This open session invites contributions in the field of ocean and land climates, which do not fit into the specialized sessions. It will welcome presentations of modelling studies as well as (paleo)-observations. Here, papers will be collected from those sessions, which attracted a too small amount of contributions and did not fit into other specialized sessions both on climatology and paleoclimatology. However this is a session by itself and you must feel free to submit directly your paper to the Open session. This guarantees all authors an appropriate representation.
Opportunities of publishing your contribution is proposed in the on-line and open access EGU journal "Climate of the Past" www.climate-of-the-past.net

Processes responsible for formation and development of the early Earth (> 2500Ma) are not
well understood and strongly debated, reflecting in part the poorly preserved, altered, and
incomplete nature of the geological record from this time.
In this session we encourage the presentation of new approaches and models for the development of Earth's early crust and mantle and their methods of interaction. We encourage contributions from the study of the preserved rock archive as well as geodynamic models of crustal and mantle dynamics so as to better understand the genesis and evolution of continental crust and the stabilization of cratons.
We invite abstracts from a large range of disciplines including geodynamics, geology, geochemistry, and petrology but also studies of early atmosphere, biosphere and early life relevant to this period of Earth history.

The geological record provides insight into how climate processes may operate and evolve in a high CO2 environment and the nature of the climate system during a turnover from icehouse to greenhouse state — a transition that may potentially occur in the near future. Palaeoenvironmental records and climate models are two contrasting and yet complementary sources of information on past climates. Both approaches independently generate insights into the dynamics of the climate system. However, more information can be extracted about the drivers of climate variability and change when the two approaches are combined. The aim of this session is to share progress in our understanding of global changes based on the integration of geochemical/paleobotanical/sedimentological techniques and numerical models. We invite abstracts that reconstruct Earth’s climate, investigate how the interconnections of the key surface reservoirs (vegetation-ocean-atmosphere-cryosphere-biogeochemistry) impact climate, identify tipping points and thresholds and studies that use climate model outputs to understand the physical controls of climate variability. Pertinent themes may include greenhouse-icehouse transitions and intervals testifying for extreme changes.
We are pleased to have Martin Ziegler as our invited speaker talking about "Cenozoic climate evolution revealed by clumped isotope thermometry".

This session aims to showcase an interesting diversity of state-of-art advances in all aspects of Phanerozoic stratigraphy, paleoceanography, paleoclimatology, eustasy, and orogeny on long- and short timescales in marine and terrestrial environments. Within this broad topic, contributions include but are not limited to, case studies of organic and inorganic geochemistry, sedimentology, paleontology, and modeling, alongside integrated approaches to understanding evolving earth processes, particularly climate transitions and their consequences. The session will potentially be organized into thematic blocks to allow more in-depth exploration and discussion of topics.

Orbital forcing is the most important known external driver of the climate system. Nevertheless, resultant internal climate feedbacks that invoke different climate components across different time scales play a critical role in defining the climate response to orbital forcing. These internal climate feedbacks are particularly apparent at past climate transitions, which cannot be simply explained by orbital changes alone (e.g. glacial inception and termination, the mid-Brunhes transition, the mid-Pleistocene transition, Pliocene-Pleistocene transition).

In this interdisciplinary session, we aim to bring together studies of centennial-to-orbital scale interactions among the atmosphere-ocean system, cryosphere, and carbon cycle that advance our understanding of the climate system during climate transitions. Modeling, theoretical and proxy-based studies as well as novel methodologies that combine the above approaches are especially encouraged.

Keynote talk "Ocean carbon storage and release over a glacial cycle" by Dr. James Rae, School of Earth & Environmental Sciences, University of St Andrews

Public information:
In this session, online displays will be present mainly by live talks in “GoToMeeting” room (similar as Zoom). Since some of authors cannot join in online video chat room, the conveners will try to make essential information accessible in the text-based chat room. In addition, we will eventually move to the chat room after the talks in “GoToMeeting” room. Here is the room information:
----------------------------------------------------
EGU2020 online session CL1.8
Fri, May 8, 2020 1:55 PM - 3:45 PM (CEST)

Please join my meeting from your computer, tablet or smartphone.
https://global.gotomeeting.com/join/880800221

You can also dial in using your phone.
Germany: +49 892 0194 301

Access Code: 880-800-221

Reconstructions of past climate conditions have clearly demonstrated that the spatio-temporal variability of Earth´s climate is paced by orbital forcing and tectonic processes. However, the mechanisms that translate these forcing signals into climate changes and subsequently geoarchives continue to be debated. We invite submissions that explore the climate system response to various forcing mechanisms, and that test the stability of these relationships under different climate regimes or across evolving climate states during the Phanerozoic. A special focus is given to the Pliocene epoch between ~5.3 to 2.7 Ma, which has been proposed as an analogue for future climates, since it is characterised by CO2 concentrations which align with those recorded today and projected for the end of this century under moderate emissions scenarios.
Submissions exploring proxy data and/or modelling work are welcomed, as this session aims to bring together proxy-based, theoretical and/or modelling studies focused on global and regional climate and ecosystem responses to orbital, tectonic and ocean gateway forcing at different time scales. We also encourage contributions linked to the PAGES-PlioVAR and PlioMIP2 programmes.

Abrupt climate change is a recurring feature of the Earth’s history and the current anthropogenic interference has set the climate system on a potential abrupt change trajectory. As with past climate change, future climate changes are not predicted to affect all areas of the planet in the same way, or at the same rate, yet mechanisms for spatiotemporal differences are complex and difficult to predict from low-resolution global models.
Increasingly detailed high temporal resolution proxy reconstructions of past abrupt climate transitions and oscillations (such as the Late Glacial-Holocene transition, Heinrich Stadials or the Dansgaard-Oeschger cycles) have been produced for widely distributed ice core, marine and terrestrial records. When precisely integrated (i.e. via cosmogenic isotopes, palaeomagnetic excursions, tephra) these now allow for an integrated assessment of the anatomy, the spatially variable consequences and the mechanisms of abrupt climate transitions.
With a focus on the period from the last interglacial to the pre-Industrial, this session will assess methodologies (numerical and/or proxy based) and findings from studies of the spatiotemporal anatomy of the climate system on decadal to millennial timescales. We invite contributions that evidence regional climate thresholds and gradients, explore their consequences for human societies and identify mechanisms from the integration of local to global proxy records as well as modelling approaches. Finally, we explore how findings from such precisely integrated records in space and time can serve to quantify vulnerabilities and regional thresholds relevant for the anthropogenic climate change trajectory.

Public information:
The session will run May 6 from 10:45 to 12:30 in the text-based chat of the EGU website:
https://meetingorganizer.copernicus.org/EGU2020/displays/36721

with an additional moderation and presentation in a Zoom meeting room, see details in the Session materials. Please join the text based chat and if you can also the Zoom room. We have decided to add Zoom to make the session more personal and to give authors the chance to introduce their work in person. If you can’t/don’t want to/are not allowed to use Zoom, don’t worry, we as the conveners will try to make all information accessible in the text based chat. Please see the session materials for schedule and detailed instructions.

