The lightning activity associated with the dry and moist convections in the Himalayan Regions

Abstract

Lightning activity in the dry environment of northwest India and Pakistan (NW) and in the moist environment of northeast India (NE) has been examined from the Optical Transient Detector and Lightning Imaging Sensor data obtained from the Tropical Rainfall Measuring Mission satellite during 1995–2010. In the NW region, seasonal variation of flash rate is annual with a maximum in July but is semi‐annual with a primary maximum in April and a secondary maximum in September, in the NE region. On diurnal scale, flash rate is the maximum in the afternoons, in both the NE and NW regions. The correlation of flash rate with convective parameters, viz. surface temperature, convective available potential energy (CAPE) and outgoing long‐wave radiation is better with convective activity in the NW than in the NE region. Mean value of aerosol optical depth at 550 nm is ~ 26% higher and is highly correlated with flash rate in NW as compared to that in NE. Results indicate that CAPE is ~ 120 times more efficient in NW than in the NE region for production of lightning. The empirical orthogonal function analysis of flash rate, surface temperature, and CAPE shows that variance of lightning activity in these regions cannot be fully explained by the variance in the surface temperature and CAPE alone, and that some other factors, such as orographic lifting, precipitation, topography, etc., may also contribute to this variance in these mountainous regions. Further, the increase in CAPE due to orographic lifting in the Himalayan foothills in the NE region may contribute to ~ 7.5% increase in lightning activity. Relative roles of the thermally induced and moisture‐induced changes in CAPE are examined in these regions. This study merely raises the questions, and that additional research is required for explaining the fundamental reasons for the reported observations here.

Using cloud ice flux to parametrise large-scale lightning

“…India shows the greatest seasonal and interannual variation. There is substantial evidence linking these variations in lightning activity to monsoon seasons (Kumar and Kamra, 2012;Pawar et al, 2012;Chaudhuri and Middey, 2013;Penki and Kamra, 2013). The ability of models to represent the monsoon as well as the links between the monsoon and lightning is important to consider when studying lightning in India.…”

“…It could also be related to the occurrence of lightning in relation to other features of storms. It has been discussed in some papers that lightning peak months precede the rainfall peak months in monsoonal regions (Chaudhuri and Middey, 2013;Penki and Kamra, 2013). This may be relevant to variables such as convective rain and cloud-top height; however, one would expect the use of upward ice flux to begin to correct the delay.…”

Microphysical processes and hydrometeor distributions associated with thunderstorms over India: WRF (cloud-resolving) simulations and validations using TRMM

“…The monthly variation of lightning activity reveals that most of the regions other than northwest India (NW) show maximum lightning flash during pre-monsoon months (March-April-May). Maxima in lightning flash in NW region are found in the monsoon months (Penki and Kamra 2013). From various studies such as Kandalgaonkar et al (2005) and Ranalkar and Chaudhari (2009), it is established that spatiotemporal variability of lightning over Indian region is related to convective activity, large-scale circulation, land mass gradient and orography of that region.…”

“…In the Southern Peninsula, the preferred time for occurrence of TS is 0900-1200 UTC (Litta and Mohankumar 2007). From the diurnal variability of flash rate in NW region, it is observed that low values of flash rate occur during morning hours, which increase by noon and remain high throughout the afternoon and early night (Penki and Kamra 2013).…”

Lightning and convective rain over Indian peninsula and Indo-China peninsula

“…Tibetan Plateau and steeper orography contribute to more vigorous updrafts leading to high cloud tops and enhanced lightning flashes in thunderclouds (Williams, 2001;Penki and Kamra, 2013). Kriplani and Kulkarni (1998) reported that the southwest monsoon carrying enormous quantities of moisture from the Bay of Bengal and orography of the region R 2 are the main cause of high precipitation.…”