogeochemical processes, including interior ocean mixing and transport pathways, the cycling of carbon and nutrients, as well as ocean-ice-atmosphere interactions, and their wider implications for lower latitudes and the global climate.

Highlight: Solicited speaker Michael Meredith will report on the outcomes of the Polar Regions chapter of the recent "IPCC Special Report on the Ocean and Cryosphere in a Changing Climate" during this session.

Public information:
Please join our live text chat on the display items. The displays will be discussed in the order outlined in our program: https://tinyurl.com/y88p7g5o

There will be a joined virtual (video) coffee break (15:45-16:15 CEST) between sessions OS1.12 and OS1.13 as well as a follow-up online open bar (18:00- CEST). Please join us. You can find a registration link in the session program.

Co-organized by BG4/CL4
Convener: Alexander HaumannECSECS | Co-conveners: Ivy FrengerECSECS, Lavinia Patara, Christian Turney
| Attendance Thu, 07 May, 14:00–15:45 (CEST)

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.

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
| Attendance Thu, 07 May, 16:15–18:00 (CEST)

The dynamics of the solid Earth and its surface are strongly affected by their interplays as well as biota and climate. These constant feedback systems operate at a variety of spatial and temporal scales that are regulated in a complex system of interactions. For instance, in the critical zone -the terrestrial surface environment ranging from the lower atmosphere to the solid parent material- interplays not only regulate manifold ecosystems and bio-geochemical cycles, but also shape the Earth’s surface at the interface between atmosphere and lithosphere, where soils develop. At much larger scales, plate tectonics and global geodynamics control the physiography, climate and hydrosphere, which in turn strongly affect the surface feedback processes via tectonic, biological, geochemical and hydrological processes. Ultimately, climate and tectonics are prominent macro-ecological drivers of landscape development. But even though the underlying geology and tectonic processes have long been recognized as driving parameters, this is much less so for biological processes. The driving force of microorganisms, plants and animals on the shape of land surfaces is still poorly understood.
Understanding the links between the solid Earth and the external spheres of the Earth has experienced a recent upswing due to advanced analytical techniques, but also thanks to fostered interactions between researchers from different disciplines. This session aims to bring together geoscientists, soil scientists, climatologists and biologists working at different spatial and temporal scales on the feedback interactions between geology, topography, soils, climate and biosphere at the surface of the Earth. The session covers a multitude of topics from the microbial to the geodynamics time and space scales.

Solicited speakers are:
Carina Hoorn, University of Amsterdam, The Netherlands
Alexia Stokes, French National Institute for Agricultural Research – INRA, France
Veerle Vanacker, University of Louvain, Belgium

Co-organized by BG1/CL4/GD1/GM4/SSP2
Convener: Steffen SeitzECSECS | Co-conveners: Laurent Husson, Annegret LarsenECSECS, Carsten W. Mueller, Pierre Sepulchre, Kirstin ÜbernickelECSECS
| Attendance Fri, 08 May, 08:30–10:15 (CEST)

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

Co-organized by CL4/CR4
Convener: Andreas Kellerer-Pirklbauer | Co-conveners: Natacha Gribenski, Isabelle Gärtner-Roer, Sven Lukas
| Attendance Thu, 07 May, 08:30–10:15 (CEST)

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

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

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

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

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
| Attendance Fri, 08 May, 08:30–10:15 (CEST)

The Amazon forest is the world’s largest intact forest landscape. Due to its large biodiversity, carbon storage capacity, and role in the hydrological cycle, it is an extraordinary interdisciplinary natural laboratory of global significance. In the Amazon rain forest biome, it is possible to study atmospheric composition and processes, biogeochemical cycling and energy fluxes at the geo-, bio-, atmosphere interface under near-pristine conditions for a part of the year, and under anthropogenic disturbance of varying intensity the rest of the year. Understanding its current functioning at process up to biome level in its pristine and degraded state is elemental for predicting its response upon changing climate and land use, and the impact this will have on local up to global scale.
This session aims at bringing together scientists who investigate the functioning of the Amazon and comparable forest landscapes across spatial and temporal scales by means of remote and in-situ observational, modelling, and theoretical studies. Particularly welcome are also presentations of novel, interdisciplinary approaches and techniques that bear the potential of paving the way for a paradigm shift.