The carbon cycle and climate are tightly linked over millennia and centennial time scale, as is exemplified by the synchronous changes between CO2 and Antarctic temperature recorded in ice cores. Aside from CO2, other data such as carbon isotopes also show strong changes in the carbon cycle between the colder Last Glacial Maximum and warmer pre-industrial. However, despite decades of research with data and climate models, no complete explanation has emerged to account for all data records. We invite contributions from both proxy data and models tackling these issues and bringing new insights on the carbon cycle changes during the Last Glacial Maximum and last deglaciation. In particular, we welcome contributions from models of all complexities from simple theoretical models to complex GCMs, as well as new records or interpretation of proxy data from ice and sediment cores, spanning centennial to millennial time scales and involving ocean or land processes.
Our invited speaker will be Alice Marzocchi talking about "Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice".

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.

Public information:
Brief live chat info (10:45 am - 12:30 pm CET Tuesday 5th May)
- 10:45 am - 11:45 am: discussion of the uploaded presentations (similar to PICO sessions)
where presenters can explain their slides/answer questions
- 11:45 am - 12:30 pm: group discussion on 2 to 3 broader topics based on the themes of
the presentations
- We encourage short powerpoint presentations (1-3 slides)
- Choose a single focus and main conclusion from your presented research

Earth history is punctuated by major extinction events, by perturbations of global biogeochemical cycles and by rapid climate shifts. Investigation of these events in Earth history is based on accurate and integrated stratigraphy. This session will bring together specialists in litho-, bio-, chemo-, magneto-, cyclo-, sequence-, and chronostratigraphy with paleontologists, paleoclimatologists and paleoceanographers. An emphasis is placed upon the use of a variety of tools for deciphering sedimentary records and their stratigraphy across intervals of major environmental change. This session is organized by the International Subcommission on Stratigraphic Classification (ISSC) of the International Commission on Stratigraphy (ICS) and it is open to the Earth science community at large.

Public information:
During the chat, on Tue 05 May, 16:15–18:00, all 10 abstracts with uploaded display material will be open for discussion. The conveners will moderate the chat discussion. We will discuss the abstracts in the order in which they appear in the program. After we call an abstract, we ask the author to provide the chat room with a 1-2 line summary of their work (best to copy-paste a pre-written sentence). Then we can proceed to Q&A. We kindly ask all chat room participants to keep the chat on subject, and not to disrupt the Q&A.

Of course, if you upload your display last-minute, we will also make time to discuss yours. Don't hesitate to share your science!

Significant advances in our understanding of the Meso- and Cenozoic development of polar regions have been made over the last two decades by studying continental shelf, slope, or deep sea sediment sequences. These include more detailed reconstructions of the climatic, oceanographic, and tectonic evolution of high northern and southern latitudes over various time scales, as well as reconstructions of past ice-sheet dynamics and studies of marine geohazards. Data have been obtained from conventional and high-resolution 2D and 3D seismic surveying, as well as from a growing number of short sediment cores and targeted high-latitude deep drilling expeditions (e.g. IODP, MeBO). The same techniques have also been applied in fjords, which link the continental margins with the interiors of landmasses and act as “miniature ocean basins”. Fjord settings allow us to study similar geological processes to those that acted on glaciated continental margins but at smaller scales. The variety of sediment inputs (e.g. glacial, fluvioglacial, fluvial, biological) to fjord basins along with relatively high sedimentation rates provides the potential for high-resolution palaeoclimatic and palaeooceanographic records on decadal to centennial timescales.

The aim of this session is to bring together researchers working on both northern and southern high latitudes processes spanning various spatio-temporal scales, to provide a multi-disciplinary picture of polar regions. We welcome submissions focussing on (but not limited to) records of past climatic change, tectonics, oceanography and ecosystems, and the associated links with ice sheets and glacier behaviour, ice-ocean interactions and glacial-marine sedimentary processes. Studies that integrate different datasets, data types, or that marry observations with numerical modelling are also encouraged.

Public information:
Session schedule:

14.00-14.02 Welcome and introduction

14.02-14.10 D3130 | EGU2020-7493 David Hutchinson et al., Arctic closure as a trigger for Atlantic overturning at the Eocene-Oligocene Transition

14.10-14.18 D3131 | EGU2020-7943 Katrien Van Landeghem et al., Relating changes in seabed properties and retreating glacier fronts in West-Antarctic fjords

14.18-14.26 D3135 | EGU2020-12484 Joe Stoner et al., Deriving paleo-perspectives on polar systems: Continued results from the 2012 Sawtooth Lake (Ellesmere Island) and 2015 Petermann (North Greenland) Expeditions

14.26-14.34 D3136 | EGU2020-768 Julia Rieke Hagemann et al., Southern Chilean continent-ocean interaction over the last glacial cycle

14.34-14.42 D3140 | EGU2020-10921 Tom Arne Rydningen et al., New results on the dynamics of the NW part of the Svalbard Ice Sheet during the deglaciation of the Woodfjorden Trough

14.42-14.50 D3142 | EGU2020-12940 Michele Rebesco et al., Multi-proxy analysis of Late Quaternary ODYSSEA Contourite Depositional System (Ross Sea, Antarctica) and the depositional record of contour current and cold, dense waters

14.50-14.58 D3143 | EGU2020-13950 Juliane Müller et al., Deglacial sea ice variability at the continental margin off western Dronning Maud Land

14.58-15.06 D3144 | EGU2020-17953 Jostein Bakke et al., Late glacial and Holocene glacier fluctuations at the Sub-Antarctic Island Kerguelen in the Southern Indian Ocean

15.06-15.14 D3145 | EGU2020-18143 Marie Protin et al., Geological, geochemical and cosmogenic nuclides constraints from the NEEM core basal sediments, Greenland

15.14-15.22 D3147 | EGU2020-19076 Kseniya Mikhailova et al., Glendonites from Mesozoic succession of eastern Barents sea: distribution, genesis and paleoclimatic implications

15.22-15.30 D3148 | EGU2020-19216 Eivind W. N. Støren et al., Reconstruction of Holocene glacier fluctuations at Kongsbreen based on sediments deposited in lake Sarsvatnet, Ossian Sarsfjellet, Svalbard

15.30-15.45 General discussion and outstanding questions

This session aims to place recently observed climate change in a long-term perspective by highlighting the importance of paleoclimate research spanning the past 2000 years.
We invite presentations that provide insights into past climate variability, over decadal to millennial timescales, from different paleoclimate archives (ice cores, marine sediments, terrestrial records, historical archives and more). In particular, we are focussing on quantitative temperature and hydroclimate reconstructions, and reconstructions of large-scale modes of climate variability from local to global scales.This session also encourages presentations on the attribution of past climate variability to external drivers or internal climate processes, data syntheses, model-data comparison exercises, proxy system modelling, and novel approaches to producing multi-proxy climate field reconstructions.

The Ancient Silk Road was one of the most important passages for trans-Eurasia exchange and human migration, which witnessed the rise and fall of ancient civilizations in Central Eurasia. In the central part of the Ancient Silk Road, where the climate condition is extremely dry and the ecosystem is very fragile. The climate and environment changes, especially the water resources change in this area, can significantly influence the spatio-temporal distribution of Ancient Silk Road network, the trans-Eurasia exchange and human migration along the Ancient Silk Road, and the civilization evolution of these ancient cities and towns among the Ancient Silk Road network. This session aims to explore the history of trans-Eurasia exchange, human migration, Ancient Silk Road network spatial change, civilization evolution and climate and environment change, as well as relationship among them in the areas along the Ancient Silk Road. We welcome presentations concerning these issues from multi-disciplinary perspectives, to promote the advancements of research in the field.

