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Transboundary transport and deposition of Hg emission from springtime biomass burning in the Indo‐China Peninsula
Author(s) -
Wang Xun,
Zhang Hui,
Lin CheJen,
Fu Xuewu,
Zhang Yiping,
Feng Xinbin
Publication year - 2015
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2015jd023525
Subject(s) - environmental science , atmospheric sciences , biomass burning , deposition (geology) , peninsula , particulates , environmental chemistry , mercury (programming language) , biomass (ecology) , aerosol , chemistry , meteorology , geology , geography , oceanography , paleontology , archaeology , organic chemistry , sediment , computer science , programming language
Biomass burning from the Indo‐China Peninsula region is an important source of atmospheric mercury (Hg). We isolated 18 unique transport events over 2 years using observations of Hg and CO at a high‐altitude background site in southwestern China (Mount Ailao Observatory Station) to assess the transport and impact of Hg emissions from biomass burning. The quantity of Hg emission and the source regions were determined using ΔTGM/ΔCO slopes coupled with backward trajectory analysis and CO emission inventories. The slopes of ΔTGM/ΔCO appeared to be a useful chemical indicator for source identification. Industrial emission sources exhibited slopes in the range of 5.1–61.0 × 10 −7 (parts per trillion by volume, pptv/pptv), in contrast to a slope of 2.0–6.0 × 10 −7 for typical biomass burning. Transboundary transport of Hg from biomass burning led to episodically elevated atmospheric Hg concentrations during springtime. Hg emissions from biomass burning in the Indo‐China Peninsula region from 2001 to 2008 were estimated to be 11.4 ± 2.1 Mg yr −1 , equivalent to 40% of annual anthropogenic emissions in the region. In addition, Hg emissions from biomass burning contained a substantial fraction of particulate bound Hg (PBM). Assuming that PBM readily deposits locally (within 50 km), the local Hg deposition caused by the PBM was estimated to be 2.2 ± 0.4 Mg yr −1 , up to 1 order of magnitude higher than the PBM deposition caused by anthropogenic emissions during springtime in the region. The strong springtime emissions potentially pose a threat to the ecosystems of the Indo‐China Peninsula and southwest China.