Co-organized by AS4/CL4/HS12
Convener: Jošt Valentin Lavrič | Co-conveners: Alessandro Araujo, Carlos Alberto Quesada, Matthias Sörgel
| Attendance Fri, 08 May, 10:45–12:30 (CEST)

Many water management sectors are already having to cope with extreme weather events, climate variability and change. In this context, predictions on sub-seasonal, seasonal to decadal timescales (i.e. horizons ranging from months to a decade) are an emerging and essential part of hydrological forecasting. By providing science-based and user-specific information on potential impacts of extreme events, operational hydro-meteorological services are invaluable to a range of water sectors such as transport, energy, agriculture, forestry, health, insurance, tourism and infrastructure.

This session aims to cover the advances in climate and hydro-meteorological forecasting, and their implications on forecasting extreme events for improved water management. It welcomes, without being restricted to, presentations on:

- Making use of climate data for hydrological modelling (downscaling, bias correction, temporal disaggregation, spatial interpolation and other technical challenges),
- Methods to improve forecasting of hydrological extremes,
- Improved representations of hydrological extremes in a future climate,
- Seamless forecasting, including downscaling and statistical post- and pre-processing,
- Propagation of climate model uncertainty to hydrological models and impact assessment,
- Lessons learnt from forecasting and managing present day extreme conditions,
- Operational hydro-meteorological (sub-seasonal to decadal) forecasting systems and climate services,
- Effective methods to link stakeholder interests and scientific expertise (e.g. service co-generation).

The session will bring together research scientists and operational managers in the fields of hydrology, meteorology and climate, with the aim of sharing experiences and initiating discussions on this emerging topic. We encourage presentations from initiatives such as the H2020 IMPREX, BINGO, S2S4E and CLARA projects, and from WWRP/WCRP S2S projects that utilise the recently established S2S project database, and all hydrological relevant applications.

Public information:
Welcome to HS4.6 at #shareEGU20!

This session aims to cover the advances in climate and hydro-meteorological forecasting, and their implications on forecasting extreme events for improved water management. We thank the authors for their valuable contributions to this session. We have a range of brilliant displays, which cover a range of forecast lead times, case study areas and applications.

The displays for the session have been grouped into two categories: Research Studies and Operational & Applied Studies, with each display having a 5 min slot for discussion.

We will start the session at 10:45 CET on Thursday 07 May. The display times listed below may change a bit last minute, but this is the schedule we will try to stick to.

We hope you will enjoy the session!
--- HS4.6 session co-conveners


10:45-10:50 CET
Welcome and opening remarks

Research Studies:

D252: EGU2020-17646 - Spatial and temporal patterns in seasonal forecast skill based on river flow persistence in Irish catchments
Daire Quinn et al.

D253: EGU2020-9149 - Seasonal streamflow forecasting - Which are the drivers controlling the forecast quality?
Ilias Pechlivanidis et al.

D254: EGU2020-18796 - Sensitivity of seasonal hydrological predictability sources to catchment properties
Maria Stergiadi et al.

D255: EGU2020-1533 - Analysis and prediction of hydrological extreme conditions for a small headwater catchment in a German lower mountain range
Lisa Hennig et al.

D257: EGU2020-9321 - Sensitivity analysis of MOHID-Land model. Calibration and validation of Ulla river watershed.
Ana Oliveira et al.

D260: EGU2020-2167 - Modelling runoff generation of a small catchment in the context of climate change by using an ensemble of different climate model outputs and bias correction methods
Kai Sonntag et al.

Open discussion and short break (if time allows)

Operational & Applied Studies:

D261: EGU2020-9773 - A Real-time Ensemble Hydrological Forecasting System over Germany at Sub-seasonal to Seasonal Time Range
Husain Najafi et al.

D262: EGU2020-20290 - Towards improved disaster preparedness and climate proofing in semi-arid regions: development of an operational seasonal forecasting system
Christof Lorenz et al.

D263: EGU2020-5494 - Using seasonal forecast for energy production: SHYMAT climate service, a small hydropower management and assessment tool
Eva Contreras Arribas et al.

D264: EGU2020-5550 - How seasonal forecast can improve the water planning in multipurpose reservoirs: ROAT climate service, a reservoir operation assessment tool
Javier Herrero Lantarón et al.

