Atmospheric boundary layer observations on the East Coast at Kalpakkam using Doppler mini-sodar during different seasons

Abstract

A phased array Doppler Mini-Sodar has been installed at Anupuram near Kalpakkam nuclear site during the Coastal Atmospheric Boundary Layer Experiments (CABLE) carried out on the east coast of India. Mini-Sodar was used to measure the wind profile and investigate the coastal boundary layer development due to land-sea breeze circulation for the study of coastal dispersion of pollutants. The atmospheric boundary layer, its variability during SW (August 13, 14 : ARMEX I and September 3, 7, 11, 14) and pre-monsoon period (April 27, 28 : ARMEX II) 2003 has been studied. Large wind direction change and  high vertical velocity variance were observed  during the onset of sea breeze. The Thermal Internal Boundary Layer (TIBL) height has been found to increase progressively with season: summer - 170 m, SW monsoon - 210 m and NE monsoon - 325 m  whereas the Nocturnal Boundary Layer (NBL)        height decrease progressively during the corresponding period: summer - 370 m, SW monsoon - 340 m and NE monsoon - 210 m.