Northward Ageostrophic Winds Associated with a Tropical Cyclone. Part 2: Moisture Transport and Its Impact on PRE
Northward Ageostrophic Winds Associated with a Tropical Cyclone. Part 2: Moisture Transport and Its Impact on PRE
复制标题
与热带气旋相关的北向地转风。
DOI：
10.2151/sola.2020-034
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发表时间：
2020
期刊：
影响因子：
1.9
通讯作者：
T. Matsunobu
中科院分区：
文献类型：
--
作者：
Kazuo Saito;T. Matsunobu
当热带气旋（TC）存在于南海岸海域时，通常会出现强降雨。这些台风前的降雨与热带气旋前向北的水汽输送有关。本文研究了台风T0918 （Melor）伴随的地转风向北的水汽输送及其对PRE的影响。根据之前的研究（Saito 2019）进行的数值模拟，我们分析了复制地转风和地转风对北的水分通量。虽然高空主要以偏南的地转风为主，但在3 km以上的中高层，地转风对向极地方向的水汽输送有促进作用。为了观察地转水汽输送对PRE的影响，我们进行了日本西部南岸海域中高层模式水汽减少的敏感性实验。当不考虑地转风对水分通量的贡献时，日本西部的降水减少了约30%。这一结果表明，与TC相关的北向地转风通过湿润中高层大气来增强PRE。在TEST中为正数，
Heavy rainfalls often occur when a tropical cyclone (TC) exists on the sea off the south coast. These pre-typhoon rainfalls (PRE) is associated with the northward moisture transport ahead of the TC. In this paper, we examine the northward moisture transport by the ageostrophic winds associated with typhoon T0918 (Melor) and its impact on PRE. According to a numerical simu-lation conducted in the previous study (Saito 2019), we analyzed the northward moisture fluxes by reproduced geostrophic and ageostrophic winds. Although the southerly ageostrophic winds are dominant mainly in the upper levels, the ageostrophic winds contribute to enhance the poleward water vapor transport for the upper and middle levels above 3 km. To see the impact of the ageostrophic moisture transport on PRE, we conducted a sensitivity experiment where the model moisture in middle and upper levels over the sea off the south coast of western Japan was reduced. Precipitation over western Japan was decreased about 30% when the contributions in moisture fluxes by ageostrophic winds were removed. This result suggests that the northward ageostrophic winds associated with a TC enhance PRE by moistening the middle and upper atmosphere. a positive with the of of in TEST,
影响因子：
4.3
作者：
Nakanishi, Mikio;Niino, Hiroshi
通讯作者：
Niino, Hiroshi