EGU General Assembly 2020

The EGU has officially announced the cancellation of the physical EGU General Assembly 2020 in Vienna, Austria. They have therefore decided to host EGU2020: Sharing Geoscience Online (#shareEGU20), a week-long series of online activities held during the first week of May that support the community by fostering scientific communication.

EGU2020: Sharing Geoscience Online will allow abstract authors to share presentation materials and open these for live discussion as well as participate in a selection of online networking events. They are also planning additional activities that will extend into the rest of the year and will provide more information about all of these events in the coming weeks.

EGU2020: Sharing Geoscience Online

EGU2020: Sharing Geoscience Online will allow abstract authors to share presentation materials and open these for live discussion. Organizers are also planning additional activities and will provide more information about all of these events in the coming weeks. Please take a look at the EGU2020: Sharing Geoscience Online page: https://egu2020.eu/sharing_geoscience_online.html

The central platform for presentation hosting and commenting will be EGUsphere, the new EGU interactive community platform: https://www.egusphere.net/

Please follow the EGU official website and the EGU's social media accounts (Tw: @EuroGeosciences) using the official hashtags #EGU20 and #shareEGU20 for more information.

What exactly happens from 4–8 May and is there anything taking place beforehand?

Scientific sessions encourage the upload of presentation materials from 1 April to 31 May. The same period is valid for comments by the community and replies by the authors. Please use these two months for a continued exchange. Then, during the EGU2020: Sharing Geoscience Online week from 4–8 May, scientific sessions offer a text-based live chat during the sessions' allocated time blocks. This chat is in addition to the two-month exchange period. The text-based live chat does neither involve live presentations nor video or audio chats, in order to remain inclusive for all attendees. The text-based chat is an opportunity for attendees of a session to discuss the uploaded presentation materials and abstracts of that session.

Preparations

Watch a webinar from the EGU Programme Committee about how "EGU Sharing Geoscience Online" is going to work: https://www.youtube.com/watch?v=mzCoG93xQak

EGU Sharing Geoscience Online comprises two separate functions:

1. The possibility for authors to upload display material to their abstract, to opt in on welcoming online comments, and to engage in online discussion:
- This happens on EGUsphere (https://www.egusphere.net/conferences/EGU2020/index.html) between 1 April and 31 May,
EGUsphere is EGU’s new pre-print journal/repository;
- Online commenting on abstracts and their displays (if uploaded) is restricted to EGU Members (after logging in);
- The discussion material will remain available also after 31 May, protected by the doi given to your abstract.

2. The possibility to join the online text-based live chat session during which the chat participants can exchange written comments about the abstracts and/or uploaded display material:
- This happens in EGU week, between 4 and 8 May, during a fixed, programed time slot;
- This happens on a different platform than EGUsphere (to be communicated later);
- It is open to anyone;
- The chat will be moderated by session conveners;
- The chat content will not be archived, i.e. will be erased when the chat session closes.

PAGES working group chat sessions - all times in CET (UTC+2)

i. 2k Network: CL1.18 Studying the climate of the last two millennia (Session ID: 36726) Friday 8 May, 08:30–12:30
Convener: Sarah S. Eggleston. Co-conveners: Stella Alexandroff, Hugo Beltrami, Oliver Bothe, Andrea Seim

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.

ii. ACME: CR7.1 Cryosphere change impacts on marine ecosystems and biogeochemical cycling - bridging reconstructions, observations and modelling (Session ID: 34970) Thursday 7 May, 16:15–18:00
Convener: Sofia Ribeiro. Co-conveners: Mark Hopwood, Anna Pienkowski, Letizia Tedesco

Decreasing sea-ice coverage, increasing permafrost-derived inputs and increasing glacier discharge will continue to affect the Arctic Ocean region in coming decades under all future climate scenarios. Such changes at the interface between the ocean and the cryosphere across the Arctic basin raise questions about the downstream effects in marine ecosystems, particularly with respect to ecosystem services such as fisheries and carbon sequestration. In order to understand the effect of changing cryosphere-derived inputs on the Arctic marine environment, 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.

