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Data Assimilation Seminar – Professor Shu-Chih Yang

We held the 70th Data Assimilation Seminar online at RIKEN Center for Computational Science (R-CCS) on 1 October.

The talk was given by Professor Shu-Chih Yang from National Central University in Taiwan. She discussed her recent work with the NCU convective-scale ensemble data assimilation system and radar data assimilation research. Her updates included improvements in small-scale corrections, such as enhancement of convergence for convective development. Professor Yang also updated us on the work with ground based GNSS ZTD data with rapid update cycling.

We would like to thank Professor Yang once again for taking the time to present her recent updates with us and look forward to discussing about her research in future (hopefully in person!).

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

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Data Assimilation Seminar – Dr Guo-Yuan Lien

On 10 June we held the 67th DA seminar. The speaker was Dr Guo Yuan Lien from Central Weather Bureau in Taiwan.

Dr Lien spoke about the recent work with the operational global numerical weather prediction system used by the CWB including the assimilation of Global Navigation Satellite System radio occultation observations from the COSMIC-2 satellite as well as work with the EFSO on hybrid EnVar DA system.

Dr Lien is a former member of the DA team at RIKEN as it is always great to hear about his research and how his life back in native Taiwan is going. We look forward to hearing again from him in the near future.

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Data Assimilation Seminar – Prof Shunji Kotsuki and Dr Keiichi Kondo

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

On September 11 2020 we held the 69th DA seminar online. The seminar was a joint presentation given by Prof. Shunji Kotsuki from Chiba University and Dr. Keiichi Kondo from JMA-MRI.

They spoke about their work using particle filters in use of high dimensional dynamical systems. Kotsuki-san talked about his development of a local particle filter with use with the LETKF data assimilation scheme and implementation of the Gaussian mixture to improve the local particle filter. His results showed that the added implementation of the Gaussian mixture outperforms the standard local particle filter for sparsely observed regions.

We would like to thank both Prof. Kotsuki and Dr Kondo for talking about their recent work and look forward to discussing more with them in future.

Data Assimilation Seminar – Dr Naoto Nakano

We held the 64th Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 25 October.

The talk was given by Dr Naoto Nakano who is a senior lecturer in the Department of Mathematics at Kyoto University. Today he spoke about his work in data driven modelling based on reservoir dynamics. This included work using the 1963 and 1996 lorenz model to try to better predict the state of variables using pre-exisiting timeseries.

We would like to thank Dr Nakano very much for visiting us again in Kobe and look forward to his next visit!

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

Data Assimilation Seminar – Professor Michael Ng

We held the 63rd Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 30 September.

The talk was given by Professor Michael Ng from Hong Kong University who spoke about his work on robust tensor completion using single value decompression . He demonstrated how these methods can be applied to solve many different problems, including image processing. We would like to thank Professor Ng for given his talk and meeting with the team during his stay. We hope that he will visit us again very soon and update us with his research progress.

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

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Data Assimilation Seminar – Dr. Shigenori Otsuka [R-CCS]

We held the 61st Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 21 August.

The talk was given by Dr. Shigenori Otsuka from the Data Assimilation team here at RIKEN. He presented his research using two optical-flow based nowcasting systems for improving short-range precipitation prediction, 1) Phased Array Weather Radar (PAWR) 3D nowcasting system and 2) Global Satellite Mapping of Precipitation (GSMaP) RIKEN Nowcast (RNC) system. Given the limitations of using optical-flow systems for weather prediction, one being that convective weather systems can evolve very rapidly and non-linearly, his research has steered towards the use of deep learning techniques, where he has applied the Convolutional Long Short-Term Memory (Conv-LSTM) algorithm to the PAWR data. Preliminary results of real-time experiments with Conv-LSTM showed improvements in short-range forecasts.

We would like to thank Dr Otsuka for his interesting talk and wish him well with his continuing research using nowcasting systems.

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

Data Assimilation Seminar – Professor Serge Guillas [UCL]

We held the 59th Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 31 May.

The talk was given by Professor Serge Guillas who was visiting us from University College London (UCL). Professor Guillas spoke about current solutions to investigating uncertainties in tsunami impacts, including investigating the potential for landslides as a source of tsunamis in the Western Indian Ocean and the risk of tsunamis from the Makran subduction zone. Part of his research was using very high resolution models to simulate potential tsunamis in these regions and predict seabed deformations and landslide velocities. We wish Professor Guillas well in the future with his research on this very important topic and hope that he will return again soon to R-CCS to update us on his progress. Thank you!

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

Data Assimilation Seminar – Prof. Ming-Cheng Shiue [NCTU]

We held the 58th Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 7 May.

The seminar was given by Professor Ming-Cheng Shiue from the National Chiao Tung University, Taiwan. He spoke about his research on hybrid, nonlinear continuous data assimilation algorithms for Lorenz systems. He presented his work showing that approximate solutions converge to reference solutions over time provided that only first and second variables of Lorenz systems are synchronized. He also presented research on two continuous and discrete DA algorithms for 2D Navier-Stokes equations, showing how present and past observations at each time step provide a way that new methods could outperform old ones.

We are very grateful to Professor Shiue for visiting us at RIKEN and hope to see him again soon.

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html

Data Assimilation Seminar – Dr Atsushi Okazaki [R-CCS]

We held the 57th Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on 25 April.

The talk was given by our very own Dr. Atsushi Okazaki from the Data Assimilation team at RIKEN R-CCS. Dr Okazaki presented his research on testing the feasibility of a a new type of geostationary satellite that would be able to provide continuous space borne precipitation radar observations, similar to those of Tropical Rainfall Measuring Mission (TRMM) and Global Precipitation Measurement (GPM). Dr. Okazaki has been testing the impact of such observation on numerical weather prediction for a tropical cyclone case. His results showed promising impact on track and intensity forecasts with the assimilation of such observations.

Dr Okazaki has been member of the Data Assimilation team for 3 years but will leave next month to start a new position in the United States . We are very sad to see him leave but wish him all the best in the future and hopefully see him again very soon. Good luck Atsushi!

For more information about this and all our DA seminars at RIKEN R-CCS, please see the DA seminar page:

http://www.data-assimilation.riken.jp/en/events/da_seminar/index.html