Some salient features of the atmosphere observed over the north Bay of Bengal during BOBMEX

Bhat, GS (2003) Some salient features of the atmosphere observed over the north Bay of Bengal during BOBMEX. In: Proceedings of the Indian Academy of Sciences - Earth & Planetary Sciences, 112 (2). pp. 131-146.

Preview

PDF Some_salien.pdf - Published Version Download (315kB)

Abstract

This paper describes the near surface characteristics and vertical variations based on the observations made at 17.5degreesN and 89degreesE from ORV Sagar Kanya in the north Bay of Bengal during the Bay of Bengal Monsoon Experiment (BOBMEX) carried out in July-August 1999. BOBMEX captured both the active and weak phases of convection. SST remained above the convection threshold throughout the BOBMEX. While the response of the SST to atmospheric forcing was clearly observed, the response of the atmosphere to SST changes was not clear. SST decreased during periods of large scale precipitation, and increased during a weak phase of convection. It is shown that the latent heat flux at comparable wind speeds was about 25-50% lower over the Bay during BOBMEX compared to that over the Indian Ocean during other seasons and tropical west Pacific. On the other hand, the largest variations in the surface daily net heat flux are observed over the Bay during BOBMEX. SST predicted using observed surface fluxes showed that 1-D heat balance model works sometime but not always, and horizontal advection is important. The high resolution Vaisala radiosondes launched during BOBMEX could clearly bring out the changes in the vertical structure of the atmosphere between active and weak phases of convection. Convective Available Potential Energy of the surface air decreased,by 2-3 kJ kg(-1) following convection, and recovered in a time period of one or two days. The mid tropospheric relative humidity and water vapor content, and wind direction show the major changes between the active and weak phases of convection.

Item Type:	Journal Article
Publication:	Proceedings of the Indian Academy of Sciences - Earth & Planetary Sciences
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Department/Centre:	Division of Mechanical Sciences > Centre for Atmospheric & Oceanic Sciences
Date Deposited:	24 Aug 2011 06:54
Last Modified:	24 Aug 2011 06:54
URI:	http://eprints.iisc.ac.in/id/eprint/40203

Actions (login required)

View Item