日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 M (領域外・複数領域) » M-TT 計測技術・研究手法

[M-TT46] 統合地球観測システムとしてのGPS/GNSSの新展開

2019年5月27日(月) 13:45 〜 15:15 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:小司 禎教(気象研究所気象衛星・観測システム研究部第2研究室)、市川 香(九州大学応用力学研究所)、太田 雄策(東北大学大学院理学研究科附属地震・噴火予知研究観測センター)、津川 卓也(情報通信研究機構)

[MTT46-P10] Study of the Mechanisms of Severe Thunderstorm in Tokyo Metropolitan Area using High Frequent Assimilation of GNSS and Other Ground-based Observations

*小司 禎教1酒井 哲2足立 アホロ1吉田 智2永井 智広2 (1.気象研究所気象衛星・観測システム研究部第2研究室、2.気象研究所気象衛星・観測システム研究部第3研究室)

キーワード:水蒸気、データ同化、局地豪雨

Highly urbanized Tokyo metropolitan area is vulnerable to severe storms such as local torrential rainfall, thunder lightning and tornado. Recently, the number of days with thunderstorms has been increasing in Tokyo. Elucidation of the mechanism of extreme weather in Tokyo is urgent matter (Nakatani et al. 2013). To study the rolls of water vapor and wind for the rapid life-cycle (initiation, development and dissipation) of hazardous cumulus convection, we installed a mobile Raman-lidar (Sakai et al. 2018), a wind profiler, and five GNSS stations in and around Tokyo.

Using 3DVAR capability of WRF data assimilation system (WRFDA)(Barker et al. 2012) , three-dimensional atmospheric fields with 1 km horizontal resolution were produced at every 10min throughout the August 2017 and 2018. Background fields were produced by JMA nonhydrostatic model (NHM)(Saito et al. 2007). In addition to the observed data at these campaign observation instruments, Japan Meteorological Agency’s operational surface meteorological stations, wind-profiler stations and GNSS PWV derived at dense GNSS network of Geospatial Information Authority of Japan are assimilated. We confirmed that the reproduced atmospheric fields (Temperature, humidity, and wind) showed better agreement with observations of radiosonde, lidar derived water vapor mixing ratio, and wind-profiler than background fields at altitudes lower than 2 km. Assimilation of surface meteorological observations (atmospheric pressure, temperature, humidity and wind) introduced better agreement mainly at altitude lower than 0.5 km. Inclusion of GNSS derived PWV resulted better agreement of humidity at altitude higher than 0.5 km and inclusion of wind field from wind-profiler led better agreement of wind field.

We have investigated roles of water vapor for several local heavy rainfall events occurred in Tokyo in August 2017 and 2018 and found that convergence of water vapor flux at 0.5 km altitude had intensified prior to the occurrence of torrential precipitation. Statistical and quantitative results will be discussed at the symposium.



This study is supported by JSPS KAKENHI Grants 17H00852.