Public information:
Authors are kindly asked to upload display material by Sunday, 26th April, 2020, so that there is one week prior to the online chat for viewing the displays.

Program for the Live Chat on 4th May, 2020, 8.30 - 10.15 CEST (14:30–16:15 PM, Beijing)

14:20–14:30 PM, Beijing Sign in and introduction to session

1. D2537, EGU2020-21976（14:30-14:40 PM, Beijing）
Pollen-based quantitative land-cover reconstruction for northern Asia covering the last 40 ka
Xianyong Cao, Fang Tian, Furong Li, Marie-José Gaillard, Natalia Rudaya, Qinghai Xu, and Ulrike Herzschuh
2. D2539, EGU2020-3185（14:40-14:50 PM, Beijing）
An n-alkane-based Holocene climate reconstruction in the Altai Mountains, northern Xinjiang, China
Min Ran
3. D2542, EGU2020-6328（14:50-15:00 PM, Beijing）
Variation of bacterial communities in Muztagh ice core from 1869 to 2000
Yongqin Liu, Tandong Yao, and Baiqing Xu
4. D2549, EGU2020-13015（15:00-15:10 PM, Beijing）
Changes in the hydrodynamic intensity of Bosten Lake and its impact on early human settlement in the northeastern Tarim Basin, eastern Arid Central Asia
Haichao Xie
5. D2550, EGU2020-4601（15:10-15:20 PM, Beijing）
Holocene moisture variations in western arid central Asia inferred from loess records from NE Iran
Qiang Wang, Haitao Wei, Farhad Khormali, Leibin Wang, Haichao Xie, Xin Wang, Wei Huang, Jianhui Chen, and Fahu Chen
6. D2551, EGU2020-3196（15:20-15:30 PM, Beijing）
Holocene moisture variations in the Tianshan Mountains and their geographic coherency in the mid-latitude Eurasia: A synthesis of proxy records
Yunpeng Yang
7. D2553, EGU2020-5067（15:30-15:40 PM, Beijing）
Mid-late Holocene hydroclimate variation in the source region of the Yangtze River revealed by lake sediment records
Xiaohuan Hou, Lina Liu, Zhe Sun, Xianyong Cao, and Juzhi Hou
8. D2554, EGU2020-4965（15:40-15:50 PM, Beijing）
Late Holocene Varve Chronology and High-Resolution Records of Precipitation in the Central Tibetan Plateau
Kejia Ji, Erlei Zhu, Guoqiang Chu, and Juzhi Hou
9. D2555, EGU2020-3874（15:50-16:00 PM, Beijing）
The forced response of Asian Summer Monsoon precipitation during the past 1500 years
Zhiyuan Wang, Jianglin Wang, Jia Jia, and Jian Liu

Discussion and summery（16:00-16:15 PM, Beijing）

While the information, preserved in the records of instrumental measurements, provide an inside view into the history of weather-related extremes of the last 100-150 years or shorter, documentary evidence and the results of natural scientific investigations allow to extend this knowledge several centuries (or millennia) into the past. This concerns, for example those disastrous extremes which were not recorded in the instrumental period, but are known from documentary sources. Compared to palaeo-hydrological investigations of extremes, the papers presented in this session are aimed to provide high-resolution information (with exact dating) based on data derived from documentary evidence, covering a period that does not exceed one-two millennia.
On the one hand, investigations focused on the long-term understanding of variability, changes and shifts in the climatic and/or hydrological regime as well as in the frequency/magnitude of meteorological and hydrological extremes and hazards are welcome. On the other hand, investigations concentrating on one or more great extreme events (extreme cold, heat, floods, droughts etc.) are also invited in the session. Papers discussing the detection of causes of hydrological, meteorological extremes and hazards (environmental, atmospheric/climatic and society-related) in historical times are also addressed and supported to participate in the session. Thus, another important topic of the session is socio-economic responses on extremes or catastrophic events as well as long-term changes, development in cooping weather-related natural hazards. As an integrate part of socio-economic response, the perception and social representation of weather and hydrological hazards and extremes (e.g. floods, droughts) in historical periods are also valuable topics of discussion in the session.
Since this research requires the development of regional chronologies based on good-quality historical sources, besides natural and applied scientists, the active presence and work of historians is of vital importance. The results of historical hydrology investigations and the study of hydro-meteorological extremes in historical times may be utilised in a number of areas such as risk assessment, flood control, hydrological forecasting/predictions, socio-hydrology or in the understanding of the main drivers of hydro-morphological processes.

Interdisciplinary study of the Northeast Atlantic region offers an extraordinary opportunity to advance understanding of interactions and co-dependencies between the solid Earth, ocean, atmosphere, cryosphere and climate. Understanding these issues are of critical importance to Europe and Scandinavia, and they are of global relevance. The unprecedented surge in exploration of the Northeast Atlantic Realm that has unfolded in recent years has delivered major leaps forward in understanding its geological structure, dynamics and development, economic resources and volcanism. Examples include the complexity of the conjugate volcanic rifted margins, contact metamorphism of carbon-rich shales by sill intrusions, producing thermogenic methane, the discovery of widespread continental crust in the ocean, the critical role of the Greenland-Iceland-Faroe bathymetric ridge in influencing ocean circulation between the Arctic and the Atlantic south of Iceland, mapping of gas hydrates and the study of crustal structure beneath the Greenland icecap. Throughout the Cenozoic these factors have influenced ocean and atmosphere composition and circulation, climate change, and the growth, wastage and transport of ice. Detailed understanding of the interdependencies of these phenomena in the past and through time is arguably of critical importance to understanding the current, rapid changes in the natural environment. The goal of this special session is to bring together diverse contributions drawing on all the above disciplines in order to identify potentially fertile areas for broad, cross-disciplinary study of the Northeast Atlantic Realm moving forward.

In recent decades, quantitative methods have become increasingly important in the field of palaeoenvironmental, palaeoclimatic and palaeohydrological reconstruction, due to the need for comparison between different records and to provide boundary conditions for computational modelling. Continental environmental archives (e.g. speleothems, lake sediments, land snails, rivers, or peatlands) are often highly temporally resolved (subdecadal to seasonal) and may provide more direct information about atmospheric and hydrological processes than marine archives. The wide variety of archive types available on land also allows for intercomparison and ground-truthing of results from different techniques and proxies, and multi-proxy reconstructions from the same archive can disentangle local and supra-regional environmental conditions. This approach is particularly useful for the reconstruction of hydrological dynamics, which are challenging to reconstruct due to their high spatial variability, signal buffering, nonlinearities and uncertainties in the response of palaeoclimate archives and proxies. For example, climate-independent factors such as land cover change can affect the local to regional water availability recorded in proxies.

