岡山大学 地球科学研究報告
Published by Okayama University Earth Science Reports Editorial Committee

東日本の大雨日の降水特性や総観場の解析(盛夏期の気候学的特徴と梅雨最盛期に関する補遺)

Matusmoto, Kengo
Otani, Kazuo
Abstract
 Rainfall characteristics and large-scale atmospheric fields on the “heavy rainfall days” (with more than 50mm/day) in midsummer, and so on, at Tokyo in the eastern Japan were examined for 1971 to 2010, succeeding to Matsumoto et al. (2013)  The present study firstly examined the rainfall features and the atmospheric fields for the “heavy rainfall days” at Tokyo with rather lower appearance frequency than in the typhoon related patterns in Matsumoto et al. (2013) and so on. In these cases (three cases in total), although the synoptic situations were rather different among each other, they seem to occur under the systems with relatively small zonal scale associated with the great meander of the upper-level westerly wind.  Next, the climatological analyses similar to Matsumoto et al. (2013) were performed for the "heavy rain days" at Tokyo in midsummer (1~31 August). The precipitation on the “heavy rainfall days” at Tokyo in midsummer was mainly brought by the intense rainfall with more than 10 mm/h, as in the western Japan in the mature stage of the Baiu season. The detailed examination of the rainfall features for the case on 10 August 2009, with use of the 10-minutes precipitation data and the Radar AMeDAS Composite Data by the JMA, revealed that the organized meso-β-scale convective rainfall systems as often appear in the western Japan in the mature stage of the Baiu season were just to the east of the typhoon, and brought the intense rainfall at Tokyo to result in the large daily precipitation.
Keywords
rainfall characteristics in eastern Japan
heavy rainfall in eastern Japan in the Baiu and midsummer seasons
rainfall climatology
ISSN
1340-7414
NCID
AN10506284
NAID