Data Assimilation Seminar Series

Next Seminar

Date & Time 16:00 - 17:30 Tuesday 19th March 2024
Place & Contact C107 (Room) or Zoom (Online)
Language English
Speaker

Prof. John Wells (Ritsumeikan University, Japan / RIKEN, R-CCS)

Title

Tools to evaluate 3D hydrodynamic simulations of stratified lakes, and to assimilate limited temperature observations

Abstract

Stresses on global freshwater resources will grow acutely with climate change and population growth, and development of ICT tools to better manage water resources will correspondingly increase in importance. To inform scientific understanding, better manage the ecosystem, and possibly to track disastrous pollutant release, this work aims to develop a system to nowcast 3D hydrodynamics in Lake Kinneret (Israel) and Lake Biwa (Japan).
In the first part I consider how Principal Component Analysis (PCA) might help validate results from numerical simulations of a stratified lake, and compactly summarize the comparison by extending the well-known Taylor Diagram. Excepting our earlier contribution (Wells et al, SIL Congress 2022), PCA has not been applied to validate simulations in limnology. We compare the first few PCA spatial modes of temperature profiles in the simulation versus observation, together with the variance in each mode. To validate the time-varying weights requires a common basis, taken herein as the spatial modes from the observations. For analysis of temperatures, especially for the short unsteady record measured in spring in Lake Biwa, we also consider whether temperature "fluctuations" at each depth should be defined with respect to the sample mean at that depth, or alternatively to a background "deep, cold" reference temperature.
Prior efforts to assimilate observations into 3D lake simulations have been suprisingly limited. In a second part, I will discuss ungoing efforts to assimilate temperature observations at various depths of a single mooring near the center of Lake Biwa. My current implementation simply nudges water temperatures every hour, equally in horizontal planes, in proportion to the difference between the 24-hour boxfiltered temperature observation, and its corresponding simulated value. This suffices to suppress the numerical diffusion of heat that plagues most 3D hydrodynamic simulations, and therefore maintain a fairly realistic profile of buoyancy frequency.

Archives

Number Date Speaker Title (click the title to see abstract )

2024-01

(97th)

January 23,
2024
Prof. Shunji Kotsuki (Chiba University, Japan / RIKEN, R-CCS) Quantum Data Assimilation: A New Approach to Solve Data Assimilation on Quantum Annealers

2023-05

(96th)

November 20,
2023
Dr. Shigenori Otsuka (Research Scientist, RIKEN, R-CCS) Precipitation nowcasting with deep learning

2023-04

(95th)

October 6,
2023
Dr. Meghan Cronin (Oceanographer, NOAA /PMEL & Guest Professor, The University of Tokyo) Observing Air-Sea Interactions in Frontal Regions from the Tropics to Western Boundary Current Extensions

2023-03

(94th)

July 3,
2023
Dr. Tobias Necker, (University of Vienna, Austria / RIKEN,R-CCS) The Potential of Large Ensemble Simulations: Insights from 5 Years of Research with a 1000-Member Ensemble.

2023-02

(93rd)

June 26,
2023
Dr. Prashant Kumar, (Indian Space Research Organisation, India) The Assimilation Impact of Indian Satellites to Improve Short Range Weather Prediction using WRF Model

2023-01

(92nd)

January 20,
2023
Prof. Takahiro Hosono (Kumamoto University, Japan) Making contamination future scenario: toward sustainable management of groundwater and surface water resources

2022-08

(91st)

November 14,
2022
Dr. Atsushi Okazaki (Hirosaki University, Japan) Observation error estimation in climate proxies with data assimilation and innovation statistics

2022-07

(90th)

October 21,
2022
Prof. Ronan Fablet (IMT Atlantique, France) 4DVarNets to learn Variational Data Assimilation and Solvers: application to space oceanography

2022-06

(89th)

September 14,
2022
Prof. Shunji Kotsuki (Chiba University, Japan) Combining Data Assimilation and Sparse Sensing Placement Method For Designing Better Observing Networks

2022-05

(88th)

May 11,
2022
Ms. Audrey Gonzalo (RIKEN) Towards acceleration of a high-resolution weather model with machine learning: a summary of short-IPA internship

2022-04

(87th)

April 6,
2022
Prof. Craig H. Bishop (University of Melbourne, Australia) The Bounded Variable Ensemble Transform Filter: A non-linear, non-Gaussian extension of the LETKF