This session aims to highlight recent advances in the use of innovative and quantitative proxies to reconstruct past environmental change on land. We present studies of various continental archives, including but not limited to carbonates (caves, palaeosols, snails), sediments (lakes, peatlands, rivers, alluvial fans), and biological proxies (tree rings, fossil assemblages, biomarkers). We particularly include studies involving the calibration of physical and chemical proxies that incorporate modern transfer functions, forward modeling and/or geochemical modeling to predict proxy signals, and quantitative estimates of past temperature and palaeohydrological dynamics. We also include reconstructions of temperature and hydrologic variability over large spatial scales and palaeoclimate data assimilation. This session will provide a forum for discussing recent innovations and future directions in the development of terrestrial palaeoenvironmental proxies on seasonal to multi-millennial timescales.

Public information:
Please note that the order and number of presentations has been changed as some authors could not attend under the circumstances, or have parallel duties.

Authors are kindly asked to upload display material by Friday, 1st May, 2020 so that there is the weekend prior to the online chat for viewing the displays.

Our Programme for the Live Chat on 4th May, 2020, 10.45 - 12.30 CET

10.45 - 10.50 Sign in and introduction to session

10.50 - 10.56
D3703 | EGU2020-12712
Changes in biogeochemistry recorded in the Lisan formation and the Dead Sea Basin
Alexandra Turchyn, Harold Bradbury, and Adi Torfstein

10.56 - 11.02
D3707 | EGU2020-21994
Holocene climate in Northern Urals (Komi Republic, Russia): a multiproxy approach based on pollen and brGDGTs
Chéïma Barhoumi, Sébastien Joannin, Adam A. Ali, Guillemette Ménot, Yulia Golubeva, Dmitri Subetto, Alexander Kryshen, Igor Drobyshev, and Odile Peyron

11.02 - 11.08
D3708 | EGU2020-1150
Primary production in a kettle lake (Canada) was not driven by effective moisture over the last ~900 years
Rebecca Doyle, Zijun Liu, Jacob Walker, Ryan Hladyniuk, Katrina Moser, and Fred Longstaffe

11.08 - 11.14
D3731 | EGU2020-18227
Reconstructing past hydrology from drift sand archives: possibilities and limitations
Koen Beerten, Wouter van der Meer, Koen Hebinck, Miel Schurmans, and Jan Bastiaens

11.14 - 11.20
D3709 | EGU2020-19247
Global hydroclimate of the Last Interglacial: precipitation, river discharge, floods
Paolo Scussolini and the Last Interglacial Floods

11.20 - 11.26
D3705 | EGU2020-18100
A 1,600 year record of paleoseasonality from the neotropics of Central America and its implications for rainfall predictability in agricultural societies
Keith Prufer, Sebastian Breitenbach, James Baldini, Tobias Braun, Erin Ray, Lisa Baldini, Victor Polyak, Franziska Lechleitner, Norbert Marwan, Douglas Kennett, and Yemane Asmerom


D3725 | EGU2020-11105
CANCELLED :-(
Nehme et al.: Speleothem record from Pentadactylos cave (Cyprus): high resolution insight into climatic variations during MIS 6 and MIS 5

11.26 - 11.32
D3723 | EGU2020-2397
Application of novel trace analysis methods for lignin and levoglucosan in flowstone samples from New Zealand during the Holocene
Anja Beschnitt and Thorsten Hoffmann

11.32 - 11.38
D3724 | EGU2020-2413
Trace analysis of levoglucosan and lignin-phenols in speleothems by HILIC-UHPLC-ESI-HRMS: A new method
Julia Homann, Anja Beschnitt, and Thorsten Hoffmann

11.38 - 11.44
D3726 | EGU2020-16898
Rainfall seasonality changes in northern India across the 4.2 ka event
Alena Giesche, Sebastian F.M. Breitenbach, Norbert Marwan, Adam Hartland, Birgit Plessen, Jess F. Adkins, Gerald H. Haug, Amanda French, Cameron A. Petrie, and David A. Hodell

11.44 - 11.50
D3720 | EGU2020-992
Structural ecosystem change in Holocene chironomid assemblages
Roseanna Mayfield, Peter Langdon, John Dearing, Patrick Doncaster, and Rong Wang

11.50 - 11.56
D3711 | EGU2020-5311
Paleoclimatic reconstruction studies in lake sediments: major proxies, technical evolution and database
Paula Bianchini, Elder Yokoyama, and Luciana Prado

11.56 - 12.02
D3715 | EGU2020-12592
Biomarker (brGDGT) degradation and production in lacustrine surface sediments: Implications for paleoclimate reconstructions
Cindy De Jonge, Annika Fiskal, Xingguo Han, and Mark Lever

12.02 - 12.08
D3721 | EGU2020-8457
A theory of palaeoclimate reconstruction
Mengmeng Liu, Iain Colin Prentice, Cajo ter Braak, and Sandy Harrison

12.08 - 12.14
D3729 | EGU2020-4240
What we talk about when we talk about seasonality?
Ola Kwiecien

12.14 - 12.20
D3732 | EGU2020-4887
Reconstructions of past sediment and water discharges from fluvial-fill terraces in the southern Central Andes of NW Argentina
Stefanie Tofelde, Taylor Schildgen, Andrew Wickert, Manfred Strecker, and Ricardo Alonso

12.20 - 12.30 Summary of session

Tree rings are one of nature’s most versatile archives, providing insight into past environmental conditions at annual and intra-annual resolution and from local to global scales. Besides being valued proxies for historical climate, tree rings are also important indicators of plant physiological responses to changing environments and of long-term ecological processes. In this broad context we welcome contributions using one or more of the following approaches to either study the impact of environmental change on the growth and physiology of trees and forest ecosystems, or to assess and reconstruct past environmental change: (i) traditional dendrochronological methods including studies based on tree-ring width and density, (ii) stable isotopes in tree rings and related plant compounds, (iii) dendrochemistry, (iv) quantitative wood anatomy, (v) ecophysiological data analyses, and (vi) mechanistic modelling, all across temporal and spatial scales.

In an era of science that uses numerical models to better understand physical processes occurring on Earth, there is an increasing demand for robust empirical datasets to constrain these simulations. Generating robust datasets, especially data sets that express stratigraphic positions of sedimentary deposits as ages, often involves the use of multiple, independent geochronological techniques (e.g. different kinds of radioisotopic dating, magneto-, bio-, cyclostratigraphy and sedimentologic relationships along the succesion). The integration of these different kinds of geochronological information often poses challenges.

Age-depth models are the ultimate result of the integration of different geochronological techniques, and range from linear interpolation to more complex Bayesian techniques. We will introduce several modelling concepts and their application in a range of paleoenvironmental and paleoclimatic records. The Short Course will provide an introduction to the field of (Bayesian) age-depth models and will highlight the assumptions, benefits and limitations of different model approaches. It will prepare participants for independent application of suitable age-depth models to their data.

Public information:
We are planning on holding a 2-day course in Bremen this autumn, please keep an eye on the following website
https://www.marum.de/Ausbildung-Karriere/Courses-2020.html
and/or ask Christian.Zeeden@leibniz-liag.de to be informed on news regarding this.

Speleothems and continental carbonates (e.g. travertines, anthropogenic travertines, subglacial and cryogenic carbonates) are important continental archives, which can provide precisely dated, high-resolution records of past environmental and climate changes across all climate zones. This session aims to showcase the most recent developments and findings related to analytical developments, process understanding, and new records on annual, seasonal, sub- and orbital timescales. In this session, contributions are particularly welcome on: (1) monitoring of soil and cave systems in order to improve understanding of the speleothem and continental carbonate archive; (2) high-resolution orbital and sub-orbital palaeoclimate reconstructions on Quaternary timescales and longer; (3) new and novel techniques as well as methodological developments as applied to speleothems and continental carbonates; (4) interdisciplinary approaches that combine speleothem and/or continental carbonate records with other proxy archives and/or modelling.

