Enhanced layer of black carbon in a north Indian industrial city

Abstract

During a comprehensive aerosol field campaign as part of Indian SpaceResearch Organization Geosphere Biosphere Programme (ISRO-GBP),aircraft measurements of vertical profiles of aerosol black carbon (BC)were made during winter, for the first time, at Kanpur (80 degrees 20'Eand 26 degrees 26'N), an urban industrial location in Northern India.Two vertical profiling from the same day (morning and afternoon) of BCshowed that BC decreases with height up to similar to 600 m and thenincreases up to 900 m before becoming more or less constant withheight. Potential temperature profile, derived from concurrentmeasurements of temperature, shows a stable layer at the same altitudewhere BC shows increased concentration. This vertical structure ofboundary layer was further confirmed by separate temperature andrelative humidity profiles obtained from balloonsondes during December.The increased BC at similar to 900 m suggests the presence of enhancedBC layer, which will have significant implications to BC radiativeforcing and modifying cloud properties