2022-03

(86th)

February 18,
2022
Prof. Bo-Wen Shen (San Diego State University, USA) Coexisting Chaotic and Non-chaotic Attractors, Multistability, Multiscale Instability, and Predictability within Lorenz Models

2022-02

(85th)

January 20,
2022
Prof. Avelino F. Arellano (University of Arizona, USA) The Impact of Precipitable Water Vapor Data Assimilation on North American Monsoon Precipitation Forecast in Northern Mexico

2022-01

(84th)

January 7,
2022
Prof. Keiya Yumimoto (Kyushu Univesrsity) Integration of aerosol satellite retrieval and data assimilation

2021-11

(83rd)

Novermber 29,
2021
Prof. Naoki Hirose (Kyushu Univesrsity) Moderately-determined data assimilation with coastal ocean models

2021-10

(82nd)

Novermber 5,
2021
Dr. Philippe Baron (NICT) Study of 3D recurrent neural networks for very short-term prediction of torrential rains with a Multi-Parameter Phased-Array Radar (MP-PAWR)

2021-09

(81st)

September 30,
2021
Dr. Shunsuke Noguchi (JAMSTEC) Gravity wave resolving prediction experiments by using a Japanese Atmospheric GCM for Upper Atmosphere Research (JAGUAR) and its data assimilation product

2021-08

(80th)

July 16,
2021
Dr. Milija Zupanski
(Cooperative Institute for Research in the Atmosphere)
An ensemble data assimilation method with state-space covariance localization and global numerical optimization

2021-07

(79th)

June 23,
2021
Dr. Akira Yamazaki
(JAMSTEC)
EFSO at different geographical locations verified with observing-system experiments

2021-06

(78th)

April 14,
2021
Dr. Pierre Tandeo
(IMT Atlantique)
Narrowing uncertainties in climate projections using data science tools

2021-05

(77th)

April 9,
2021
Mr. Thomas Hitchcock
(University of St Andrews)
Conflicts and trade-offs in relation to sex

2021-04

(76th)

March 31,
2021
Dr. Yicun Zhen
(Ifremer & IMT Atlantique) &
Dr. Arata Amemiya
(R-CCS)
Location uncertainty from another point of view/ Connecting Data Assimilation and Neural ODE

2021-03

(75th)

March 18,
2021
Dr. Maha Mdini
(R-CCS) &
Dr. Simon Benaichouche
(IMT Atlantique & e-odyn)
Accelerating Climate Model Computation by Neural Networks/ Variational learning of sea surface current reconstructions from AIS data streams

2021-02

(74th)

March 3,
2021
Mr. Aurelien Colin
(IMT Atlantique & CLS, France) &
Dr. Hirotaka Hachiya
(Wakayama University, Japan)
Semantic Segmentation of Metocean Processes and Estimation of Ancillary Data/ Spatio-temporal integration of forecast guidance outputs using U-Net

2021-01

(73rd)

February 17,
2021
Dr. Takemasa Miyoshi
(R-CCS, Japan)
Big Data, Big Computation, and Machine Learning in Numerical Weather Prediction.

2020-12

(72nd)

December 8,
2020
Dr. Maha Mdini
(R-CCS, Japan)
Accelerating Climate Model Computation by Neural Networks: A comparative study.

2020-06

(71st)

November 20,
2020
Dr. Koji Terasaki
(R-CCS, Japan)
Including the horizontal observation error correlation in the assimilation of AMSU-A data.

2020-05

(70th)

October 1,
2020
Prof. Shu-Chih Yang
(NCU, Taiwan)
Recent improvements of the NCU convective-scale ensemble data assimilation system and their impact on short-term precipitation prediction in Taiwan.