Public information:
Authors are kindly asked to upload display material by Sunday, 26th April, 2020 so that there is one week prior to the online chat for viewing the displays.

Programme for the Live Chat on 4th May, 2020, 8.30 - 10.15 CET

8.30 - 8.35: Sign in and introduction to session

8.35 - 8.45
D3733 | EGU2020-1686
Insights into recharge processes and speleothem proxy archives from long-term monitoring networks of cave drip water hydrology
Andy Baker, Pauline Treble, Andreas Hartmann, Mark Cuthbert, Monika Markowska, Romane Berthelin, Carol Tadros, Matthias Leopold, and Stuart Hankin

8.45 - 8.55
D3735 | EGU2020-140
A long continuous palaeoclimate-palaeoenvironmental record of the last glacial period from southern Italy and implications for the coexistence of Anatomically Modern Humans and Neanderthals
Andrea Columbu, Veronica Chiarini, Christoph Spötl, Jo De Waele, Stefano Benazzi, John Hellstrom, and Hai Cheng

8.55 - 9.05
D3736 | EGU2020-4800
History of Late Pleistocene Permafrost in Southern Ural revealed by studies of speleothems and cave sediments
Yuri Dublyansky, Gabriella Koltai, Denis Scholz, Michael Meyer, Luke Gliganic, Olga Kadebskaya, Hai Cheng, and Christoph Spötl

9.05 - 9.15
D3739 | EGU2020-1054
Using hierarchical dynamic time warping to synchronize age-uncertain (proxy) time series
Yuval Burstyn and Asaf Gazit

9.15 - 9.25
D3741 | EGU2020-11089
Monitoring activities in several caves along a transect stretching from the Adriatic Sea to the Aggtelek Karst (NE-Hungary): trace element and stable isotopic compositions of drip waters and cave carbonates
György Czuppon, Attila Demény, Neven Bocic, Nenad Buzjak, Krisztina Kármán, Zsófia Kovács, Szabolcs Leél-Össy, Szilárd John, Mihály Óvári, and Emese Bottyán

9.25 - 9.35
D3744 | EGU2020-7466
Understanding the deglacial relationship between carbon isotopes and temperature in stalagmites from Western Europe
Franziska A. Lechleitner, Christopher C. Day, Micah Wilhelm, Negar Haghipour, Oliver Kost, Gideon M. Henderson, and Heather M. Stoll

9.35 - 9.45
D3751 | EGU2020-19608
Climate driven mobility of the early humans in SW Asia: Preliminary evidence from Iranian Stalagmites
Arash Sharifi, Ali Pourmand, Mehterian Sevag, Peter Swart, Larry Peterson, and Hamid A. K. Lahijani

9.45 - 9.55
D3752 | EGU2020-18326
The Maya Terminal Classic Drought replicated in two stalagmites from Columnas Cave, NW Yucatán
Daniel James, Sebastian Breitenbach, Hai Cheng, Adam Hartland, Ian Orland, Mark Brenner, Jason Curtis, Christina Gallup, Soenke Szidat, John Nicolson, James Rolfe, Andrew Mason, Gideon Henderson, and David Hodell

9.55 - 10.05
D3753 | EGU2020-10343
Holocene hydroclimate of the Volga Basin recorded in speleothems from the Central and Southern Ural Mountains, Russia
Jonathan Baker, Yuri Dublyansky, Olga Kadebskaya, Denis Scholz, Gabriella Koltai, Hanying Li, Jingyao Zhao, Christoph Spötl, and Hai Cheng

10.05 - 10.15 - Open Discussion

Inspired by the classic textbook “Tracers in the Sea” (Broecker and Peng, 1982) for the session’s name, we invite contributions bearing on chemical and isotopic tracers used in paleoceanography. Proxies are the backbone of paleoceanography and undergo frequent new developments. New analytical techniques and applications allow for the investigation of new proxy systems as well as the exploration of existing proxies with new substrates or more challenging sample sizes. Growing datasets have led, and are leading, to comprehensive compilations, proxy inter-comparisons, and quantitative tests of paleoceanographic model simulations. For this session, we invite presentations on both (i) modern calibrations and downcore applications, (ii) single and multiple proxies, and (iii) proxy measurements and modeling. Despite their wide applications, paleoceanographic proxies suffer generally from significant limitations. As illustrated in a famous figure by the late H. Elderfield, our confidence in a proxy goes from an optimism phase, to a pessimism phase, and eventually to a realism phase. In this spirit, both “good” and “bad” news during the development and application of proxies are welcome.

Soil-forming processes can be observed at various spatial and temporal scales, including molecular - microscopic - pedon - landscape scales, and a similarly wide range of temporal scales. They are influenced not only by the “classical five” soil-forming factors, but also by the factor “humans”. This holds true not only for the industrial period and urbanized areas, but also for palaeopedological and archaeological contexts.
In this session, we seek abstracts on all of these aspects of “soils as records in time and space”:
- soil processes proceeding at different scales, incl. interactions across scales (both spatial and temporal)
- human-induced soil changes (incl. mechanical and chemical changes, as well as the introduction of artificial parent materials)
- advances in understanding weathering mechanisms and mineralogical changes in time and space
- linkages of spatial patterns and processes in soil landscapes over time
- processes taking place on short time scales, thereby contributing to long-term soil changes
- aeolian inputs to soils, implications for soil genesis and ecologically relevant soil properties
- palaeosols and geomorphic features as records of former environments and human activity
- use of soil classification and soil maps, and possibly links to digital soil mapping and novel soil survey techniques such as proximal sensing technologies and detailed digital elevation models.

(Bio)minerals, in particular carbonates (but also others e.g. phosphates), play an essential role in shaping our understanding of the evolution of life and the Earth System, and constitute one of the most important archives of past climatic and environmental conditions. Geochemical, petrographic or crystallographic approaches have yielded new insights into the physico-chemical conditions governing their formation, including through biomineralisation pathways. These capture vital information about the environment and fluid chemistry during precipitation in the form of their specific elemental or isotopic signatures, mineralogies or micromorphologies. Over the past decades, a refined understanding of both biogenic as well as abiotic carbonates and other mineral archives, together with the development of new analytical methods and palaeo-proxies, has led to numerous breakthroughs in palaeoclimate research. However, the quality and reliability of the climatic and environmental information we extract from these records depends, critically, on careful proxy calibrations and the evaluation of secondary controls such as kinetic or vital effects and diagenetic influences. This session seeks contributions from sedimentology, geochemistry, (palaeo)biology, and mineralogy that utilise carbonate or other relevant (bio)minerals to improve our understanding of past environmental conditions over a broad range of timescales, including (but not limited to) microbialites, mollusc shells, coral skeletons or foraminifera. We welcome experimental or theoretical studies dealing with culturing of calcifying organisms, synthetic mineral precipitation, transformation or alteration processes, elemental partitioning or isotopic fractionation (to give but a few examples). The aim of this session is to synthesize recent progress on the investigation as well as application of these important archives, and to showcase methodological advances that will help us to build a more comprehensive understanding of past global changes.

