Study of the Oceanic Heat Budget Components over the Arabian Sea during the Formation and Evolution of Super Cyclone, Gonu

Abstract

Oceans play a vital role in the global climate system. They absorb the incoming solar energy and redistribute the energy through horizontal and vertical transports. In this context it is important to investigate the variation of heat budget components during the formation of a low-pressure system. In 2007, the monsoon onset was on 28th May. A well- marked low-pressure area was formed in the eastern Arabian Sea after the onset and it further developed into a cyclone. We have analysed the heat budget components during different stages of the cyclone. The data used for the computation of heat budget components is Objectively Analyzed air-sea flux data obtained from WHOI (Woods Hole Oceanographic Institution) project. Its horizontal resolution is 1 ° × 1 ° . Over the low-pressure area, the latent heat flux was 180 Wm ﹣ 2 . It increased to a maximum value of 210 Wm ﹣ 2 on 1st June 2007, on which the system was intensified into a cyclone (Gonu) with latent heat flux values ranging from 200 to 250 Wm ﹣ 2 . It sharply decreased after the passage of cyclone. The high value of latent heat flux is attributed to the latent heat release due to the cyclone by the formation of clouds. Long wave radiation flux is decreased sharply from 100 Wm ﹣ 2 to 30 Wm ﹣ 2 when the low-pressure system intensified into a cyclone. The decrease in long wave radiation flux is due to the presence of clouds. Net heat flux also decreases sharply to ﹣ 200 Wm ﹣ 2 on 1st June 2007. After the passage, the flux value increased to normal value (150 Wm ﹣ 2 ) within one day. A sharp increase in the sensible heat flux value (20 Wm ﹣ 2 ) is observed on 1st June 2007 and it decreased there after. Short wave radiation flux decreased from 300 Wm ﹣ 2 to 90 Wm ﹣ 2 during the intensification on 1st June 2007. Over this region, short wave radiation flux sharply increased to higher value soon after the passage of the cyclone.