资源环境科技发展态势分析平台

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 degrees 34N, 88 degrees 22E), 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 30min before the onset of rain can approximate impending rain accumulation.