Roland Potthast Webhome

• Nov 28-29, 2024: ICON Board Meeting https://icon-model.org
• Nov 2-9, 2024: Seoul, Korea, KIAPS Workshop and Scientific Advisory Committee (SAC)

• Oct 28-30, 2024: ICON All-hands meeting in Hamburg, Germany, Organizer.
• Oct 21-25, 2024: International Symposium on Data Assmilation (ISDA), Kobe, Japan, Scientific Committee ISDA Kobe, ISDA Online

• Sept 30-Oct 3, 2024: European Working Group on Limited Area Modeling EWG-LAM Meeting in Prague, Talk on E-AI Programme EWGLAM Web

• Sept 26, 2024: Staff Council Assembly (Personalrat) Hamburg, Talk on AI Technology and DWD Activity
• Sept 25-26, 2024: Extreme Weather Congress, Hamburg https://extremwetterkongress.org/
• Sept 23-24, 2024: DWD-DLR Coordination Group Meeting
• Sept 19-20, 2024: ICON Seamless Meeting in Hamburg, Seewetteramt ICON-Seamless Web
• Sept 9-12, 2024: NHR Conference with NHR User Panel Meeting on Sept 11, 2024 in Darmstadt NHR Conference 2024

• Sept 2-6, 2024: COSMO General Meeting (COSMO GM) in Offenbach, Germany. Organizer, Steering Committee COSMO GM 2024

• August 26-30, 2024: Data Assimilation Summer School, University of Hamburg, Lecturer/Co-Organizer (moved to 2026!!)

• August 28-29, 2024: DWD FE Leadership Meeting at the Lindenberg Observatory Youtube Film on Lindenberg
• August 23, 2024: “SWR Leute” - Interview Partner for SWR1 Leute

• July 16-17, 2024: KIT-DWD Hackathon on AI Modeling with the teams of Charlotte Debus Charlotte Web, see also RAI - Junior Research Group Robust and Efficient AI, Julian Quinting Julian Web and Sebastian Lersch Sebastian Web

• July 5, 2024: Southampton, UK: Kick-off Mathematics of the Future Climate MFC CDT, MFC Website, EPSRC Announcement of MFC CDT

• June 15-28, 2024: Activity at Reading, London and Oxford, UK
• June 5-6, 2024: E-AI Workshop on AI/ML for Products and Services in Weather, Climate and Environment E-AI Workhop at KNMI

• May 26-29, 2024: Cineca, Bologna, Italy, GLORI4DE Project Meeting Cineca Project Page, GLORI4DE at ItaliaMeteo

• May 15, 2024: LA24 SIAM Conference Linear Algebra 2024, Paris, Talk on Preconditioning for Data Assimilation, Participation in Minisymposium LA24

• April 25, 2024: ESM-W Workshop, Coupled Atmosphere-Ocean-Waves Earth System Modeling on the Weather Scale
• April 18, 2024: Gauss Computing Centre (GCS) Lenkungsausschuss https://www.gauss-centre.eu
• April 22-23, 2024: ITMS Project Meeting in Karlsruhe

• April 11-12, 2024: DestinE Meeting Bonn, GLORI Digital Twin, E-AI Programme working with DestinE and ECMWF DestinE Web Meeting Site

• March 16-26, 2024: Personal Visit in Libanon

• March 8, 2024: Kick-off of the Strategic Expert Team (SET) of the E-AI EUMETNET Programme on Artificial Intelligence in Weather, Climate and Environment
• EUMETSAT to contribute to EUMETNET E-AI Programme on Artificial Intelligence for Weather, Climate and Environmental Applications: News

• March 8-9, 2024, COSMO Steering Committee Meeting (COSMO STC) https://www.cosmo-model.org Structure COSMO
• March 4-8, 2024, ICCARUS: ICON COSMO ART User Seminar with about 250 participants in Offenbach, Germany Web

• Feb 29, 2024 Koordination Group Numerical Weather Prediction at DWD (KG NWV)
• Feb 27-28, 2024 National ESM Strategy Workshop natESM in Leipzig https://www.nat-esm.de/services/trainings/events/ws_february2024, Steering Group

• Febr 19-20, 2024, EUMETSAT AI Workshop, Darmstadt
• Feb 2, 2024, Integrated Greenhouse Gas Monitoring System (ITMS) Project Meeting in Offenbach https://www.itms-germany.de/

