Carbonaceous aerosol in La Gran Sabana, Canaima National Park, Venezuela
Milexi
Pacheco, Instituto Venezolano de Investigaciones Cientificas, IVIC, mipachec@ivic.ve
(Presenting)
Eugenio
Sanhueza, Instituto Venezolano de Investigaciones Cientificas, IVIC, esanhuez@ivic.ve
Due to potential importance in the carbon cycle and global climate, increasing attention has been given to study atmospheric black carbon (BC). Very few estimates of the relative contribution of BC to the different compartments of the carbon cycle are available to date. We selected a remote place in Venezuela, La Gran Sabana, Canaima National Park, located nearby the northern border of the Amazon Forest, to study carbonaceous atmospheric aerosol. Size fractionated particles were collected using a cascade impactor. Total carbon (TC), organic carbon (OC) and BC were quantified by an optimized two steps thermal method. The mean TC was 3.2 ± 0.5 ug/m3, which is in the same order of magnitude as those found in remote continental atmospheres. The results show that carbon aerosol is mainly present in the fine fraction. The BC concentration was 1.3 ± 0.3 ug/m3; 14%, 29% and 56 % were in large, course and fine particle size, respectively. No correlation between nss-K+ and BC was found, suggesting that BC is not coming from local biomass burning. Comparing with the Amazon forest, relatively low OC concentration was found in La Gran Sabana site, likely due to a low secondary production of organic particles.