iii. CVAS: CL4.2 Future insights from a constantly varying past, and climate variability across scales (Session ID: 36761) Friday 8 May, 14:00–15:45
Convener: Julia Hargreaves. Co-conveners: Kira Rehfeld, Thomas Laepple, Shaun Lovejoy

State of the art climate models are now run for past, present and future climates. This has opened up the opportunity for paleoclimate modeling 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.

iv. Floods Working Group: HS2.4.2 Extreme hydrological events of the Past (Session ID: 35539) Thursday 7 May, 14:00–15:45
Convener: Juan Pablo Corella. Co-conveners: Juan Antonio Ballesteros, David Barriopedro Cepera, Bruno Wilhelm

Extreme hydrological events disasters such as droughts, floods and storms lead to the most devastating natural in terms of casualties and economic losses. In the context of current global warming, there is a high uncertainty on the observed trends and projected changes in extremes at a global scale. Extreme events that occurred in the past play here an important role as they enable us to investigate the dynamics of extremes under natural climate variability beyond the instrumental period.

The main goal of this session is to bring together scientist, scholar and engineers that explore the variability and controlling mechanisms of past hydrological extremes on decadal to millennial time-scales based on different historical and natural archives such as tree-rings, speleothems, lacustrine and marine sediments and ice cores. We also welcome contributions that integrate both, proxy data and climate modelling to understand the external and internal forcing controlling the hydrological cycle. We also invite contributions that explore new statistical modelling approaches aiming to quantitatively assess the climate drivers of the non-stationary behaviours of extreme events frequency and intensity.

v. LandCover6k: BG3.32 Holocene land-use and land-cover change: advances and applications - from quantifying vegetation change to estimating human impacts on biodiversity (Session ID: 35254) Thursday 7 May, 10:45–12:30
Convener: Jessie Woodbridge. Co-conveners: Ralph Fyfe, Petr Kunes, Furong Li

The world has been significantly transformed by human actions at least throughout the course of the Holocene with implications for ecological functioning, climate regulation, etc. Central to furthering understanding of the timing, extent and impact of these transformations is quantification of vegetation cover and land-use at local, regional and continental scales, and at centennial to millennial timescales. Recent accelerations in the intensity of human land use have been implicated for changes in biodiversity, however, relationships between land use change and diversity are complex and include important historical legacies. This session explores recent developments in, and applications of, the quantification of land-cover and land-use from palaeobotanical and palynological data in globally diverse landscapes. We welcome all contributions on methodological advances, and applications to historic and prehistoric long-term dynamics and drivers of land-use, anthropogenic land-cover and land-system change, as well as shifts in biodiversity patterns. These contributions may include pollen and other palaeobotanical approaches to land-use and land-cover change, archaeological and historical records and related palaeoecological data (e.g. palaeoentomological data), as well as modelling studies on anthropogenic land-cover change (ALCC) and climate-land use interactions.

This session contributes to the PAGES LandCover6k working group. The primary goal of LandCover6k is to use global empirical data on past land-use and anthropogenic land-cover change to evaluate and improve Anthropogenic Land-Cover Change scenarios for earth system modellers (e.g. the World Climate Research Programme CMIP and PMIP initiatives). However, submissions do not need to be explicitly linked to this working group and we welcome abstracts with wider reaching themes spanning environmental responses to human activities, such as biodiversity loss and changes in ecosystem functioning.

vi. PALSEA: SSP1.2 New and re-interpreted Pleistocene sea-level records from around the Globe (Session ID: 36473) Wednesday 6 May, 08:30–10:15
Convener: Deirdre Ryan. Co-conveners: Victor Cartelle, Kim Cohen, Alessio Rovere

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.

vii. VICS: ITS2.13/AS4.29 Characterizing, understanding, predicting the radiative effects of major volcanic eruptions and their impacts on climate and societies (Session ID: 35738) Wednesday 6 May, 08:30–12:30
Convener: Myriam Khodri. Co-conveners: Claudia Timmreck, Davide Zanchettin, Graham Mann, Matthew Toohey

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 associated with volcanological 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.

