Model Study of Global Mercury Deposition from Biomass Burning
Model Study of Global Mercury Deposition from Biomass Burning
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DOI：
10.1021/acs.est.5b00969
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发表时间：
2015-06-02
影响因子：
11.4
通讯作者：
Pirrone, Nicola
中科院分区：
文献类型：
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作者：
De Simone, Francesco;Cinnirella, Sergio;Pirrone, Nicola
生物质燃烧产生的汞排放尚未得到很好的表征，且每年可能存在显著差异。本研究利用三个近期的生物质燃烧清单（FINNv1.0、GFEDv3.1和GFASv1.0）以及全球汞化学模型ECHMERIT，来研究汞排放的年际变化以及由此产生的汞沉降通量的地理分布和大小。研究考虑了汞/一氧化碳增强比、排放烟羽注入高度、气态零价汞（Hg-(g)(0)）氧化机制和寿命、所选清单以及各自的不确定性等因素的作用。研究发现，总汞沉降的最大不确定性与汞/一氧化碳增强比和所采用的排放清单有关。事实证明，沉降通量分布对排放清单和所选氧化机制比其他所有模型参数化更为敏感。生物质燃烧排放的汞超过75%沉积在世界海洋中，北大西洋预测的通量最高，北太平洋的总沉降量最高。生物质燃烧的净效应是将汞从低纬度地区释放出来，并将其向高纬度地区扩散，最终在高纬度地区沉降。
Mercury emissions from biomass burning are not well characterized and can differ significantly from year to year. This study utilizes three recent biomass burning inventories (FINNv1.0, GFEDv3.1, and GFASv1.0) and the global Hg chemistry model, ECHMERIT, to investigate the annual variation of Hg emissions, and the geographical distribution and magnitude of the resulting Hg deposition fluxes. The roles of the Hg/CO enhancement ratio, the emission plume injection height, the Hg-(g)(0) oxidation mechanism and lifetime, the inventory chosen, and the uncertainties with each were considered. The greatest uncertainties in the total Hg deposition were found to be associated with the Hg/CO enhancement ratio and the emission inventory employed. Deposition flux distributions proved to be more sensitive to the emission inventory and the oxidation mechanism chosen, than all the other model parametrizations. Over 75% of Hg emitted from biomass burning is deposited to the worlds oceans, with the highest fluxes predicted in the North Atlantic and the highest total deposition in the North Pacific. The net effect of biomass burning is to liberate Hg from lower latitudes and disperse it toward higher latitudes where it is eventually deposited.