Impacts of lindane usage in the Canadian prairies on the Great Lakes ecosystem. 1. Coupled atmospheric transport model and modeled concentrations in air and soil
Impacts of lindane usage in the Canadian prairies on the Great Lakes ecosystem. 1. Coupled atmospheric transport model and modeled concentrations in air and soil
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DOI：
10.1021/es034160x
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发表时间：
2003-09-01
影响因子：
11.4
通讯作者：
Li, YF
中科院分区：
文献类型：
--
作者：
Ma, JM;Daggupaty, S;Li, YF
为了调查加拿大大草原对五大湖地区使用γ-六氯环己烷（γ-HCH或林丹）的影响，开发了一个大气传输、土壤-空气、水-空气交换耦合模型。空气和土壤中γ-六氯环己烷的命运取决于耦合模型描述的大气动力学以及物理和化学过程。这些过程包括大气中的迁移和湍流扩散、干和湿沉降、空气-水和土壤-空气界面的交换以及从土壤中去除的过程，如扩散、沥滤和降解。从1998年5月1日至1999年4月30日，从春季应用林芝开始，进行了数值试验。耦合模型执行两个线性排放（使用）清单中的模型域。第一种方案包含加拿大所有已知的新排放源--98%是在大草原上使用;第二种方案排除了来自安大略和魁北克的排放源。该模型表明，在没有从过去的应用林丹，使用林丹在安大略和魁北克在这些地区的空气浓度的影响可以忽略不计，在五大湖生态系统的林丹预算主要是由于应用林丹在加拿大草原省份的油菜田。模型预测的空气浓度和季节趋势与在大气沉积物综合网络下运行的几个背景站点在同一时期的测量数据吻合得很好。研究表明，空气温度对γ-六氯环己烷的表面-空气交换动力学起着关键作用。未来的论文将根据这些经过验证的模型结果评估五大湖的负荷。
A coupled atmospheric transport, soil-air, water-air exchange model was developed to investigate the impacts of gamma-hexachlorocyclohexane (gamma-HCH or lindane) usage in the Canadian prairies over the Great Lakes region. The fate of gamma-HCH in air and soil is governed by atmospheric dynamics and physical and chemical processes that are described by the coupled model. These processes include transport and turbulent diffusion in the atmosphere, dry and wet deposition, exchange at the interfacial boundaries of air-water and soil-air, and removal processes from the soil such as diffusion, leaching, and degradation. Numerical experiments were conducted for the period of May 1, 1998-April 30,1999, starting with application of lindane in the spring. The coupled model was executed with two lindane emission (usage) inventories in the model domain. The first scenario contained all known fresh emission sources in Canada-98% was usage in the prairies; the second excluded emission sources from Ontario and Quebec. The model showed that, in the absence of the reemission from past application of lindane, usage of lindane in Ontario and Quebec has a negligible impact on air concentrations in these regions and that the lindane budget in the Great Lakes ecosystem is mostly attributed to applications of lindane in the canola fields in Canadian prairie provinces. Model-predicted air concentrations and seasonal trends agreed well with measured data over the same time period for several background sites operated under the Integrated Atmospheric Deposition Network. Air temperature was shown to play a key role on surface-air exchange dynamics of gamma-HCH. A future paper will assess loadings to the Great Lakes based on these validated model results.