2020-04

(69th)

September 11,
2020
Prof. Shunji Kotsuki and Dr. Keiichi Kondo
(Chiba University and JMA-MRI)
A local particle filter based on non-Gaussian statistics using an intermediate AGCM (Dr. Kondo). A Local Particle Filter and Its Gaussian Mixture Extension: Experiments with an Intermediate AGCM (Prof. Kotsuki)

2020-03

(68th)

July 20,
2020
Prof. Yohei Sawada
(University of Tokyo)
Advancing hydrometerological prediction by the integration of process-based simulation and machine learning

2020-02

(67th)

June 10,
2020
Dr. Guo-Yuan Lien
(CWB, Taiwan)
Recent data assimilation work at Taiwan's Central Weather Bureau (CWB) and perspectives on its global NWP development

2020-01

(66th)

May 1,
2020
Dr. James Taylor
(R-CCS)
Oversampling Reflectivity Observations from a Geostationary Precipitation Radar Satellite: Impact on Typhoon Forecasts within an OSSE Framework

2019-13

(65th)

Dec 2,
2019
Dr. Shun Ohishi
(Nagoya University)
An LETKF-based ocean data assimilation system for the Asia-Oceania region

2019-12

(64th)

Oct 25,
2019
Dr. Naoto Nakano
(Kyoto University)
Data driven modeling using reservoir dynamics

2019-11

(63rd)

Sep 30,
2019
Prof. Michael Ng
(Hong Kong University)
Robust Tensor Completion and Its Applications

2019-10

(62nd)

Sep 10,
2019
Prof. Shu-Chih Yang
(National Central University, Taiwan)
Recent developments and challenges of the regional ensemble data assimilation system for high-impact weather prediction in Taiwan

2019-9

(61st)

Aug 21,
2019
Dr. Shigenori Otsuka
(RIKEN R-CCS)
RIKEN Nowcast: optical flow and machine learning

2019-8

(60th)

July 3,
2019
Dr. Tse-Chun Chen
(University of Maryland)
How to improve forecasts by identifying and deleting detrimental observations

2019-7

(59th)

May 31,
2019
Professor Serge Guillas
(U College London)
Statistical emulation to quantify uncertainties in tsunami modelling using high performance computing

2019-6

(58th)

May 7,

2019

Prof. Ming-Cheng Shiue
(NCTU)
Mathematical analysis of data assimilation algorithms based on synchronization of truth and models

2019-5

(57th)

Apr 25,

2019

Dr. Atsushi Okazaki
(RIKEN R-CCS)
Impact of geostationary satellite borne precipitation radar on numerical weather prediction: An observing system simulation experiment with an ensemble Kalman filter for a typhoon case

2019-4

(56th)

Feb 1,

2019

Dr. Tie Dai
(LASG, IAP,CAS)
Development and application of aerosol data assimilation in NICAM

2019-3

(55th)

Jan 28,

2019

Ms. Jemima Tabeart
(U of Reading)

Using reconditioning to study the impact of correlated observation errors in the Met Office 1D-Var system

2019-2

(54th)

Jan 28,

2019

Dr. Alison Fowler
(U of Reading)

Data compression in the presence of observation error correlations

2019-1

(53rd)

Jan 18,

2019

Prof. Eugenia Kalnay
(U of Maryland)

Can large-scale solar and wind farms create a significant climate change? A model experiment in the Sahara

2018-12

(52nd)

Dec 19,

2018

Dr. Tetsuo Nakazawa
(JMA MRI)

Is the Trend in Tropical Cyclone Formation Frequency due to Global Warming?

2018-10

(51st)

Nov 13,

2018

Prof. Roland Potthast
(DWD/U of Reading)

New Observations and Algorithmic Developments for Convective Scale Ensemble Data Assimilation

2018-09

(50th)

Oct 25,

2018

Dr. Jing-Shan Hong
(CWB, Taiwan)

Re-Center algorithm on the Continuous Cycling Radar Data Assimilation: Multi-scale Blending Scheme

2018-08

(49th)

Jul 27,

2018

Prof. Pierre Tandeo

(IMT Atlantique)

Data-driven methods in geophysics
2018-07 (48th)

Jul 27,

2018

Dr. Hironori Arai

(U Tokyo)