D265: EGU2020-15853 - SMHI Aqua: a new co-generated hydro-climate service to enable sustainable freshwater management
Carolina Cantone et al.

D266: EGU2020-9006 - Using seasonal forecast information to strengthen resilience and improve food security in Niger River Basin
Bernard Minoungou et al.

Open discussion and HS4.6 closing remarks

Co-organized by CL4
Convener: Christopher White | Co-conveners: Louise ArnalECSECS, Tim aus der Beek, Louise CrochemoreECSECS, Andrew SchepenECSECS
| Attendance Thu, 07 May, 10:45–12:30 (CEST)

Comprehensive studies to address ocean science issues require synergistic collaboration across the globe between many subdisciplines including science, engineering, environment, society and economics. However, it is a challenge to unify these aspects under a common program or study, and as such has been recognized as a main goal of the United Nations “Decade of Ocean Science for Sustainable Development (2021-2030)”. Consequently, this session will bring together early-career representatives from a wide range of subdisciplines to demonstrate the strength of an interdisciplinary and intercultural approach when addressing global concerns, such as the dynamic impacts of climate change, focusing on the North Atlantic region as an example.

Continuous and comprehensive data is crucial to our understanding of the ocean. Yet, developing the advanced tools and technologies required for long-term ocean monitoring is not merely an engineering problem, as the data produced by these instruments will have future environmental and socio-economic impacts. A comprehensive view of the ocean also requires an understanding of past conditions. Thus, this session will also include contributions from paleo-oceanography to link the past to the future. In this vein, we will discuss our attempts at transdisciplinary and transcultural collaboration and share what we have learned for future approaches.

We invite contributions from a wide range of enthusiasts, including those in the natural sciences (e.g. biology, physics), applied sciences (e.g. engineering and technology, business), humanities (e.g. law), and social sciences (e.g. economics, political science). We also invite contributions from educators and administrators who are interested in experimenting with novel methods of building and encouraging research within interdisciplinary and multicultural graduate school programs.

Co-organized by EOS4/CL4
Convener: Allison ChuaECSECS | Co-conveners: Jacqueline BertlichECSECS, Kriste Makareviciute-FichtnerECSECS, Subhadeep RakshitECSECS
| Attendance Mon, 04 May, 14:00–15:45 (CEST)

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.


Public information:
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.


Co-organized by EOS4/CL4/CR7/GM7
Convener: Carolina Adler | Co-convener: Aino Kulonen
| Attendance Mon, 04 May, 14:00–15:45 (CEST)

Volcanic emission can have a strong impact on the Earth’s radiation budget and climate over a range of temporal and spatial scales, depending on the activity type (passive degassing and small magnitude to strong explosive eruptions).
It is now well known that strong explosive volcanic eruptions are a major natural driver of climate variability at interannual to multidecadal time scales. Assessment of volcanically-forced climate variability is complicated by many limiting factors, including the paucity of observed eruptions, uncertainties in volcanic forcing datasets for the current and pre-instrumental periods, limitations of proxy-based climate evidence, uncertainties of global aerosol model simulations and the apparent large inconsistencies in the responses to volcanic forcing simulated by current climate models. Quiescent passive degassing and smaller-magnitude eruptions on the other hand can impact on regional climate system. In addition, volcanic emissions may influence local-to-regional air quality, seriously affect the biosphere and environment, and the release of gas from soil may pose long-term health hazards. This session focuses on new results from integrative research on the climatic, environmental and societal impacts of the volcanic activity, including eruptions of Pinatubo-magnitude and larger, volcanic degassing and small eruptions.

We aim to highlight contributions conducted under the umbrella of the CMIP6 and in particular VolMIP activity that explore the responses of the coupled ocean-atmosphere system to volcanic forcing, from the characterization of the mechanism of volcanically-forced climate variability and on the potential role of volcanic eruptions on future climate variability and predictability by means of observations, climate reconstruction studies and modeling approaches. We also welcome contributions conducted under PAGES-VICS activities from research aimed at better understanding volcanic impacts on historical and modern societies. We also invite contribution to the current international SPARC-SSiRC program, observational and modelling studies of the 2019 Raikoke aerosol cloud and from recent field campaigns. We further invite new results from H2020 transnational accesses to volcanic platforms and cross-studies coupling volcanology/atmospheric/health hazards, aspects of volcanic plumes science, their observation, modelling and impacts.