Interactions between tectonics, climate and biotic evolution are ideally expressed in Asian orogenies. The ongoing surge of international research on Asian regions enables to better constrain paleoenvironmental changes and biotic evolutions as well as their potential driving mechanisms such as global climate, the India-Asia collision and the tectonic growth of the Himalayan-Tibetan and other Asian orogens. Together these efforts allow for a comprehensive paleogeographic and paleoenvironmental reconstructions that enable to constrain climate modelling experiments which permit validation of hypotheses on potential interactions.
The goal of this session is to assemble research efforts that constrain Asian tectonic, climate (monsoons, westerlies, aridification), land-sea distribution, surface processes or paleobiogeographic evolution at various timescales. We invite contributions from any discipline aiming for this goal including broadly integrated stratigraphy, tectonic, biogeology, climate modelling, geodynamic, oceanography, geochemistry or petrology.

Today the Indo-Pacific Warm Pool (IPWP) represents a crucial part of the global thermohaline circulation by acting as a low latitude heat source for the polar regions. The IPWP’s importance in deciphering past and future coupled ocean-atmosphere dynamics is highlighted by the complex interactions between this region and globally significant climatic systems like the Australasian Monsoon, Intertropical Convergence Zone (ITCZ), El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD).

This session will explore the IPWP’s role in global climate change and its emergence as a biogeographic diversity hot spot from the geological past to the present. We invite submissions on a broad range of topics in sedimentology, palaeontology, paleoclimatology/-oceanography, and data-model comparisons to assemble a comprehensive view of the Cenozoic evolution of the entire Indo-Pacific Region. We encourage submissions stratigraphically synthesising marine-terrestrial multi-proxy archives, and those investigating teleconnections between the IPWP, zonal (ENSO/IOD), and high latitude processes. Finally, this session will examine how the long-term evolution of the global monsoons and the ITCZ affected feedbacks between IPWP, Australasian hydroclimate and tectonic/weathering processes.

The radiation budget of the Earth is a key determinant for the genesis and evolution of climate on our planet and provides the primary energy source for life. Anthropogenic interference with climate occurs first of all through a perturbation of the Earth radiation balance. We invite observational and modelling papers on all aspects of radiation in the climate system. A specific aim of this session is to bring together newly available information on the spatial and temporal variation of radiative and energy fluxes at the surface, within the atmosphere and at the top of atmosphere. This information may be obtained from direct measurements, satellite-derived products, climate modelling as well as process studies. Scales considered may range from local radiation and energy balance studies to continental and global scales. In addition, related studies on the spatial and temporal variation of cloud properties, albedo, water vapour and aerosols, which are essential for our understanding of radiative forcings and their relation to climate change, are encouraged. Studies focusing on the impact of radiative forcings on the various components of the climate system, such as on the hydrological cycle, on the cryosphere or on the biosphere and related carbon cycle, are also much appreciated. This session will include a dedicated section with the aim to move towards an harmonization of ground measurements of the surface radiation budget over land and ocean, with particular attention to the definition of best practices, uncertainties and traceability to standards.

Invited Speaker: Robert Weller (Woods Hole Oceanographic Institution, Massachusetts, USA)

Changes in seasonal timing affect species and ecosystem response to environmental change. Observations of plant and animal phenology as well as remote sensing and modeling studies document complex interactions and raise many open questions.

We invite contributions with cross-disciplinary perspectives that address seasonality changes based on recent plant and animal phenological observations, pollen monitoring, historical documentary sources, or seasonality measurements using climate data, remote sensing, flux measurements or modeling studies. Contributions across all spatial and temporal scales are welcome that compare and integrate seasonality changes, study effects of long-term climate change or single extreme events, emphasize applications and phenology informed decision-making, discuss species interactions and decoupling, advance our understanding of how seasonality change affects carbon budgets and atmosphere/biosphere feedbacks, and integrate phenology into Earth System Models.

We emphasize phenology informed applications for decision-making and environmental assessment, public health, agriculture and forest management, mechanistic understanding of the phenological processes, and effects of changing phenology on biomass production and carbon budgets. We also welcome contributions addressing international collaboration and program-building initiatives including citizen science networks and data analyses.

This session is organized by a consortium representing the International Society of Biometeorology (Phenology Commission), the Pan-European Phenology Network - PEP 725, the Swiss Academy of Science SCNAT, the TEMPO French Phenology Network and the USA National Phenology Network.

Large-scale atmospheric circulation dynamics are the major driver of near surface climatic and environmental variability. Synoptic climatology examines atmospheric circulation dynamics and their relationship with near surface environmental variables. Within synoptic climatological analyses, a wide variety of methods is utilized to characterize atmospheric circulation (e.g., circulation and weather type classification, regime analysis, teleconnection indices). Various linear and non-linear approaches (e.g., multiple regression, canonical correlation, neural networks) are applied to relate the circulation dynamics to diverse climatic and environmental elements (e.g., air temperature, air pollution, floods).

The session welcomes contributions from the whole field of synoptic climatology. This includes application studies for varying regions, time periods (past, present, future) and target variables and in particular contributions on the development and the comparison of methods (e.g., varying circulation type classifications) and conceptual approaches (e.g., circulation types versus circulation regimes).

As the most evident example of land use and land cover change, urban areas play a fundamental role in local to large-scale planetary processes, via modification of heat, moisture, and chemical budgets. With rapid urbanization ramping up globally it is essential to recognize the consequences of landscape conversion to the built environment. Given the capability of cities to serve as first responders to global change, considerable efforts are currently being dedicated across many cities to monitor and understand urban atmospheric dynamics and examine various adaptation and mitigation strategies aimed to offset impacts of rapidly expanding urban environments and influences of large-scale greenhouse gas emissions. 

This session solicits submissions from both the observational and modelling communities examining urban atmospheric and landscape dynamics, processes and impacts owing to urban induced climate change, the efficacy of various strategies to reduce such impacts, and techniques highlighting how cities are already using novel science data and products that facilitate planning and policies on urban adaptation to and mitigation of the effects of climate change. Emerging topics including, but not limited to, urban climate informatics, are highly encouraged.

The CL2.5 Session Solicited/Invited Talk will be given by Prof. Tony Brazel, recipient of the International Association of Urban Climate's Luke Howard Award, the American Meteorological Society's Helmut E. Landsberg Award, Lifetime Achievement Award of the Association of American Geographers' Climate Specialty Group, and the Jeffrey Cook Prize in Desert Architecture from Ben-Gurion University of the Negev, Israel.

Detecting and attributing the fingerprint of anthropogenic climate change in long-term observed climatic trends is an active area of research. Though the science is well established for temperature related variables, the study of other climate indicators including hydrometeorological variables pose greater challenges due to their greater complexity and rarity.

Complementary to this, assessing the extent to which extreme weather events, including compound events, are attributable to anthropogenic climate change is a rapidly developing science, with emerging schools of thought on the methodology and framing of such studies. Once again, the attribution of hydrometeorological events, is less straightforward than temperature-related events. The attribution of impacts, both for long-term trends and extreme events is even more challenging.

