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

2004年10月後半の台風23号に伴う日本列島での広域の降水(台風18号と比較して)

佐竹 愛
加藤  内藏進 岡山大学大学院教育学研究科
盛 宣誠
合田 泰弘
池田 祥一郎 岡山大学大学院自然科学研究科
塚本 修 岡山大学大学院自然科学研究科
抄録
Rainfall distribution in the Japan Islands associated with the approach of Typhoon No.23 around 20 October 2004 (referred to Ty0423, hereafter) showed considerably different features from those in late summer of this year. The present study examined the detailed rainfall features around the Japan Islands brought by Ty0423 and the atmospheric processes based on the operational observation data by the Japan Meteorological Agency (JMA), comparing with those in association with Ty0418 around 7 September 2004. During the stage when Ty0423 was approaching or landing on the western part of the Japan Islands, the areal mean precipitation from Kyushu to Kanto District attained much larger than that for Ty0418, with wider extension of the area with the large amount of precipitation. It is interesting that, although the intense rainfall was observed only at the upstream side of the mountain range from Kyushu to Honshu District for Ty0418 except for the area near its center, strong rainfall with 10~30 mm/h persisted in wider regions from the western to the eastern part of the Japan Islands, resulting in the considerably large total rainfall for Ty0423. As for the case for Ty0423, the surface front with stable frontal surface was located just to the east of the Ty0423 center just before its landing at the Japan Islands. Thus, the huge moisture inflow mainly in the eastern region from the typhoon center seems to be redistributed widely over the Japan Islands area associated with the large-scale convergence around the stable frontal surface. In late October, the colder air associated with the high pressure system in the eastern Siberia can cover the northern part of the Japan Sea area as the seasonal march. Such basic field might be favorable for sustaining the synoptic-scale front just around the southern coast of the Japan Islands, even when the strong southerly wind invades associated with the typhoon approach there.
キーワード
Ty0423
Ty0418
rainfall in Japan associated with a typhoon in mid-autumn
effects of a typhoon on the synoptic climatology in Japan in October
備考
※p.18第7図が左右逆であったのを修正(Figure of the left and the right in p.18 FIG.7 was supposed to reverse. This version was corrected.)
ISSN
1340-7414
NCID
AN10506284
NAID