Aerosol black carbon over a tropical coastal location: response to mesoscale and synoptic scale processes

Abstract

Continuous ground based measurements on the mass concentration of aerosol Black Carbon (BC) were carried out during January 2004 to December 2004, at a tropical coastal station, Trivandrum, India. These are examined to delineate the response of BC to changes in synoptic as well as mesoscale circulations. BC shows a diurnal (with a nocturnal peak and afternoon low) and seasonal variations (highest during local winter when dry conditions prevail, with a continental airmass and sparse precipitation, and lowest during monsoon when the airmass is marine in nature and precipitation is widespread). The diurnal varations are compared with those from an inland station Kharagpur (at the Northeast part of India) during a campaign mode experiment and the differences are outlined for the month of December 2004. Though the diurnal variations are similar, BC concentrations at Kharagpur were significantly higher than that at Trivandrum for the month of December.