- 著者
- Tetsuya Takemi
- 出版者
- (公社)日本気象学会
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- vol.10, pp.158-162, 2014 (Released:2014-10-10)
- 参考文献数
- 14
- 被引用文献数
- 1 8
This study investigates the characteristics of local-scale afternoon rainfall and its environmental conditions in and around the Nobi Plain under synoptically undisturbed conditions in summer by using operational meteorological data. The analysis of radar/raingauge analyzed precipitation data revealed that strong rainfall occurs over the mountain slopes in late afternoon and in the northern part of the Nobi Plain in early evening, while light rain frequently occurs around the mountain peaks in early afternoon. Examining mesoscal analysis data indicated that the primary difference in the environmental conditions that distinguish between rain and no-rain days is middle-level moisture field, with moister condition being found on rain days. Because of the significant difference in the middle-level moisture, stability index is useful in distinguishing the environmental conditions between rain and no-rain days.
- 著者
- Tetsuya Takemi
- 出版者
- Meteorological Society of Japan
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- pp.2018-027, (Released:2018-10-12)
- 被引用文献数
- 35
An extreme, damaging rainfall occurred in northern Kyushu in July 2017. Whether such an extreme rainfall is quantitatively captured by numerical models is a challenging issue. We investigate the influences of terrain representation in simulating a stationary convective system and the resulting heavy rainfall for this case by conducting a series of 167-m-resolution numerical experiments. By employing a high-resolution elevation dataset as well as a double-moment cloud microphysics scheme, the control experiment successfully reproduced the stationary, linear-shaped convective system and the associated heavy rainfall. When the model terrain was created by a coarser-resolution elevation dataset, the 167-m-resolution experiment underestimated the accumulated rainfall, because of discretely developing convection and weaker intensities of the rainfall.These impacts of the terrain representation were confirmed to be robust through conducting another experiments with a different microphysics scheme. The representation of model terrains is critically important in simulating stationary convective systems and quantitatively the resulting heavy rainfall.
- 著者
- Rui Ito Tetsuya Takemi Osamu Arakawa
- 出版者
- (公社)日本気象学会
- 雑誌
- SOLA (ISSN:13496476)
- 巻号頁・発行日
- vol.12, pp.100-105, 2016 (Released:2016-04-22)
- 参考文献数
- 23
- 被引用文献数
- 5 38
Typhoon Songda (2004), while undergoing an extratropical transition and reintensification over the Sea of Japan, spawned serious damages over forest areas in the northern part of Japan. To clarify influences of anticipated global warming on the typhoon hazard in high-latitude regions, we carried out numerical experiments on Typhoon Songda in a current climate and a pseudo global warming climate and examined the impacts of climate change on the typhoon intensify and windstorms for the region. The typhoon intensity at its maturity becomes stronger in a warming climate, and the typhoon while passing over the Sea of Japan weakens more rapidly in the warming climate. Thus the strong wind over the northern part of Japan in the warming climate also becomes weaker. We examined atmospheric environmental factors in the higher-latitude region: sea surface temperature, vertical shear, and meridional gradient of temperature. It was found that the environmental meridional gradient of temperature at the 500 hPa level is smaller in the warming climate than in the current climate, which indicates that the baroclinicity becomes weak under global warming. The weak baroclinicity makes the typhoon environment unfavorable for the extratropical transition, and therefore, possibly reduces the severity of typhoon wind in northern Japan.