Characteristics and source of black carbon aerosol over Taklimakan Desert

Abstract

Black carbon (BC) and PM10 in the center of the Taklimakan Desert were online monitored in the whole year of 2007. In addition, TSP samples were also synchronously daily collected by medium-volume samplers with Whatman® 41 filters in the spring of 2007. BC in the dust aerosol was up to 1.14% of the total mass of PM10. A remarkable seasonal variation of BC in the aerosol was observed in the order of winter > spring > autumn > summer. The peak value of BC appeared at midnight while the lowest one in the evening each day, which was just the reverse of that in the urban area. The contribution of BC to the total mass of PM10 on non-dust storm days was ∼11 times of that in dust storm. Through back trajectory and principal component analysis, it was found that BC in the dust aerosol over Taklimakan Desert might be attributed to the emission from the anthropogenic activities, including domestic heating, cooking, combustion of oil and natural gas, and the medium-range transport from those oases located in the margins of the desert. The total BC aerosol from the Taklimakan Desert to be transported to the eastward downstream was estimated to be 6.3 × 104 ton yr−1.