著者

Akihiro Hashimoto Hiroki Motoyoshi Narihiro Orikasa Ryohei Misumi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

vol.16, pp.51-56, 2020 (Released:2020-03-25)

参考文献数

36

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We have developed a new method of diagnosing the characteristics of ice particles using a bulk microphysics model. Our model tracked the mass compositions of different classes of ice particles, using their microphysical process of origin, such as water vapor deposition and riming. The mass composition from depositional growth was further divided into six components by the temperature and humidity ranges corresponding to the typical growth habits of ice crystals. In test simulations, the new framework successfully revealed the influences of riming and depositional growths of ice particles within clouds and on surface snowfall. The new approach enables weather prediction models to provide much more information on the characteristics of ice particles regarding crystal habits and the extent of riming.

著者

Ryohei MISUMI Namiko SAKURAI Takeshi MAESAKA Shin-ichi SUZUKI Shingo SHIMIZU Koyuru IWANAMI

出版者

Meteorological Society of Japan

雑誌

気象集誌. 第2輯 (ISSN:00261165)

巻号頁・発行日

vol.96A, pp.51-66, 2018 (Released:2018-02-19)

参考文献数

26

被引用文献数

4

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Convective storms are frequently initiated over mountains under weak synoptic forcing conditions. However, the initiation process of such convective storms is not well understood due to a lack of observations, especially the transition process from non-precipitating cumuli to precipitating convective clouds. To investigate the initiation process, we conducted observations around the mountains in the Kanto region, Japan on 18 August 2011 using a 35 GHz (Ka-band) Doppler radar and a pair of digital cameras. The evolution of convective clouds was classified into three stages: convective clouds visible but not detected by the Ka-band radar (stage 0), convective clouds detectable by the Ka-band radar with reflectivity below 15 dBZ (stage 1), and convective clouds accompanied by descending echoes corresponding to precipitation (stage 2). During the transition process from stage 1 to stage 2, weak radar echoes rose to the higher level and reflectivity rapidly increased. This phenomenon suggests that drizzle particles produced in a preexisting convective cloud were lifted by a newly developed updraft, and raindrops were formed rapidly by coalescence of the drizzle particles and cloud droplets. This hypothetical process explains the precipitation echo formation in the lower layer frequently observed in the mountainous area in the Kanto region.

著者

Akihiro Hashimoto Hiroki Motoyoshi Narihiro Orikasa Ryohei Misumi

出版者

Meteorological Society of Japan

雑誌

SOLA (ISSN:13496476)

巻号頁・発行日

pp.2020-009, (Released:2020-03-02)

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We have developed a new method of diagnosing the characteristics of ice particles using a bulk microphysics model. Our model tracked the mass compositions of different classes of ice particles, using their microphysical process of origin, such as water vapor deposition and riming. The mass composition from depositional growth was further divided into six components by the temperature and humidity ranges corresponding to the typical growth habits of ice crystals. In test simulations, the new framework successfully revealed the influences of riming and depositional growths of ice particles within clouds and on surface snowfall. The new approach enables weather prediction models to provide much more information on the characteristics of ice particles regarding crystal habits and the extent of riming.