International Symposium on Data Assimilation - Online


  • Date: January 2021 - February 2022, October 2022 - June 2023, January 2024 -
  • Place: Online
  • Language: English


The International Symposium on Data Assimilation - Online (ISDA-Online) is a seminar series on the topic of Data Assimilation.

The 8th ISDA that was planned at Colorado State University for the summer of 2020 had to be postponed until the year 2022 due to Corona. In the meantime, the ISDA-Online seminar series provides a monthly platform for the exchange of new and exciting data assimilation research.

We, RIKEN Data Assimilation Research Team, publish recorded videos as a co-organizer.

Please see the details of the symposium at the main organizer's web site: ISDA-Onlie (University of Vienna).

Presentations in 2024

Mar. 8, 2024: Topic: Advancements in Ensemble Data Assimilation

Presenter Title Video
Eviatar Bach, Tim Colonius, Isabel Scherl, Andrew Stuart Filtering Dynamical Systems Using Observations of Statistics Youtube
Hao-Lun Yeh, Peter Jan van Leeuwen Unbiased fully nonlinear data assimilation: the Stochastic Particle Flow Filter Youtube
Vikrant Gupta, Minping Wan, Francesco Fossella, Luca Biferale, Massimo Cencini, Alberto Carrassi, Chunxue Yang DA for multi-time and multi-scale models of the turbulent energy cascade Youtube
Michael Tsyrulnikov, Arseniy Sotskiy Regularization of the ensemble Kalman filter using a non-stationary, non-parametric spatial model Youtube
Mohamad Abed El Rahman Hammoud, Naila Raboudi, Edriss S. Titi, Omar Knio, Ibrahim Hoteit Nonlinear Data Assimilation in Chaotic Systems Using Deep Reinforcement Learning N/A

Feb. 2, 2024: Topic: Advancements in Variational Data Assimilation

Presenter Title Video
Marc Bocquet Bridging classical variational data assimilation and optimal transport Youtube
Olivier Goux Accounting for correlated observation error in variational ocean data assimilation Youtube
Arthur Filoche Data assimilation as variational inference. Full posterior estimation using the 4DVAR cost Youtube
Tracy Scanlon Deviation of skin increments using all-sky microwave observation for use in a coupled atmosphere-ocean system Youtube
Ziga Zaplotnik Towards higher resolution data assimilation in ECMWF IFS Youtube

Jan. 12, 2024: Topic: Machine Learning in Data Assimilation

Presenter Title Video
Alan Geer Combining machine learning and data assimilation at ECMWF Youtube
Stephan Rasp The second revolution in numerical weather prediction and its implications for data assimilation Youtube
Ronan Fablet End-to-end neural data assimilation: from toy examples to uncertainty quantification with real ocean data Youtube

Presentations in 2023

Jan. 20, 2023: Non-Gaussian Data Assimilation

Presenter Title Video
Jeff ANDERSON A Quantile Conserving Ensemble Filtering Framework: Regressing Probit-Transformed Quantile Increments to Update Unobserved Variables Youtube
Hristo G. CHIPILSKI, Ian Grooms, Mohamad El Gharamti, Jeffrey Anderson, Ricardo Baptista Revisiting and Repurposing the Gaussian Anamorphosis EnKF Youtube
Ian GROOMS A two-step nonlinear non-Gaussian framework for data assimilation applied to assimilation of wind direction observations Youtube
Yue (Michael) YING, Jeffrey Anderson, Laurent Bertino Improving vortex position accuracy with a new multiscale alignment ensemble filter Youtube
Patrick N. RAANES "Ensemblized" linear least squares (LLS) N/A