• Jan 30-31, 2024: Earth-System-Model ESM-Meeting DWD-MPI in Hamburg
• Jan 29, 2024, COSMO Steering Committee Meeting (COSMO STC)https://www.cosmo-model.org

• Jan 23-24, 2024: EUMETNET Programme Manager Meeting Brussels (hybrid) https://www.eumetnet.eu
• Jan 10-13, 2024: Cineca Bologna, GLORI4DE Project Meeting, GLORI Digital Twin for Destination Earth

• Jan 1, 2024: Start of the EUMETNET Programme on “Artificial Intelligence and Machine Learning in Weather, Climate and Environment” (E-AI), Programme Management, see e.g. WMO Announcement, Article EUMETSAT Contribution to E-AI

Previous News News RP 2023, News RP 2022, News RP 2021, News RP 2020, News RP 2019, News RP 2018, News RP 2017, News RP 2016.

Our department FE1 for Numerical Weather Prediction (NWP) of the German Weather Service (DWD) consists of about 110-120 scientists at DWD headquarters in Offenbach close to Frankfurt/Main and in Potsdam close to Berlin, about 60 of them on funded R&D projects. The department consists of four sections, with 20-35 scientists each:

• Data Assimilation and Predictability (FE11),
• Observations Modeling and Verification (FE12),
• Numerical Modeling (FE13),
• Physical Processes and Dispersion (FE14).

DWD is a part of the German Ministery of Transport and Digital Infrastructure (BMVI), but our work is carried out in intensive cooperation with

• the Max-Planck-Institute for Meteorology MPI-M, see also ICON,
• the German Climate Computing Center DKRZ,
• the Karlsruhe Institute of Technology KIT, in particular with ICON-ART,
• ETH Zurich, in particular C2SM,
• the weather services of the COSMO Consortium (Italy, Switzerland, Russia, Poland, Romania, Greece and Israel),
• the Meteorological Service of the German Armee Geo BW, see also PDF,
• the Hans-Ertel Center HErZ research branches at the Universities of Munich, Bonn, Frankfurt, Hamburg, Berlin

and further international partners such as the

• European Centre for Medium Range Weather Forecasting ECMWF located in Reading, Bologna and Bonn.
• EUMETSAT, in particular the NWP-SAF Consortium with the Partners MetOffice (UK), Meteo-France, ECMWF and DWD.

We are working on modeling and data assimilation for numerical weather prediction (NWP) and earth system simulation (ESM). Our main task is to provide operational data assimilation and forecasting with

• ICON-global, i.e. a global NWP-model with 13km resolution, 120 layers 75km height, run every 3 hours 24/7,
• ICON-EU, i.e. its mesoscale two-way-nesting area over Europe with 6.5km resolution and the
• ICON-D2, i.e. high-resolution convection-permitting analysis and forecasts over central Europe with 2km resolution, 24km height analysis every hour 24/7, forecasts every three hours.

We prepare a rapid update cycle (RUC) with forecasts every hour in integration with Nowcasting techniques. This system is called

• ICON-RUC and SINFONY, see also SINFONY Webpage.

Our development and services include ensemble data assimilation for the ensemble prediction systems

• ICON-EPS global with 26 km resolution and 40 members and
• ICON-EU-EPS with 13km resolution over Europe with 40 members as well as
• ICON-D2-EPS with 2km resolution over central Europe, 40 members.
• ICON-D1 and ICON-D05 with 1km resolution and 500m resolution is under development.

We run a

• hybrid ensemble-variational data assimilation scheme (EnVar) globally, i.e. a variational data assimilation scheme, coupled with an Localized Ensemble Transform Kalman Filter (LETKF).
• For ICON-D2 we employ the four-dimensional version of the Localized Ensemble Transform Kalman Filter (4D-LETKF).

Further,

• Particle filters, in particular the Localized Adaptive Particle Filter LAPF and Localized Mixture Coefficients Particle Filter LMCPF are available for global and regional scale and are being used for research within the operational framework.
• EnVar for convective-scale ICON-D2 is under development,
• 4D-EnVAR for both global and regional systems
• an ultra-rapid data assimilation scheme (URDA) based on our ensemble and also
• a coarse EnVar (cEnVar) using our global ensemble for regional ensemble data assimilation world-wide are being developed and tested.

