Characteristics of an Extreme Rainfall Event in Kyushu District, Southwestern Japan in Early July 2020
Characteristics of an Extreme Rainfall Event in Kyushu District, Southwestern Japan in Early July 2020
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DOI：
10.2151/sola.2020-044
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发表时间：
2020-12-24
期刊：
影响因子：
1.9
通讯作者：
Mashiko, Wataru
中科院分区：
文献类型：
--
作者：
Hirockawa, Yasutaka;Kato, Teruyuki;Mashiko, Wataru
2020年7月初，日本西南部九州地区发生极端降雨事件，降水量超过1，000毫米。特别是在九州中部的熊川周围形成的一个拉长和停滞的中尺度对流系统产生了13小时内降水量大于600 mm的局部暴雨。利用雷达/雨量计分析的降水量分布（RAP）研究了这一极端降雨事件的特征，并与2009-2019年暖季（4 - 11月）的降水量进行了统计比较。结果如下：（1）提取了9个线性平稳型暴雨落区（LS-IRAs），其中2个LS-IRAs的时空尺度分别超过270 km和10 h，最大RAP超过100 mm，与以往的极端降水事件相当，（4）超过200 mm的3小时累积降水量比以往增多，（5）九州岛周边地区的5天累积降水量为2009年以来最大。这项研究还表明，大面积的综合降水量主要是由广泛的降水系统与贝恩锋，而9个LS-HRA显着贡献了局部暴雨。
An extreme rainfall event brought precipitation amounts exceeding 1000 mm in Kyushu district, southwestern Japan, in early July 2020. Especially, an elongated and stagnated mesoscale convective system formed around the Kuma River in central Kyushu district produced localized heavy rainfall with precipitation amounts larger than 600 mm in 13 hours. Characteristics of this extreme rainfall event were investigated using distributions of radar/raingauge-analyzed precipitation amounts (RAP) and statistically compared with those during the warm seasons (April-November) in 2009-2019. The results are shown as follows; (1) nine heavy rainfall areas of linear-stationary type (LS-IRAs) were extracted, (2) spatial and temporal scales of two LS-HRAs among them respectively exceeded 270 km and 10 hours, (3) the maximum RAP exceeding 100 mm in LS-HRAs were comparable to those in previous extreme rainfall events, (4) large accumulated three-hour precipitation amounts exceeding 200 mm were more frequently observed than those in the previous events, and (5) the accumulated five-day precipitation amount integrated around Kyushu Island was the largest since 2009. This study also showed that the large area-integrated precipitation amount was produced mainly from widespread precipitation systems associated with the Bain front, while the nine LS-HRAs significantly contributed localized heavy rainfall.