Feb. 10, 2023: Ocean Data Assimilation

Presenter Title Video
Norihisa Usui, Yosuke Fujii, Nariaki Hirose, Ichiro Ishikawa Improvement of the Ocean 4D-Var Scheme for High-Accuracy Sea Surface Temperature Analysis and Forecast Youtube
Nabir Mamnun, Christoph Völker, Mihalis Vrekoussis, Lars Nerger Estimation of Spatially and Temporally Varying Biogeochemical Parameters in a Global Ocean Model Youtube
Svetlana N. Loza, Marylou Athanase, Longjiang Mu, Jan Streffing, Miguel Andrés-Martínez, Lars Nerger, Tido Semmler, Dmitry Sidorenko, Helge F. Goessling Predicting the Sea-Ice and Ocean State by Combining Sea-Ice and Ocean Data Assimilation with Atmospheric Wind Nudging Youtube
Tsz Yan Leung, Amos S. Lawless, Nancy K. Nichols, Daniel J. Lea, Matthew J. Martin The Impact of Hybrid Oceanic Data Assimilation in a Coupled Model: A Case Study of a Tropical Cyclone N/A
Zofia Stanley, Clara Draper, Sergey Frolov, Laura Slivinski, Wei Huang, Jeffrey Whitaker, Henry Winterbottom Guidance on Localization for Strongly Coupled Atmosphere-Ocean Data Assimilation Youtube

Mar. 3, 2023: Operational Data Assimilation

Presenter Title Video
Yoshiaki Sato Current status and Future Prospects of Data Assimilation Systems for Operational Numerical Weather Prediction Systems in Japan Meteorological Agency N/A
(The link is available upon request to the ISDA-Online organizers.)
Florence Rabier Developments and prospects for the ECMWF Data Assimilation system Youtube

May. 12, 2023: Satellite Data Assimilation II

Presenter Title Video
Indira Rani Use of satellite data in an operational NWP Data Assimilation System Youtube
Annika Schomburg, Christoph Schraff, Liselotte Bach, Robin Faulwetter, Christina Köpken-Watts Towards the operational assimilation of all-sky water vapour SEVIRI channels in our regional ensemble Kalman filter assimilation system Youtube
Xin Li, Xiaolei Zou Several Measures for Improving the CrIS All-sky Infrared Radiance Assimilation Youtube
Samuel K. Degelia, Xuguang Wang Assimilation of GOES-16 ABI all-sky radiance observations in RRFS using hybrid EnVar: Development and impacts for a severe convective event Youtube

Jun. 2, 2023: Topic: Parameter Estimation & Inverse Modelling

Presenter Title Video
Shunji Kotsuki, Takumi Saito, Mao Ouyang, Daiya Shiojiri Combining Data Assimilation and Data-driven Sparse Sensing Placement Method For Designing Better Observation Locations Youtube
Martin Vojta, Andreas Plach, Rona L. Thompson, Andreas Stohl Critical remarks on inverse modeling techniques Youtube
Luca Cantarello, Nicolas Bousserez, Panagiotis Kountouris, Massimo Bonavita, Richard Engelen Data assimilation developments for a new emission inversion system at ECMWF Youtube
Alan Geer Simultaneous inference of sea ice state and surface emissivity model using machine learning and data assimilation Youtube
Yohei Sawada, Le Duc An Efficient Estimation of Time-Varying Parameters of Dynamic Models by Combining Offline Batch Optimization and Online Data Assimilation Youtube
Sujeong Lim, Seon Ki Park, Claudio Cassardo Parameter estimations in Land Surface Model Youtube

Presentations in 2022

Jan. 14, 2022: Data Assimilation Infrastructure - Software, Frameworks, HPC

Presenter Title Video
Moha Gharamti The Data Assimilation Research Testbed in 2022 and Beyond: Not Your Parents' DART Youtube
Hisashi Yashiro A global 3.5km-mesh 1024-member ensemble data assimilation benchmark - Our challenges on the supercomputer Fugaku N/A
Arata Amemiya 1000-member 30-second-update real-time precipitation forecast experiment using the supercomputer Fugaku Youtube
Sebastian Friedemann Melissa-DA: An Elastic and Fault Tolerant Large-Scale Online Data Assimilation Framework Youtube
Chao Sun Developing a common, flexible and efficient framework for weakly coupled ensemble data assimilation based on C-Coupler2 Youtube
Lars Nerger PDAF - community software for ensemble-based data assimilation Youtube

Feb. 11, 2022: History of Data Assimilation

Presenter Title Video
Olivier Talagrand A Brief History of Data Assimilation Youtube
Michael Ghil Data Assimilation: From an Eventful Past to a Bright Future Youtube

