WCRP-WWRP Symposium on Data Assimilation and Reanalysis and 2021 ECMWF Annual Seminar on Observations

Due to the pandemic, the WCRP-WWRP Symposium on Data Assimilation and Reanalysis will now be held fully virtual, 13-18 September 2021 alongside the 2021 ECMWF Annual Seminar on Observations. The event is kindly organized by Deutscher Wetterdienst (DWD).

Due to the recently announced change from a hybrid format to a fully virtual event, we would like to give potential contributors some time to consider submitting abstracts for the WCRP-WWRP Joint Symposium on Data Assimilation and Reanalysis under the new format. Therefore, the deadline for submission of abstracts is extended to 7 May 2021.

Objectives of the WCRP-WWRP symposium

The overall objective of WCRP-WWRP Symposium on Data Assimilation and Reanalysis, with local organisation let by DWD is to review latest developments and address issues of common interest to data assimilation and reanalysis communities, such as Earth system and coupled approaches, ensemble techniques and covariances, process studies, handling of systematic errors, diagnostics and verification, emerging AI and Machine learning techniques, open science and collaborative platforms. The Symposium will build on the programme of the Annual Seminar focusing on an Earth system view of observations.

The timing of sessions in the two meetings will be optimised to allow attendees to enjoy both events as much as possible, and to allow the attendees to mingle and share their knowledge.

The joint events offer great opportunities to bring Earth system data assimilation, reanalysis and observations impact communities together to identify current challenges and seek opportunities for collaboration and strategic planning on a more integrated Earth system value-chain approach on the longer term.   

The conference will feature a number of plenary and parallel oral sessions, as well as poster sessions, complemented by various Early Career Scientist activities and panel discussions.

The main following topics will be covered during the symposium :

Center Updates
Contributions could for example address: updates from operational centers on DA, updates from global and regional reanalysis producers

Contributions could for example address: ensemble approaches, non-linear/non-Gaussian DA, AI approaches, innovative approaches to reanalysis, satellite DA (e.g., hyper-spectral), radar DA (e.g., dual-polarization, volumetric), DA on the km-scale and lower, ultra-rapid DA, preparing for the exascale, Ocean DA

Earth System Modelling
Contributions could for example address: coupled DA (e.g., with land surface, ocean ice), bio-geochemistry modelling, seamless approaches - from minutes to seasons / multi-scale aspects, atmospheric composition

Contributions could for example address: observations for paleo simulations (e.g., ocean, atmosphere, cryosphere), continuity of observations, crowd-sourcing and unconventional observations, data rescue efforts, remote sensing for the boundary layer

Contributions could for example address: extreme events and high-impact weather in forecasting and reanalysis, renewable energy, hydrology, socio economic applications (e.g., health, agriculture)

Verification / Evaluation / Post-Processing
Contributions could for example address: metrics and diagnostics, observations for evaluation, avoiding discontinuities in reanalysis, surface reanalysis

Contributions could for example address: upcoming reanalyses, developments in DA infrastructures, shared assimilation infrastructure to advance science, DA and reanalysis in education, knowledge transfer, technology for user-oriented reanalysis dissemination, research to operations



  • The programme as of 13 Sep. is available here
  • The book abstracts is available here



  • 24 March: call for abstracts 
  • 7 May: new deadline for abstracts submission
  • 30 June: notification to applicants - Postponed to 16 July
  • 28 July: preliminary programme
  • 30 August: final programme
  • 9 September: registration closed
  • 13-18 September: symposium
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