Relationships between lightning activity and various thundercloud parameters: satellite and modelling studies
Relationships between lightning activity and various thundercloud parameters: satellite and modelling studies
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DOI：
10.1016/s0169-8095(99)00009-5
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发表时间：
1999-07-01
影响因子：
5.5
通讯作者：
Gadian, AM
中科院分区：
文献类型：
--
作者：
Baker, MB;Blyth, AM;Gadian, AM
Baker等人开发的闪电频率模型[Baker，M.B.，克里斯蒂安，H. J.，莱瑟姆，J.，1995.计算研究了闪电频率与其它雷暴云参数之间的关系，Q。J. R.陨石。第二节，121，1525-1548]已被完善和扩展，在努力提供一个更现实的框架，从计算上检查闪电频率f（这是现在例行测量从卫星，使用美国宇航局/MSFC光学瞬态探测器（OTD））和各种云的物理参数之间可能存在的关系。具体地说，利用了上级或更全面的表示：（1）通过Hallett-Mossop（H-M）过程的冰川作用;（2）模型云的上升气流结构;（3）模型云的液态水含量结构;（4）反转温度T-rev在影响闪电特征中的作用;（5）闪电引发的临界击穿场;（6）模型云冰晶砧的电学特性。虽然我们的扩展研究对这个问题产生了一些新的见解，但f和其他参数之间关系的基本模式与Baker等人（1995）的报告非常接近。对T-rev的更详细的处理在某种程度上限制了如果云通过H-M冰川作用时可能产生反极性闪电的条件范围，但证实了早先的结论，即如果冰川作用是弗莱彻类型的，这种闪电就不会发生。计算结果初步支持的假设，卫星测量的f可能被用来确定积雨云砧的冰含量的值：一个参数的气候重要性。OTD的成功启动和持续令人满意的运作[Christian，H. J.，古德曼，S.，1992.从空间对闪电的全球观测，第9届国际大气电会议论文集，彼得堡，pp. 316-321; Christian，H.J.，布莱克西，R. J.，古德曼，S. J.，1992.用于地球观测系统的闪电成像传感器。NASA技术备忘录，4350]使它成为可能-以高精度-测量闪电的位置，发生时间和频率f在地球表面的广泛地区。测量的全球闪电分布和相关的雷击辐射表明：闪电活动在热带地区特别明显，在陆地上比在海洋上大得多，并表现出很大的季节性变化;闪电辐射往往在海洋上更大，当闪电活动高，更大的北方半球冬季比夏季。(C)1999 Elsevier Science B. V.保留所有权利。
The lightning frequency model developed by Baker et al. [Baker, M.B., Christian, H.J., Latham, J., 1995. A computational study of the relationships linking lightning frequency and other thundercloud parameters, Q. J. R. Meteorol. Sec., 121, 1525-1548] has been refined and extended, in an effort to provide a more realistic framework from which to examine computationally the relationships that might exist between lightning frequency f (which is now being routinely measured from a satellite, using the NASA/MSFC Optical Transient Detector (OTD)) and a variety of cloud physical parameters. Specifically, superior or more comprehensive representations were utilised of: (1) glaciation via the Hallett-Mossop (H-M) process; (2) the updraught structure of the model cloud; (3) the liquid-water-content structure of the model cloud; (4) the role of the reversal temperature T-rev in influencing lightning characteristics; (5) the critical breakdown field for lightning initiation; and (6) the electrical characteristics of the ice crystal anvil of the model cloud. Although our extended studies yielded some new insights into the problem, the basic pattern of relationships between f and the other parameters was very close to that reported by Baker et al. (1995). The more elaborate treatment of T-rev restricted somewhat the range of conditions under which reverse-polarity lightning could be produced if the cloud glaciated via H-M, but confirmed the earlier conclusion that such lightning would not occur if the glaciation was of the Fletcher type. The computations yielded preliminary support for the hypothesis that satellite measurements of f might be used to determine values of the ice-content of cumulonimbus anvils: a parameter of climatological importance. The successful launch and continuing satisfactory functioning of the OTD [Christian, H.J., Goodman, S., 1992. Global observations of lightning from space, Proc. 9th Int. Conf. on Atmospheric Electricity, St. Petersburg, pp. 316-321; Christian, H.J., Blakesee, R.J., Goodman, S.J., 1992. Lightning imaging sensor (LIS) for the earth observing system. NASA Tech. Memorandum, 4350] make it possible-with a high degree of precision-to measure lightning location, occurrence time and frequency f over extensive areas of the Earth's surface. Measured global distributions of lightning and associated lightning stroke radiance demonstrate that: lightning activity is particularly pronounced over the tropics, much greater over land than over the oceans, and exhibits great seasonal variability; lightning radiance tends to be greater over the oceans, less when lightning activity is high, and greater in the Northern Hemisphere winter than summer. (C) 1999 Elsevier Science B.V. All rights reserved.