Co-organized by CL4/GMPV10
Convener: Myriam Khodri | Co-conveners: Pasquale Sellitto, Graham Mann, Emily Mason, Giuseppe G. Salerno, Claudia Timmreck, Matthew Toohey, Davide Zanchettin
| Attendance Wed, 06 May, 08:30–12:30 (CEST)

Orogenic plateaus and their margins are integral parts of modern mountain ranges and offer unique opportunities to study the feedback between tectonics and climate through the Earth’s surface. Complex interactions and feedbacks occur among a wide range of parameters, including crustal and deep-seated deformation, basin growth, uplift, precipitation and erosion, landscape and biological change; and lead to (i) the growth, recycling, and destruction of the lithosphere; (ii) shifts in surface elevation; and (iii) high topography that can affect atmospheric circulation. These controlling factors result in plateau lateral growth and its characteristic morpho-climatic domains: humid, high-relief margins that contrast with (semi-)arid, low-relief plateau interiors.

This session aims at creating a discussion forum on the complex interactions and feedbacks among climatic, surficial and geodynamic processes that challenge the notion of a comprehensive mechanism for surface uplift and topographic growth in orogenic plateaus and their margins. To fuel the exchange, we welcome studies of orogenic plateaus worldwide at various scales, from the Earth’s mantle and crust to its surface and atmosphere. We particularly encourage contributions that aim at bridging temporal and spatial gaps between datasets using an interdisciplinary approach or novel techniques.

Co-organized by CL4/GD5/GM9/SSP1
Convener: David Fernández-BlancoECSECS | Co-conveners: Maud J.M. Meijers, Alexander RohrmannECSECS, Flora BajoletECSECS
| Attendance Wed, 06 May, 14:00–15:45 (CEST)

This session investigates mid-latitude cyclones and storms on both hemispheres. We invite studies considering cyclones in different stages of their life cycles from the initial development, to large- and synoptic-scale conditions influencing their growth to a severe storm, up to their dissipation and related socioeconomic impacts.
Papers are welcome, which focus also on the diagnostic of observed past and recent trends, as well as on future storm development under changed climate conditions. This will include storm predictability studies on different scales. Finally, the session will also invite studies investigating impacts related to storms: Papers are welcome dealing with vulnerability, diagnostics of sensitive social and infrastructural categories and affected areas of risk for property damages. Which risk transfer mechanisms are currently used, depending on insured and economic losses? Which mechanisms (e.g. new reinsurance products) are already implemented or will be developed in order to adapt to future loss expectations?

Co-organized by CL4/NH1/OS1
Convener: Gregor C. Leckebusch | Co-conveners: Joaquim G. Pinto, Uwe Ulbrich
| Attendance Mon, 04 May, 16:15–18:00 (CEST)

Recent years have seen a substantial progress in the understanding of the nonlinear and stochastic processes responsible for important dynamical aspects of the complex Earth system. The Earth system is a complex system with a multitude of spatial and temporal scales which interact nonlinearly with each other. For understanding this complex system new methods from dynamical systems, complex systems theory, complex network theory, statistics and climate and Earth sciences are needed.

In this context the session is open to contributions on all aspects of the nonlinear and stochastic dynamics of the Earth system, including the atmosphere, the ocean and the climate system. Communications based on theoretical and modeling studies, as well as on experimental investigations are welcome. Studies that span the range of model hierarchy from idealized models to complex Earth System Models (ESM), data driven models, use observational data and also theoretical studies are particularly encouraged.

Invited Speaker: Anna von der Heydt (Utrecht University)

Co-organized by AS4/CL4/NH1/OS4
Convener: Christian Franzke | Co-conveners: Hannah Christensen, Balasubramanya Nadiga, Paul Williams, Naiming Yuan, François G. Schmitt, Guillaume Charria, Véronique Garçon
| Attendance Wed, 06 May, 14:00–15:45 (CEST)

Taking inspiration from the Mathematics of Planet Earth 2013 initiative, this session aims at bringing together contributions from the growing interface between the geophysical, the mathematical, and the theoretical physical communities. Specific topics include: PDEs, numerical methods, extreme events, statistical mechanics, pattern formation and emergence, (random and non-autonomous ) dynamical systems, large deviation theory, response theory, tipping points, model reduction techniques, coarse graining, stochastic processes, parametrizations, data assimilation, and thermodynamics. We invite talks and poster both related to specific applications as well as more speculative and theoretical investigations. We particularly encourage early career researchers to present their interdisciplinary work in this session.