Establishing an integrated MRV system of Greenhouse gas emission from wetlands with Japanese earth-observation/modelling technologies and a data assimilation technique
2018-06 (47th) Jun 28, 2018 Prof. John C. Wells
(Ritsumeikan U)
Towards nowcasting in Lake Biwa: field tests of acoustic tomography, and discussion of some theorems relating the flow at a water surface to that below
2018-05 (46th) Apr 17, 2018 Dr. Kohei Takatama
(R-CCS)
Regional atmospheric data assimilation coupled with an ocean mixed layer model: a case of typhoon Soudelor (2015)
2018-04 (45th) Feb 16, 2018 Prof. Pierre Tandeo
(IMT Atlantique)
The analog data assimilation: method, applications and implementation
2018-03 (44th) Feb 9, 2018 Prof. Roland Potthast
(DWD/U of Reading)
Data Assimilation From Minutes to Days
2018-02 (43rd) Jan 29, 2018 Dr. Shinsuke Satoh
(NICT)
Three-dimensional precipitation data measured by phased array weather radar every 30 seconds
2018-01 (42nd) Jan 18, 2018 Prof. David J. Stensrud
(Penn State U)
(Canceled)
2017-16 (41st) Dec 11, 2017 Dr. Tsuyoshi Thomas Sekiyama
(Meteorological Research Institute, Japan Meteorological Agency)
Data assimilation of atmospheric chemistry: past, present, and future
2017-15 (40th) Nov 17, 2017 Prof. Yusuke Uchiyama
(Kobe U)
Challenges and issues in forward regional ocean modeling: Eddies, terrestrial influences, and surface gravity waves
2017-14 (39th) Oct 12, 2017 Mr. Krishnamoorthy Chandramouli
(IIT Madras)
Dr. Koji Terasaki
(R-CCS)
Impact of assimilating humidity sounder radiances with the NICAM-LETKF system
2017-13 (38th) Sep 26, 2017 Mr. Cheng Da
(U of Maryland)
Dr. Guo-Yuan Lien
(RIKEN AICS)
Assimilation of the GSMaP Precipitation Data with the SCALE-LETKF System
2017-12 (37th) Aug 16, 2017 Ms. Paula Maldonado
(CONICET-U of Buenos Aires)
Radar Data Assimilation in a Case of Deep Convection in Argentina
2017-11 (36th) Aug 16, 2017 Mr. Sam Hatfield
(Oxford U)
How low can you go? Reducing the precision of data assimilation to improve forecast skill
2017-10 (35th) Aug 4, 2017 Dr. Chih-Chien Tsai
(TTFRI, Taiwan)
Preliminary Experimental Results of Polarimetric Radar Data Assimilation in the Case of Typhoon Soudelor (2015)
2017-09 (34th) Jun 26, 2017 Dr. Toshio Iguchi
(NICT)
Radar Measurement of Precipitation from Space: TRMM/PR and GPM/DPR rain retrieval algorithms data
2017-08 (33rd) May 18, 2017 Dr. Guo-Yuan Lien
(RIKEN AICS)
30-second-cycle convection-resolving data assimilation of dense phased array weather radar data
2017-07 (32nd) Mar 7, 2017 Dr. Alison Fowler
(U of Reading)
On the interaction of observation and a-priori error correlations in data assimilation
2017-06 (31st) Mar 7, 2017 Dr. Joanne A. Waller
(U of Reading)
Diagnosing observation error statistics for numerical weather prediction
2017-05 (30th) Mar 7, 2017 Prof. Nancy K. Nichols
(U of Reading)
New applications and challenges in data assimilation
2017-04 (29th) Mar 6, 2017 Prof. Steven J. Greybush
(Penn State U)
Ensembles, Data Assimilation, and Predictability for Winter Storms
2017-03 (28th) Mar 6, 2017 Prof. Eugenia Kalnay
(U of Maryland)
Modeling Sustainability: Coupling Earth and Human System Models
2017-02 (27th) Feb 7, 2017 Prof. Hiromichi Nagao
(U of Tokyo)
Promises and Challenges in Assimilation of Infrared and Microwave All-sky Satellite Radiances for Convection-Permitting Analysis and Prediction
2017-01 (26th) Jan 13, 2017 Prof. Fuqing Zhang
(Penn State U)
Data assimilation for massive autonomous systems based on a second-order adjoint method
2016-09 (25th) Dec 22, 2016 Dr. Takahiro Nishimichi
(Kavli IPMU, U of Tokyo)