Data Assimilation includes the use of a broad varity of both direct and remote sensing measurements from

• Ground Stations and Ships (SYNOP),
• Radio Sondes (TEMP) and dropsondes,
• Buoys,
• Air Planes (AMDAR, AIREP, ACAR, …),
• Atmospheric Motion Vectors (AMV),
• Scatterometers (SCAT),
• Infrared Sounders (IR),
• Microwave Sounders (MW) and Microwave Radiometers (MWR),
• LIDAR including Clound Bottom Height (CBH), Cloud Top Height (CTH), Backscatter Profiles, Line-of-Sight Winds (AEOLUS), Ceilometers,
• RADAR including RADAR Radial Winds, RADAR Reflectivity and RADAR Dual Polarization,
• GPS/GNSS including Radio Occultations (RO), Zenith Total Delay (ZTD), Slant Total Delay (STD),
• Cameras,
• Cars.

Geostationary satellites and polar orbiting satellites are used operationally, while a lot of research is going into the better use of hyperspectral observations (many thousand frequencies per observed atmospheric column) in particular over land and in cloudy situations. The observation and reconstruction of snow, ice, sea surface temperature, land surface temperature, coverage, emissivity and soil moisture is a very active area of research. Also, the observation and data assimilation of clouds and convective processes with high-impact phenomena such as thunderstorms, heavy rain and wind gusts with lead times from minutes to days is a special focus of our research.

The research of our group at the University of Reading, UK, is concerned with inverse problems and data assimilation in three areas:

• numerical weather prediction (NWP),
• cognitive neuroscience / neural field theory (NFT),
• inverse scattering problems / remote sensing.

These are extremely exciting areas scientifically and very important for society, for example for air traffic control, severe weather warnings and national energy supply, in medicine by medical imaging and for many industrial and environmental questions.

Since October 2020 I am heading the department on Numerical Weather Prediction (NWP) of DWD with about 110-120 researchers in-house (state June 2024). There are four division heads in this department to lead sections of approximately 20-35 researchers each, see group.

Thinking about faith and life has always been a passion for me. I have become a Christian and have started to explore the world as someone who follows Jesus - that has turned out to be quite an adventure and highly exciting. In my daily blog I explore thoughts and arguments about faith, and monitor how faith works on a daily basis: Jesus Network

Recent publications can be found on publications. A book Inverse Modeling by Nakamura and Potthast with an introduction into data assimilation and inverse problems has recently appeared at IOP.

Working in an operational center, our focus is to develop state-of-the-art high-dimensional analysis and simulation methods which can be run in a reliable way on a supercomputer in near real-time. It includes codes simulating atmospheric processes, fluid-dynamics, physical parametrizations, scattering of waves, propagation of light and radiation, tomography, large-scale optimization and uncertainty quanitfication, ensemble and particle methods.

With a SX-Aurora TSUBASA C401-8 of NEC our supercomputers at Deutscher Wetterdienst are no 101 and no 136 (June 2024) List on the TOP-500 Supercomputer List. We have access to Cray XC40, Xeon E5-2695v4 of ECMWF, Mistral - bullx DLC 720, Xeon E5-2680v3 12C of DKRZ and Piz Daint - Cray XC50, Xeon E5-2690v3 12C 2.6GHz, Aries interconnect, NVIDIA Tesla P100 of CSCS in Switzerland.

High-performance computing is our daily business, however, the development of insight into the scientific problems we need to solve is an indispensable ingredient of our daily work. Part of this insight is based on mathematical analysis and the testing of computational methods for purpuse-built small-scale demonstration systems.

• Frontiers in Applied Mathematics and Statistics - Dynamical Systems
• Mathematical Inverse Problems

• Steering Committee (STC) COSMO Consortium COSMO Structure
• Steering Committee ICON Consortium https://icon-model.org
• Steering Committee German national Earth System Modeling natESM Steering

• Programme Manager EUMETNET Programme Artificial Intelligence for Weather, Climate and Environmental Applications WMO Announcement

• Steering Committee High-Performance Computing Center Stuttgart https://www.hlrs.de/, HLRS
• National High-performance Computing (NHR) KIT representative Earth System Science https://www.scc.kit.edu/dienste/nhr.php
• National High-performance Computing (NHR) User Committee NHR User Committee
• Gauss Centre for Supercomputing Steering Committee https://www.gauss-centre.eu/, Gauss Steering Committee