This session solicits the latest studies from the spectrum of detection and/or attribution approaches. By considering studies over a wide range of temporal and spatial scales we aim to identify common/new methods, current challenges, and avenues for expanding the detection and attribution community. We particularly welcome submissions that compare approaches, or address hydrometerological trends, extremes and/or impacts – all of which test the limits of the present science.

Public information:
This session was hosted as a zoom meeting. You can find the recording of the zoom meeting here : https://drive.google.com/file/d/18qSh8TkkNjSghvCAfe4EB5n0TKraXv7r/view?usp=sharing

High-impact climate and weather events typically result from the interaction of multiple hazards across various spatial and temporal scales. These events, also known as Compound Events, often cause more severe socio-economic impacts than single-hazard events, rendering traditional univariate extreme event analyses and risk assessment techniques insufficient. It is therefore crucial to develop new methodologies that account for the possible interaction of multiple physical drivers when analysing high-impact events. Such an endeavour requires (i) a deeper understanding of the interplay of mechanisms causing Compound Events and (ii) an evaluation of the performance of climate/weather, statistical and impact models in representing Compound Events.

The European COST Action DAMOCLES coordinates these efforts by building a research network consisting of climate scientists, impact modellers, statisticians, and stakeholders. This session creates a platform for this network and acts as an introduction of the work related to DAMOCLES to the research community.

We invite papers studying all aspects of Compound Events, which might relate to (but are not limited to) the following topics:

Synthesis and Analysis: What are common features for different classes of Compound Events? Which climate variables need to be assessed jointly in order to address related impacts? How much is currently known about the dependence between these variables?
Stakeholders and science-user interface: Which events are most relevant for stakeholders? What are novel approaches to ensure continuous stakeholder engagement?
Impacts: What are the currently available sources of impact data? How can they be used to link observed impacts to climate and weather events?
Statistical approaches, model development and evaluation: What are possible novel statistical models that could be applied in the assessment of Compound Events?
Realistic model simulations of events: What are the physical mechanisms behind different types of Compound Events? What type of interactions result in the joint impact of the hazards that are involved in the event? How do these interactions influence risk assessment analyses?

Precipitation is an essential aspect of climate, and also drives many climate impacts. The primary tool for projecting future precipitation is climate models. Climate models are already being used, both directly and indirectly, to quantify anticipated impacts of climate for the purpose of making decisions. Improving precipitation in models requires (1) quantifying characteristics of precipitation in relevant observational datasets, (2) comprehensive comparison of climate model precipitation against observations, and (3) sustained model development efforts focus on improving precipitation in models. It also requires addressing the many characteristics of precipitation, ranging from its mean spatial pattern through its variability across timescales from hourly and diurnal extending through extreme events (whether dry or wet).

We invite presentations in this session that address:
- metrics to quantify the characteristics of precipitation in observations,
- evaluation of climate model simulations against observations, and
- development efforts aimed at improving precipitation in models (including seamless modeling systems).

Public information:
Please have a look at the displays, leave a comment, and start a discussion!

The understanding of tropical phenomena and their representation in numerical models still raise important scientific and technical questions, particularly in the coupling between the dynamics and diabatic processes. Among these phenomena, tropical cyclones (TC) are of critical interest because of their societal impacts and because of uncertainties in how their characteristics (cyclogenesis processes, occurrence, intensity, latitudinal extension, translation speed) will change in the framework of global climate change. The monitoring of TCs, their forecasts at short to medium ranges, and the prediction of TC activity at extended range (15-30 days) and seasonal range are also of great societal interest.

The aim of the session is to promote discussions between scientists focusing on the physics and dynamics of tropical phenomena. This session is thus open to contributions on all aspects of tropical meteorology between the convective and planetary scale, such as:

- Tropical cyclones,
- Convective organisation,
- Diurnal variations,
- Local circulations (i.e. island, see-breeze, etc.),
- Monsoon depressions,
- Equatorial waves and other synoptic waves (African easterly waves, etc.),
- The Madden-Julian oscillation,
- etc.

We especially encourage contributions of observational analyses and modelling studies of tropical cyclones and other synoptic-scale tropical disturbances including the physics and dynamics of their formation, structure, and intensity, and mechanisms of variability of these disturbances on intraseasonal to interannual and climate time scales.

Findings from recent field campaigns such as YMC and PISTON are also encouraged.

The Andes is the longest cordillera in the world and extends from northern South America (11°N) to the southern tip of the continent (∼53°S). The Andes runs through seven countries and provide resources for about 90 million inhabitants. The Andes is characterized by a rich variety of mountain climates and ecosystems, producing unique contrasting climate conditions over its eastern and western sides, but also across its latitudinal extent. Currently, the Andes hydroclimate faces several threats to sustainable development, such as water supply and the sustainability of ecosystem services, including global climate change, Andes and Amazon deforestation and local land use change, glaciers retreat, human encroachment, among others). In turn, diverse hydroclimatic high-impact extreme events affect the Andean communities owing to the prevailing weather and climate patterns, steep terrain, deforestation and human occupancy. This session aims to assess and discuss recent progress in the Andes hydroclimate and identify pressing research challenges and the development of associated human capabilities. We welcome submissions based on observational and modelling approaches, from the local to the continental scales and from diurnal to interdecadal time scales. Emerging new topics are particularly welcome, including water and energy budgets, high impact events, precipitation hotspots, climate change and deforestation impacts, climate-vegetation interactions, cryosphere studies, water resources availability, connections with the Amazon and the La Plata River basins and neighboring oceans, among others.

Public information:
Additional information:
i) This session will be divided into two sub-sessions:
1) Climatology and Atmospheric Sciences, and
2) Hydrology and Water Resources.

The session schedule is available at : (https://meetingorganizer.copernicus.org/EGU2020/sessionAssets/36767/materials.pdf)

ii) Each sub-session will be divided into blocks.
iii) The authors introduce themselves (following the order of the presentations) and provide a couple of sentences summarizing their main result/highlight/discussion topic.
iv) At the end of each block, we dedicate a few minutes to questions from the audience. Each block, including the questions, lasts 10 minutes.
v) We will spend a few minutes on the general discussion and conclusion.

Clouds and aerosols play a key role in climate and weather-related processes over a wide range of spatial and temporal scales. An initial forcing due to changes in the aerosol concentration and composition may also be enhanced or dampened by feedback processes such as modified cloud dynamics, surface exchange or atmospheric circulation patterns. This session aims to link research activities in observations and modelling of radiative, dynamical and microphysical processes of clouds and aerosols and their interactions. Studies addressing several aspects of the aerosol-cloud-radiation-precipitation system are encouraged.