Co-organized by AS4/CL4/NH1
Convener: Valerio Lucarini | Co-conveners: Peter Ashwin, Niklas BoersECSECS, Vera Melinda GalfiECSECS, Michel Crucifix, Hansjoerg Seybold, Piotr Szymczak
| Attendance Mon, 04 May, 14:00–18:00 (CEST)

The Arctic realm hosts vast extended continental shelves bordering old land masses, one of the largest submarine Large Igneous Provinces (LIPs) -the Alpha-Mendeleev Ridge - of Mesozoic age, and the slowest mid-ocean spreading ridge (the Gakkel Ridge) on the globe. Extreme variations in the evolution of landscapes and geology reflect the tug-of-war between the formation of new oceans, like the North Atlantic, and the destruction of older oceans: the South Anyui, Angayucham and North Pacific, which were accompanied by rifting, collision, uplift and subsidence. The causal relationships between the deep-mantle and surface processes in the Circum-Arcic region remain unclear. Geoscientific information on the relationship between the onshore geology and offshore ridges and basins in combination with variations in the mantle is the key for any deeper understanding of the entire Arctic Ocean.
This session provides a forum for discussions of a variety of problems linked to the Circum-Arctic geodynamics and aims to bring together a diversity of sub-disciplines including plate tectonics, mantle tomography, seismology, geodynamic modelling, igneous and structural geology, geophysical imaging, sedimentology, and geochemistry. Particularly encouraged are papers that address lithospheric-mantle interactions in the North Atlantic, the Arctic and North Pacific regions, mantle dynamics and vertical and horizontal motion of crustal blocks and consequences for paleogeography. As geologic and tectonic models are inherently tied with changes in the oceanographic and climatic development of the Arctic, we also invite studies that focus on the interplay between these processes and across timescales. Lastly, we would like to invite contributions from studies concerning the implications of how the Arctic’s geography and geology are portrayed by modern data and issues related to jurisdiction and sovereign rights with particular focus on the UN Convention on the Law of the Sea.

Co-organized by CL4/GMPV11/SM4/TS14
Convener: Grace E. ShephardECSECS | Co-conveners: Frances DeeganECSECS, Karolina Kośmińska, Rebekka Steffen
| Attendance Mon, 04 May, 14:00–15:45 (CEST)

Arid to sub-humid regions contribute ca. 40 % to the global land surface and are home of more than 40 % of the world’s population. During prehistoric times many important cultures had developed in these regions. Due to the high sensitivity of dryland areas even to small-scale environmental changes and anthropogenic activities, ongoing geomorphological processes but also the Late Quaternary palaeoenvironmental evolution as recorded in sediment archives are becoming increasingly relevant for geomorphological, palaeoenvironmental and geoarchaeological research. Dryland research is also boosted by methodological advances, and especially by emerging linkages with other climatic and geomorphic systems that allow using dryland areas as indicator-regions of global environmental change.
This session aims to pool contributions from the broad field of earth sciences that deal with geomorphological processes and different types of sediment archives in dryland areas (dunes, loess, slope deposits, fluvial sediments, alluvial fans, lake and playa sediments, desert pavements, soils, paleosols etc.) at different spatial and temporal scales. Besides case studies from individual regions and archives, methodical and conceptual contributions, e.g. dealing with the special role of eolian, fluvial, gravitational and biological processes in dryland environments, their preservation over time in the sedimentary records, and emerging opportunities and limitations to resolve past and current dynamics, are especially welcome in this session.

Co-organized by CL4/SSP2
Convener: Hans von Suchodoletz | Co-conveners: Markus Fuchs, Joel Roskin, Abi Stone, Lupeng Yu
| Attendance Fri, 08 May, 10:45–12:30 (CEST)