This session aims to highlight new results from integrative research on the climatic response to volcanic eruptions of Pinatubo-magnitude and larger, with a special focus on studies conducted under the umbrella of the CMIP6, in particular the VolMIP activity. This session invites contributions that explore the responses of the coupled ocean-atmosphere system to volcanic forcing, from the characterization of past volcanically-forced climate variability, particularly during the Common Era, and on the identification of dominant mechanisms of interannual-to-interdecadal volcanically-forced variability by means of observations, climate reconstruction studies as well as modeling approaches.

This session also welcomes presentations contributing to current international SPARC-SSiRC and PAGES-VICS activities from research aimed at better understanding the stratospheric aerosol layer, its volcanic perturbations and impacts on historical and modern societies. We further invite observational and modelling studies of the 2019 Raikoke aerosol cloud, from recent field campaigns and contributions on the potential role of volcanic eruptions on future climate variability and predictability.

Former working group session

i. GPWG2: Highlight: What paleofire records can say about the present and future of fire on Earth (D575) Wednesday 6 May, 14:00–15:45
Jennifer Marlon, Anne-Laure Daniau, Patrick Bartlein, and Andry Rajaoberison

Sedimentary charcoal records typically provide information about variations in wildfire activity over thousands of years, and a few even span millions of years. Such long, continuous measurements of combustion products offer a rare opportunity to understand the response of fire to both rapid and gradual climate forcings, whether from human-caused global warming, volcanic activity, atmosphere-ocean circulation changes, or Milankovitch cycles. Here we use paleofire records from the Global Charcoal Database to demonstrate the dynamic nature of wildfire activity in response to varied forcings, particularly the role that relatively small temperature and precipitation shifts have on patterns of burning across space and time. Paleodata from areas currently experiencing severe wildfires are also examined in order to provide context for events that appear unprecedented in modern times.

(This forms part of BG3.17 The Role of Fire in the Earth System: Understanding Interactions with the Land, Atmosphere, and Society (Session ID 35224) Wednesday 6 May, 14:00-18:00)

Endorsed group session

i. Varves Working Group: CL5.1 Geochronological tools for environmental reconstructions (Session ID: 36764) Wednesday 6 May, 08:30–10:15
Convener: Irka Hajdas. Co-conveners: Andreas Lang, Gina E. Moseley, Arne Ramisch

During the Quaternary Period, the last 2.6 million years of Earth's history, changes in environments, and climate shaped human evolution. In particular, large-scale features of atmospheric circulation patterns varied significantly due to the dramatic changes in global boundary conditions that accompanied abrupt changes in climate. Reconstructing these environmental changes relies heavily on precise and accurate chronologies. Dependent on records, time range, and research questions, different methods can be applied, or a combination of various dating techniques. Varve counting and dendrochronology allow for the construction of high-resolution chronologies, whereas radiometric methods (radiocarbon, cosmogenic in-situ, U-Th) and luminescence aim at longer time scales and often are complementary or supportive.

In this session, contributions are particularly welcome that aim to (1) reduce, quantify and express dating uncertainties in any dating method, including high-resolution radiocarbon approaches; (2) use established geochronological methods to answer new questions; (3) use new methods to address longstanding issues, or; (4) combine different chronometric techniques for improved results, including the analysis of chronological datasets with novel methods, e.g. Bayesian age-depth modelling. Applications may aim to understand long-term landscape evolution, quantify rates of geomorphological processes, or provide chronologies for records of climate change.

Short course

i. CVAS: SC1.16 Estimating trends and variability from paleoclimate proxy records (Session ID: 36352)
Convener: Nils Weitzel. Co-conveners: Raphael Hébert, Kira Rehfeld

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

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

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

Further information

Go to the official EGU 2020 website: https://www.egu2020.eu/