Black carbon aerosols over coastal Antarctica and its scavenging by snow during the Southern hemispheric summer

• Main Authors: Chaubey, Jai Prakash, Krishnamoorthy, K., Babu, S. Suresh, Nair, Vijayakumar S., Tiwari, Anoop
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2010
• Subjects: Antarctic; Indian; Larsemann Hills; Maitri; Antarc*; Antarctica
• Online Access: http://repository.ias.ac.in/17218/; http://www.agu.org/pubs/crossref/2010/2009JD013381.shtml

Mass concentrations of aerosol black carbon (BC) and of the composite (total) aerosols (M B and M T , respectively) were measured over two Antarctic locations, Maitri [70°S, 12°E, 123 m mean sea level (msl)] and Larsemann Hills (LH; 69°S, 77°E, 48 m msl) as a part of the twenty-eighth Indian Scientific Expedition to Antarctica during the Southern Hemispheric summer of 2009. Despite being very low compared to Northern Hemisphere locations, M B and its mass mixing ratio to the total aerosols were much high over Maitri (~75 ng m -3 and 2%) compared to LH (13 ng m -3 and 0.2%). At both locations, M B fell abruptly after blizzards, after which the values reduced to nearly half the pre-blizzard values. This BC scavenging by snow can lead to change in snow albedo and has strong climate implications. The Angstrom exponent (α abs ) estimated from the spectral values of absorption coefficients (σ abs ) is found to vary from 0.5 to 1, indicating higher a BC-to-organic carbon ratio typical of fossil fuel origin.