Electric Field Variation in Clear and Convective Conditions at a Tropical Urban Location

Abstract

The behavior of atmospheric electric field in terms of potential gradient (PG) has been studied during the period of 2013 and 2014 at a tropical and urban location Kolkata (22°34′N, 88°22′E), India. The clear‐weather PG is influenced by varying concentration of black carbon, which is a major pollutant in urban atmosphere. The diurnal variation of the clear‐day PG follows that of the black carbon concentration in all the seasons. It is found that cloud base height and liquid water path correlate well with the PG change in convective events. It is shown that during a convective event the PG change measured over 10‐min interval about 30 min before the onset of rain can approximate impending rain accumulation.

Gravity Wave Activities Associated With Convective Phenomena at a Tropical Location Near Land‐Sea Boundary

“…The mean E t during the winter months (19 J/kg) is the lowest seasonal value. E t is also high during the premonsoon month, May which is often characterized by convective events over the present location (Jana & Maitra, ).…”

“…The atmospheric processes at Kolkata are expected to be influenced by both land and oceanic events. Kolkata experiences a very active monsoon period where severe convective processes are observed (Jana et al, 2018;Jana & Maitra, 2019;Rakshit et al, 2017). Also, cyclones generated in the Bay of Bengal during premonsoon and postmonsoon hit the nearest coast.…”

Influence of Aerosols on Atmospheric Gravity Waves at an Urban Tropical Location

“…Heat absorbing aerosols perturb the Earth's radiation budget by absorbing the solar radiation ((IPCC), 2001, Jacobson, 2001. Kolkata being a tropical metropolis, the pollutant aerosols which dominate the present location can go above the normal boundary layer due to pre-monsoon convection, and trapping of aerosol occur at that height causing perturbation in temperature profile (Talukdar et al, 2017;Jana et al, 2019). Changes in temperature profile also impact the wind profile resulting in increased wind perturbations.…”