Oct. 7, 2022: Reanalysis

Presenter Title Video
Sergey Frolov Findings from the CLIVAR workshop on future U.S. earth system reanalysis efforts Youtube
Lucie Bakels A Lagrangian translation of the ERA-5 re-analysis Youtube
Andrea Storto Towards systematic inter-comparison of ocean reanalyses and statistical mapping methods for long-term ocean heat content estimation Youtube
Kevin Raeder A CESM+DART Atmospheric Reanalysis for Forcing Ocean, Land, and Other Surface Models Youtube
Shun Ohishi LETKF-based Ocean Research Analysis (LORA) in the Western North Pacific region Youtube
Hao Zuo A preliminary evaluation of the ECMWF ORAS6 ocean and sea-ice reanalysis with ensemble ocean DA system Youtube

Nov. 4, 2022: Observation Impact

Presenter Title Video
Katrin Lonitz Running Ensemble of Data Assimilation Experiments - using GNSS-RO and MW sounding data Youtube
Bruce Ingleby Seasonality of the impact of stratospheric observations at high latitudes Youtube
Erica L. McGrath-Spangler Impacts of Assimilating Infrared Sounders from Geostationary Orbit Youtube
Gimena Casaretto Ensemble Forecast Sensitivity to Observations Impact (EFSOI) applied to a regional data assimilation system over Argentina Youtube
Philipp Griewank Using ensemble sensitivities to estimate the benefit of wind lidars Youtube
Olaf Stiller Covariance based impact diagnostics for cross-validating the consistent use of different observation types Youtube

Dec. 2, 2022: Land-Surface Data Assimilation

Presenter Title Video
Kenta Ochi Recent activities on snow data assimilation for NWP and reanalysis at ECMWF Youtube
Sujeong Lim, Seon Ki Park, Milija Zupanski Assimilation Impacts of SMAP Soil Moisture Retrievals within Strongly Coupled Atmosphere-Land Surface Data Assimilation System N/A
Yohei Sawada Ecohydrological land reanalysis by assimilating satellite microwave observations into a land surface model Youtube
Akhilesh S. Nair Improving sub-seasonal prediction skill of NorCPM using soil moisture assimilation Youtube
Brett Raczka Improving the Representation of Land Surface Processes using the Data Assimilation Research Testbed (DART) Youtube
Michel Bechtold Improving streamflow simulation by assimilating Sentinel-1 backscatter into a land surface model with river routing Youtube

Presentations in 2021

Jan. 8, 2021: Data Assimilation Methods

Presenter Title Video
Roland Potthast Feature Data Assimilation - Theory, Algorithms and Examples Youtube
Xinfeng Gao Space-Time Multigrid for the Maximum Likelihood Ensemble Filter Method Youtube
Oliver Guillet A method for representing spatially correlated observation errors for wind data Youtube
Flavia Pinheiro Efficient nonlinear data assimilation using synchronization in a particle filter Youtube
Jeff Whitaker Understanding the differences between EnVar and LETKF solvers in an operational NWP setting Youtube

Feb. 5, 2021: Satellite Data Assimilation

Presenter Title Video
Yasutaka IKUTA Assimilation of GPM DPR Spectral Latent Heating using Vertical Correlated Observation Error Covariance in Kalman Gain Youtube
James Taylor Oversampling Reflectivity Observations from a Geostationary Precipitation Radar Satellite: Impact to Typhoon Forecasts within a Perfect Model OSSE Framework Youtube
Renaud Hostache A tempered particle filter for jointly assimilating satellite soil moisture and flood extent maps into a flood inundation model Youtube
Jyoti Bhate Role of Scatterometer Data Assimilation in the simulation of boundary layer flow of tropical cyclones Youtube
Marta Janisková Experimental assimilation of space-borne cloud radar and lidar observations directly in the 4D-Var system used at ECMWF Youtube

Mar. 12, 2021: Mathematics of Data Assimilation

Presenter Title Video
Rebecca Atkinson Mitigating Sampling Error using Optimal Localisation in Ensemble Data Assimilation Youtube
Ricardo Baptista Ensemble-based data assimilation via nonlinear couplings Youtube
Shay Gilpin Continuum Covariance Propagation for Understanding Variance Loss in Advective Systems Youtube
Geir Evensen A subspace iterative ensemble smoother for solving DA and inverse problems Youtube
Jonathan Poterjoy High-dimensional Data Assimilation using Regularization and Iterative Resampling with the Local Particle Filter Youtube

