DOI: 10.1002/2016JD026283
论文题名: Relationship between cloud-to-ground lightning polarity and the space-time distribution of solid hydrometeors in isolated summer thunderclouds observed by X-band polarimetric radar
作者: Kouketsu T. ; Uyeda H. ; Ohigashi T. ; Tsuboki K.
刊名: Journal of Geophysical Research: Atmospheres
ISSN: 2169897X
出版年: 2017
卷: 122, 期: 16 起始页码: 8781
结束页码: 8800
语种: 英语
英文关键词: cloud-to-ground lightning polarity
; hydrometeor classification
; isolated summer thundercloud
; polarimetric radar observation
英文摘要: To understand the charge distribution in thunderclouds associated with solid hydrometeors, the relationship between cloud-to-ground (CG) lightning polarity and the space-time distribution of solid hydrometeors for isolated summer thunderclouds in Japan is examined using X-band polarimetric radar. Hydrometeor classification was conducted to examine the space-time distribution of dry snow, ice crystal, dry graupel (DG), and wet graupel in thunderclouds. Two thunderstorm cases were selected for analysis: 26 July 2010, which generated few positive CG flashes, and 25 August 2010, which generated positive CG flashes in the reflectivity cores. In both cases, negative CG flashes were observed in all reflectivity cores when a large volume of DG was identified above the height of −10°C level. This is consistent with previous studies showing that graupel particles have a negative charge below temperatures of −10°C. Reflectivity cores with positive CG flashes had a large volume of DG up to high altitudes (around or above the −45°C level). Further, reflectivity cores that sustained large DG volumes at high altitudes had a relatively large number of positive CG flashes. The top height of the DG volume reached lower altitudes for reflectivity cores without positive CG flashes compared with those with positive CG flashes. These results suggest that the persistence of graupel particles in reflectivity cores at high altitudes, implying the existence of strong updraft, is a necessary condition for positive CG flashes in summer thunderclouds. This effect would likely be caused by the positively charged graupel particles under high rime accretion rates. ©2017. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/62592
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Japan; National Institute of Information and Communications Technology, Tokyo, Japan
Recommended Citation:
Kouketsu T.,Uyeda H.,Ohigashi T.,et al. Relationship between cloud-to-ground lightning polarity and the space-time distribution of solid hydrometeors in isolated summer thunderclouds observed by X-band polarimetric radar[J]. Journal of Geophysical Research: Atmospheres,2017-01-01,122(16)