月別アーカイブ: 2018年7月

平成30年7月豪雨に関する緊急対応研究会 (8月17日) のご案内

先日の豪雨災害について,気象学者による最初の緊急対応として研究会を開催します.

本研究会は専門家間の情報交換・議論を目的としておりますが,ご興味のある方はどなたでも参加いただくことができます(ただし会場の都合により,ご参加のためには事前の登録が必要です).

詳細は下記,特設ページをご覧ください.
研究会ウェブページ

第48回/49回データ同化セミナー(7月27日)のご案内

7月27日のデータ同化セミナーについてのご案内です。

今回のセミナーでは、
Dr. Hironori Arai (Institute of Industrial Science, The University of Tokyo)
Prof. Pierre Tandeo (IMT Atlantique)
の2名の講演者よりご講演頂きます。

※どなたでもご参加いただけますが、入館に手続きが必要なため、
事前に下記までご連絡をお願い致します。
da-seminar(please remove here)@riken.jp

以下URLに随時情報を更新しています。
http://data-assimilation.riken.jp/en/events/da_seminar/

以下、詳細です。

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Date:  July 27, 15:30-16:30
Place:   Room – C107 at R-CCS
Language:  English
Speakers:
15:30-16:00 Dr. Hironori Arai (Institute of Industrial Science, The University of Tokyo)
16:00-16:30 Prof. Pierre Tandeo (IMT Atlantique)

– Dr. Hironori Arai –

Title:
Establishing an integrated MRV system of Greenhouse gas emission from wetlands
with Japanese earth-observation/modelling technologies and a data assimilation technique

Abstract:
Greenhouse gas (GHG) emission observation/reduction technologies are attracting
greater deal of attention from policy makers to achieve Sustainable Development
Goals. In terms of GHG accounting, Monitoring, Reporting and Verification (MRV)
systems have become significantly important for the countries which ratified
Paris Agreement by promising Intended Nationally Determined Contributions (INDC).
Not only evaluation of the amount of GHG emitted from the countries, but also
the mitigation’s effect and its dissemination status need to be monitored by
the policy makers. In this regard, the societies require the MRV systems with
transparency and high cost-performance. To address such concern, the authors
are building an efficient/transparent MRV system in a tropical rice cropping
system based on satellite remote sensing data. We are developing a long-term
consistent bottom-up approaching method with high spatio-temporal resolution,
based on the Japanese earth observation technology (e.g., ALOS-2, AMSR-E/2,
GCOM-C). In order to validate the outputs from the bottom-up approaching method,
Now we are also challenging to build an independent top-down approaching
method based on the other satellites data (GOSAT,SCIAMACHY,AIRS) using
NICAM-LETKF with 1way-multivariate variable localization, which can estimate
the surface fluxes without requiring any direct observation or a-priori information of the fluxes with K-computer. In this presentation, we would like
to discuss the development plan and expected collaboration with further
cross-disciplinary collaboration.

– Prof. Pierre Tandeo –

Title:
Data-driven methods in geophysics

Abstract:
This seminar will be divided in two parts. Firstly, I will present some
recent results about a review paper I am preparing. It deals with the
different methods we find in the data assimilation literature to jointly
estimate Q and R. These error covariance matrices are crucial because
they control the relative weights of the model forecasts and the
observations in filtering methods. I will remind the different methods
and present some numerical comparisons on toy-models.
Secondly, I plan to present various applications of data-driven methods
in geophysics, not especially for data assimilation. I will show some
applications of the analog method and deep learning in environmental
problems, e.g. the nowcasting of solar irradiance using geostationary
satellites and the classification of oceanic and atmospheric phenomena
using SAR images.

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The 47th Data Assimilation Seminar (June 28)

We held the 47th Data Assimilation Seminar at RIKEN Center for Computational Science (R-CCS) on June 28.

The seminar talk was given by Prof. John C. Wells from Ritsumeikan University. He has stayed in our team as a visiting scientist for two months since May. During this stay, he has been working on research aiming for nowcasting of water current and temperature of Lake Biwa.

In this seminar, we learned the water flow measurement in Lake Biwa using the method called Coastal Acoustic Tomography (CAT) and a comprehensive review of the methods to estimate subsurface flow from the fluctuating velocities and height at the surface of a river or sea.

DA seminar, Lecture, 28th Jun. 2018
DA seminar, Group photo, 28th Jun. 2018

For details, please see the following DA seminar page:
http://www.data-assimilation.riken.jp/en/events/da_seminar/archive/20180628_Wells.html