Apr. 16, 2021: Convective-Scale Data Assimilation

Presenter Title Video
Joshua McCurry Exploring Particle Filtering Strategies for Convective-scale Weather Forecasting Youtube
Tadashi Fujita Assimilation of Radial Winds with Observation Error Correlated in Time and Space Youtube
Leonhard Scheck Using visible satellite images in convective-scale data assimilation Youtube
Pauline Combarnous An observation operator for geostationary lightning imager data assimilation in storm-scale numerical weather prediction systems Youtube
Pierre Brousseau AROME-France 4DEnVar: A data assimilation system for NWP at convective scale Youtube

May 7, 2021: Coupled Data Assimilation

Presenter Title Video
Sergey Frolov Coupled Ocean-Atmosphere Covariances in Global Ensemble Simulations: Impact of an Eddy-Resolving Ocean Youtube
Qi Tang Strongly coupled data assimilation with the coupled ocean-atmosphere model AWI-CM: comparison with the weakly coupled data assimilation Youtube
Zofia Stanley Multivariate localization functions for strongly coupled data assimilation Youtube
Bo Huang Development of Global Ensemble-based Data Assimilation System in JEDI for Aerosol Forecasting and Reanalysis using the GEFS-Aerosols Model Youtube
Alberto Carrassi Data assimilation in coupled chaotic dynamics and its combination to machine learning to infer unresolved scale error Youtube

June 4, 2021: Earth Systems Components and Further Applications of DA

Presenter Title Video
Longjiang Mu The Seamless Sea Ice Prediction System Based on AWI-CM Youtube
Angelica M. Castillo Reconstructing the Dynamics of the Outer Electron Radiation Belt by Means of the Standard and Ensemble Kalman Filter with the VERB-3D Code Youtube
Yohei Sawada Socio-Hydrological Data Assimilation: Analyzing Human-Flood Interactions by Model-Data Integration Youtube
Maximilian Hamm Estimating Thermophysical Properties of Asteroid (162173) Ryugu Using Data Assimilation Youtube
Reyko Schachtschneider Inferring Mantle Viscosity Through Data Assimilation of Relative Sea-Level Observations in a Glacial Isostatic Adjustment Model Youtube

July 2, 2021: Error Covariance Estimation in Observations, State, and Model

Presenter Title Video
Naila F. Raboudi Ensemble Kalman filtering with colored observation noise N/A
Samuel K. Degelia Impacts of Flow-dependent and Static Observation Error Estimation for the Frequent Assimilation of Thermodynamic Profilers on Convective-scale Forecasts Youtube
Hao-Lun Yeh Including observation error correlation for ensemble radar radial wind assimilation and its impact on heavy rainfall prediction Youtube
Jérémy Briant Background error covariance matrix estimation from multifidelity ensembles Youtube
Clara Draper Accounting for land model uncertainty in numerical weather prediction ensemble systems: toward ensemble-based coupled land/atmosphere data assimilation Youtube

Nov. 5, 2021: Chemistry and Aerosols: Modelling, Observations, and DA

Presenter Title Video
Shih-Wei Wei Toward Aerosol-aware Data Assimilation System: Accounting for Aerosol Transmittance Effects on Radiance Observation Operator Youtube
Louie Grasso Satellite Imagery and Products of the 16-17 February 2020 Saharan Air Layer Dust Event over the Eastern Atlantic: Impacts of Water Vapor on Dust Detection and Morphology Youtube
Louie Grasso A fast visible-wavelength 3D radiative transfer model for numerical weather prediction visualization and forward modeling Youtube
Tie Dai Aerosol Data Assimilation using the Four-Dimensional Local Ensemble Transform Kalman Filter Youtube
Xinxin Ye Constraining Vertical Allocation of Wildfire Emissions using Airborne DIALHSRL Observations during FIREX-AQ Youtube

Dec. 3, 2021: Machine Learning for Data Assimilation

Presenter Title Video
Daisuke Hotta VAE as a Stochastic Multidimensional Extension to Gaussian Anamorphosis Youtube
Quentin Malartic State, Global and Local Parameter Estimation using Local Ensemble Kalman Filters: Applications to Online Machine Learning of Chaotic Dynamics N/A
Lucia Minah Yang Machine Learning Techniques to Construct Patched Analog Ensembles for Data Assimilation Youtube
Maria Aufschlager Deep Learning for Retrieving Terrestrial Water Storage (TWS) from Spaceborne Gravity Observations and Satellite Altimetry Youtube
Maximiliano A. Sacco Forecast Uncertainty for Data Assimilation using Neural Network Youtube

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