title: Penetration of biomass-burning emissions from South Asia through the Himalayas: new insights from atmospheric organic acids.
abstract: High levels of carbonaceous aerosol exist over South Asia, the area adjacent to the Himalayas and Tibetan Plateau. Little is known about if they can be transported across the Himalayas, and as far inland as the Tibetan Plateau. As important constituents of aerosols, organic acids have been recognized as unique fingerprints to identify the atmospheric process. Here we measured dicarboxylic acids and related compounds in aerosols on the northern slope of Mt. Everest (Qomolangma, 4276 m a.s.l.). Strong positive correlations were observed for dicarboxylic acids with biomass burning tracers, levoglucosan and K(+), demonstrating that this area was evidently affected by biomass burning. The seasonal variation pattern of dicarboxylic acids is consistent with OC and EC, being characterized by a pronounced maximum in the pre-monsoon season. Molecular distributions of dicarboxylic acids and related compounds (malonic acid/succinic acid, maleic acid/fumaric acid) further support this finding. We suggest that the local meteorological conditions and regional atmospheric flow process could facilitate the penetration of the carbonaceous aerosols from South Asia throughout the Himalayas. With the consideration of the darkening force of carbonaceous aerosols, our finding has important implication for this climate-sensitive area, where the glacier melting supplies water for billions of people downstream.
authors: 1] Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China [2] Institute of Low Temperature Science, Hokkaido University, Sapporo. 060-0819, Japan [3] CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China.
authors: Zhiyuan
authors: Z
authors: Cong
authors: Institute of Low Temperature Science, Hokkaido University, Sapporo. 060-0819, Japan.
authors: Kimitaka
authors: K
authors: Kawamura
authors: 1] CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing 100101, China [2] State Key Laboratory of Cryospheric Sciences, Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China.
authors: Shichang
authors: S
authors: Kang
authors: LAPC, Institute of Atmospheric Physics, CAS, Beijing 100029, China.
authors: Pingqing
authors: P
authors: Fu
mesh_terms: D000143:Acids; D000393:Air Pollutants; D001208:Asia; D001272:Atmosphere / Q000737:chemistry*; D018533:Biomass; D005390:Fires; D006801:Humans; D009930:Organic Chemicals
chemical_list: D000143:Acids; D000393:Air Pollutants; D009930:Organic Chemicals