Atmospheric boundary layer during ARMEX-2002 at stationary positions - comparative study

Abstract

A study has been carried out to explore the salient features of the Atmospheric Boundary Layer (ABL) over the eastern Arabian Sea regions during the summer monsoon season of 2002. For this purpose the aerological observations and surface meteorological observations collected onboard ORV Sagar Kanya during the Phase-I of ARMEX-2002 for the two stationary positions (30 June-10 July and 22 July – 5 August 2002) have been considered. Utilizing these observations the vertical structure of the Atmospheric Boundary Layer and the temporal variation of different surface parameters has been investigated. The results showed prominent diurnal variation in different surface meteorological parameters. The study also revealed that there is no influence of the offshore trough on the vertical structure of the Atmospheric Boundary Layer. The ABL showed multilayered structure with shallow sub cloud layer, deep cloud layer, weak stable layer and the ABL extending up to higher levels in the presence of the cyclonic circulation (2-4 August 2002). Whereas the ABL is associated with deep sub cloud layer, shallow cloud layer, strong stable layer (inversion layer) and shallow ABL depth under the influence of weak offshore trough observed along the west coast of India.