A new paradigm of seasonal prediction of the lightning over India
Abstract
Thunderstorm is a very severe weather phenomenon, usually associated with lightning, flash floods and hails. A reliable forecast of severe lightning is crucial. Lightning activity is a severe weather phenomenon characterized by strong convection (Van Den Broeke et al., 2005), where instability, strong vertical updraft, wind shear and availability of moisture are prominent. The lightning flash rate can be related to the maximum vertical updraft velocity, cloud dimension (where graupel exists along with snow, ice, and cloud water) cloud top height (Williams, 1985) etc. Now the question arises among scientists that 'whether the seasonal forecast of lightning over India is possible?' Thus we put up a hypothesis that seasonal lightning flash is partly predictable, if sub-seasonal (synoptic + intraseasonal) fluctuations of lightning flash is tied to the slowly varying forcings (e.g., El Niño and Southern Oscillation, ENSO). In this study, we have tried to investigate the possible relationship of lightning with the large scale modes of variability (such as rainfall ENSO etc.) The mean pattern of lightning over global tropics during pre-monsoon (March-May, MAM) and monsoon (June-September, JJAS) by using the lightning data from TRMM LIS/OTD for a period of seventeen years (1997-2013) and rainfall data from GPCP shows that lightning over land regions are associated with the rainfall. It is noticed that Central Africa has most intense lightning and the mean JJAS rainfall is also significant in the same region amidst Africa continent. Similar relation between rainfall and lightning is observed over India and northern Latin America. Mean pattern of lightning during MAM also has good pattern correlation with mean MAM rainfall. The cloud ice content and cloud water content for both JJAS and MAM seasons seems to be well correlated with mean seasonal (JJAS and MAM) lightning over most of the region. Strong vertical updrafts are observed for the region averaged over tropical latitudes (30S-30N) over the lightning prone regions. Apart from these findings, this study demonstrates that the synoptic variance of lightning flash during MAM and JJAS are correlated with ENSO, which gives us a hope for seasonal forecast of lightning flash using high resolution climate model.
Keywords: Lightning flash, thunderstorm, variance, ENSO- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMAE21B3073M
- Keywords:
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- 3304 Atmospheric electricity;
- ATMOSPHERIC PROCESSES;
- 3324 Lightning;
- ATMOSPHERIC PROCESSES;
- 0694 Instruments and techniques;
- ELECTROMAGNETICS