印度北部潮湿地区和干旱地区的闪电特征及其与气溶胶的关系

Lightning Characteristics Over Humid Regions and Arid Regions and Their Association With Aerosols Over Northern India.

作者信息

Jnanesh S P, Lal D M, Gopalakrishnan V, Ghude Sachin D, Pawar Sunil D, Tiwari S, Srivastava Manoj K

机构信息

Indian Institute of Tropical Meteorology, Pune, India.

Department of Geophysics, Banaras Hindu University, Varanasi, India.

出版信息

Pure Appl Geophys. 2022;179(4):1403-1419. doi: 10.1007/s00024-022-02981-6. Epub 2022 Feb 28.

DOI:10.1007/s00024-022-02981-6

PMID:35250099

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC8883017/

Abstract

UNLABELLED

The association between aerosol and lightning has been investigated with long-term decadal data (2005-2014) for lightning, aerosol optical depth (AOD), relative humidity, and effective cloud droplet size. To understand the complex relationship between aerosol and lightning, two different regions with different climatic and weather conditions, a humid region R1 (22°-29° N, 89°-92° E) and an arid region R2 (23°-28° N, 70°-76° E) of northern India, were chosen for the study domain. The results show that lightning activity was observed to occur more over the humid region R1, i.e., 1141 days (1/3 of total days), than over the arid region R2, i.e., 740 days (1/5 of total days). Also, over the humid region R1, the highest lightning flash density was recorded as nearly 4.6 × 10 flashes/km/day observed for 18 days (1.5%); on the contrary, over the arid region R2, the maximum lightning flash density was observed to be 2.5 × 10 flashes/km/day and occurred for about 22 days (2.9%). The analysis shows that a nonlinear relationship exists between aerosol and lightning with a highly associated influence of relative humidity. A very significant positive and negative co-relation that varies with relative humidity has been observed between AOD and lightning for both humid and arid regions. This shows relative humidity is the key factor in determining the increase or decrease of lightning activity. This study also shows that the larger the cloud droplet size, the higher the relative humidity and vice versa. This study emphasizes that aerosol concentration in the atmosphere influences cloud microphysics by modulating the size of cloud droplets and thereby regulating the lightning frequency. The atmospheric humidity is the driving factor in deciding the positive or negative co-relationship between aerosol and lightning.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s00024-022-02981-6.

摘要

未标注

利用长达十年的数据（2005 - 2014年）对闪电、气溶胶光学厚度（AOD）、相对湿度和有效云滴大小之间的关联进行了研究。为了解气溶胶与闪电之间的复杂关系，选择了印度北部气候和天气条件不同的两个区域，一个湿润区域R1（北纬22° - 29°，东经89° - 92°）和一个干旱区域R2（北纬23° - 28°，东经70° - 76°）作为研究区域。结果表明，观察到闪电活动在湿润区域R1比在干旱区域R2更为频繁，即湿润区域R1有1141天（占总天数的1/3），而干旱区域R2有740天（占总天数的1/5）。此外，在湿润区域R1，记录到的最高闪电闪密度接近4.6×10次/千米/天，出现了18天（占1.5%）；相反，在干旱区域R2，最大闪电闪密度为2.5×10次/千米/天，出现了约22天（占2.9%）。分析表明，气溶胶与闪电之间存在非线性关系，相对湿度对其有高度相关的影响。在湿润和干旱区域，均观察到AOD与闪电之间存在随相对湿度变化的非常显著的正相关和负相关。这表明相对湿度是决定闪电活动增减的关键因素。该研究还表明，云滴尺寸越大，相对湿度越高，反之亦然。该研究强调，大气中的气溶胶浓度通过调节云滴大小影响云微物理，从而调节闪电频率。大气湿度是决定气溶胶与闪电之间正相关或负相关关系的驱动因素。