Dark Emulator: cosmic large-scale structures and parameter estimate
2016-08 (24th) Dec 21, 2016 Dr. Takumi Honda
(RIKEN AICS)
Assimilating All-Sky Himawari-8 Satellite Infrared Radiances: Preliminary Case Studies
2016-07 (23rd) Nov 24, 2016 Mr. Yasumitsu Maejima
(RIKEN AICS)
Impacts of dense and frequent surface observations on a sudden severe rainstorm forecast: A case of an isolated convective system
2016-06 (22nd) June 13, 2016 Mr. Yasutaka Ikuta
(JMA)
Assimilation of GPM/DPR at JMA
2016-05 (21st) Apr 14, 2016 Dr. Yohei Sawada
(RIKEN AICS)
Advancing land data assimilation science to monitor terrestrial water and vegetation dynamics
2016-04 (20th) Mar 16, 2016 Dr. Juan Ruiz
(U Buenos Aires (CIMA)/RIKEN AICS)
Implementation and evaluation of a regional data assimilation system based on WRF-LETKF
2016-03 (19th) Mar 7, 2016 Prof. Roland Potthast
(DWD/U of Reading)
On Ensemble and Particle Filters for Large-Scale Data Assimilation
2016-02 (18th) Mar 2, 2016 Ms. Chang Yaping
(CAS)
Dr. Shunji Kotsuki
(RIKEN AICS)
Ensemble data assimilation of MODIS surface temperature into land surface model
2016-01 (17th) Feb 17, 2016 Mr. Sho Yokota
(JMA MRI)
Comparison between LETKF and EnVAR with observation localization
2015-10 (16th) Dec 25, 2015 Dr. Shunji Kotsuki
(RIKEN AICS)
Ensemble Data Assimilation of GSMaP precipitation into the nonhydrostatic global atmospheric model NICAM
2015-09 (15th) Dec 15, 2015 Dr. Kozo Okamoto
(MRI-JMA/RIKEN AICS)
Assimilation of cloud-affected infrared radiances
2015-08 (14th) Oct 21, 2015 Prof. Kosuke Ito
(U of the Ryukyus)
Advanced data assimilation techniques for predicting tropical cyclone intensities
2015-07 (13th) Sep 16, 2015 Mr. Shumpei Terauchi
(U of Tsukuba)
Dr. Guo-Yuan Lien
(RIKEN AICS)
Verification of the near-real-time weather forecasts and study on 2015 typhoon Nangka with the SCALE-LETKF system
2015-06 (12th) Sep 2, 2015 Dr. Daisuke Hotta
(JMA)
Diagnostic methods for ensemble data assimilation
2015-05 (11th) Jun 25, 2015 Dr. Koji Terasaki
(RIKEN AICS)
Applying the Local Transform Ensemble Kalman Filter to the non-hydrostatic atmospheric model NICAM
2015-04 (10th) Jun 5, 2015 Prof. S. Lakshmivarahan
(U of Oklahoma)
Nonlinear dynamics and Predicitability
2015-03 (9th) Apr 17, 2015 Prof. Takeshi Enomoto
(Kyoto U/JAMSTEC)
Assimilation and forecast experiments using bright band heights
2015-02 (8th) Mar 24, 2015 Dr. Shigenori Otsuka
(RIKEN AICS)
Towards 100-m resolution prediction of local convective storms: predictability and nowcasting
2015-01 (7th) Jan 20, 2015 Dr. Nobumasa Komori
(JAMSTEC)
Development of an ensemble-based data assimilation system with a coupled atmosphere-ocean GCM
2014-06 (6th) Dec 26, 2014 Dr. Keiichi Kondo
(RIKEN AICS)
The 10,240-member ensemble Kalman filtering with an intermediate AGCM without localization
2014-05 (5th) Nov 26, 2014 Prof. Shin-ichiro Shima
(U of Hyogo/RIKEN AICS)
Data assimilation experiments of the dynamic global vegetation model SEIB-DGVM with simulated GPP observations
2014-04 (4th) Nov 26, 2014 Prof. Takeshi Ise
(Kyoto U)
Simulating terrestrial ecosystems: current progress and future perspectives
2014-03 (3rd) Oct 31, 2014 Prof. Masayuki Yokozawa
(Shizuoka U)
Evaluating the productivities of major crops at the global scale using process-based crop model
2014-02 (2nd) Sep 10, 2014 Dr. Guo-Yuan Lien
(RIKEN AICS)
Ensemble Assimilation of Global Large-scale Precipitation
2014-01 (1st) July 23, 2014 Dr. Juan Ruiz
(U of Buenos Aires (CIMA)/RIKEN AICS)
Efficient parameter estimation for numerical weather prediction models using data assimilation

Page Top