Topic covered in this session include:
- Cloud and aerosol macro- and microphysical properties, precipitation formation mechanisms
- The role of aerosols and clouds for the radiative energy budget
- Observational constraints on aerosol-cloud interactions
- Cloud-resolving modelling
- Parameterization of cloud and aerosol microphysics/dynamics/radiation
- Use of observational simulators to constrain aerosols and clouds in models
- Experimental cloud and aerosol studies
- Aerosol, cloud and radiation interactions and feedbacks in the climate system

Invited Speakers:
Nicolas Bellouin (University of Reading)
Anna Possner (Goethe University Frankfurt)

With the rapidly changing conditions in the Arctic and Antarctic, reliable weather and climate forecasts are becoming increasingly important in the polar regions due to new challenges and opportunities in the economic, touristic, transportation, and scientific sectors. Likewise, the weather and climate of the mid-latitudes are significantly affected by what happens at the poles. While the impacts of severe weather phenomena on business and infrastructure can be significant, the polar regions are yet among the least-observed areas of our planet, and model predictions are challenged by the complexity of the polar climate systems.
To enhance our models’ predictive skills, more and better use of observation systems of the polar atmosphere, sea ice, and ocean are needed. It is on these premises that the World Meteorological Organization’s project Year of Polar Prediction (YOPP) and the European Horizon2020 APPLICATE project are carrying out their activities, initiating and promoting collaboration among international institutes, operational forecasting centers and stakeholders in an effort to bring together scientific expertise and know-how to work on better polar predictive skill.
In this session, we welcome presentations on activities and results from the YOPP and APPLICATE projects as well as contributions from other projects and institutes that focus on how to best capitalise on existing and additional Arctic and Antarctic observations such as Copernicus to improve forecast initial states, verification, and model physics, and to optimise the future polar observing system.
We welcome abstracts on topics including, but not limited to: Arctic and Antarctic observations, modelling, prediction, data assimilation, verification, linkages to mid-latitudes, user engagement, and governance. New results, contributions from international projects with a focus in the polar regions, and cross-disciplinary approaches that involve natural and social sciences are particularly appreciated.

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.

Public information:
16:15-16:50 Characteristics of Polar Seas and connection with ice shelves and the open ocean
Chairs: Leo, Louis

16:15-16:20 Raquel Flynn (D2761 | EGU2020-21107)
16:20-16:25 Katherine Hutchinson (D2768 | EGU2020-112)
16:25-16:30 Roberto Grilli (D2772 | EGU2020-2984)
16:30-16:35 Chengyan Liu (D2770 | EGU2020-2319)
16:35-16:40 Ria Oelerich (D2763 | EGU2020-463)
16:40-16:45 Ute Hausmann (D2767 | EGU2020-22464)
16:45-16:50 General Discussion

16:50-17:20 Sea ice and its interaction with ice shelves and the Southern Ocean
Chairs: Nadine, Xylar

16:50-16:55 Lucile Ricard (D2765 | EGU2020-17820)
16:55-17:00 Pierre-Vincent Huot (D2780 | EGU2020-19677)
17:00-17:05 Isabelle Giddy (D2777 | EGU2020-9934)
17:05-17:10 F. Alexander Haumann (D2782 | EGU2020-22008)
17:10-17:15 Sönke Maus (D2762 | EGU2020-6039)
17:15-17:20 General Discussion

17:20-18:00 Turbulent Ice Shelf-Ocean Boundary Layers
Chairs: Irena, Xylar

17:20-17:25 Ryan Patmore (D2769 | EGU2020-10388)
17:25-17:30 Leo Middleton (D2781 | EGU2020-9112)
17:30-17:35 Louis-Alexandre Couston (D2776 | EGU2020-19054)
17:35-17:40 Carolyn Branecky Begeman (D2774 | EGU2020-10848)
17:40-17:45 Peter Davis (D2771 | EGU2020-50)
17:45-18:00 General Discussion

It has been shown that regional climate change interacts with many other man-made perturbations in both natural and anthropogenic coastal environments. Regional climate change is one of multiple drivers, which have a continuing impact on terrestrial, aquatic and socio-economic (resp. human) environments. These drivers interact with regional climate change in ways, which are not completely understood. Recent assessments all over the world have partly addressed this issue (e.g. Assessment of Climate Change for the Baltic Sea region, BACC (2008, 2015); North Sea Climate Change Assessment, NOSCCA (2011); Canada’s Changing Climate Report, CCCR (2019)).
This session invites contributions, which focus on the connections and interrelations between climate change and other drivers of environmental change, be it natural or human-induced, in different regional seas and coastal regions. Observation and modelling studies are welcome, which describe processes and interrelations with climate change in the atmosphere, in marine and freshwater ecosystems and biogeochemistry, coastal and terrestrial ecosystems as well as human systems. In particular, studies on socio-economic factors like aerosols, land cover, fisheries, agriculture and forestry, urban areas, coastal management, offshore energy, air quality and recreation, and their relation to climate change, are welcome.
The aim of this session is to provide an overview over the current state of knowledge of this complicated interplay of different factors, in different regional seas and coastal regions all over the world.

This session will focus on variability in the ocean and its role in the wider climate system using both observations and models. Areas to be considered will include both ocean heat uptake and circulation variability as well as exploring the use of sustained ocean observing efforts and models to make progress in understanding the ocean’s role in the climate system. More than 90% of the excess heat in the climate system has been stored in the ocean, which mitigates the rate of surface warming. Better understanding of ocean ventilation mechanisms, as well as the uptake, transport, and storage of oceanic heat are therefore essential for reducing the uncertainties on global warming projections. Circulation variability and connectivity, particularly from the South Atlantic to the North Atlantic and Arctic Ocean, are also of interest as well as how they are driven by local-, large- or global-scale processes or teleconnections. Sustained observations at sea are being made within a wide variety of programmes and are leading to significant advances in our ability to understand and model climate. Thus, this session will also explore ongoing and planned sustained ocean observing efforts and illuminate their roles in improving understanding of the ocean’s role in the climate system. For example, air-sea flux moorings are being maintained at select sites to assess models and air-sea flux fields. Deep temperature and salinity measurements are being made at time series moorings and will be made by deep Argo floats. Significant advances are also being made using Argo floats for biogeochemistry and carbon measurements. Such observations provide the means to develop linkages between sustained ocean observing and climate modelling. In conclusion, the session will consider key aspects of ocean variability and its climate relevance, as well as encouraging the use of observations and models to enhance understanding of these areas.

Public information:
Announcement: We'll host a webinar with speakers from our session next week. May 13., 15:00-18:30 CEST

Agenda for the webinar: http://iacweb.ethz.ch/staff/medhaugi/files/UnofficialEGUOS1p6ZoomMeetingProgramme.pdf.

The webinar will be open to everyone, but please sign up to receive login details: https://forms.gle/6qwNVrBq7aYc7pn78

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).

Public information:
Session structure file is back.

Yevegny

Observations and model simulation illustrate significant ocean variability and associated air-sea interactions from regional to global scale and on diurnal to inter-annual time scales. This session is devoted to the understanding of the tropical and subtropical ocean dynamics, its interaction with the overlying atmosphere from the equator to mid-latitudes and its climate impacts on adjacent to remote areas.
Relevant processes in the ocean include upper and deep ocean circulation, mild SST gradients to sharp fronts, eddies, filaments, tropical instability waves, warm pools, cold tongues and eastern boundary upwellings. Furthermore, we are interested in air-sea interactions related to both the seasonal cycle and the development of modes of variability from local to basin scale. Wind variations related to Madden-Julian Oscillation, cyclones, and convective systems, as well as those leading the air-sea coupled modes (e.g., the Meridional Mode and Atlantic Niño) are welcome. Finally, we also seek contributions examining the causes and impacts of systematic model errors in simulating the local to regional climate.
Studies based on direct observations, reanalysis, reconstructions as well as model simulations are welcome.

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.