Characteristics of Asian aerosol transport simulated with a regional‐scale chemical transport model during the ACE‐Asia observation
Characteristics of Asian aerosol transport simulated with a regional‐scale chemical transport model during the ACE‐Asia observation
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DOI：
10.1029/2003jd003997
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发表时间：
2004-10
影响因子：
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通讯作者：
S. Satake;I. Uno;T. Takemura;G. Carmichael;Youhua Tang;D. Streets;N. Sugimoto;A. Shimizu;M. Uematsu;Jin-Seok Han;S. Ohta
中科院分区：
文献类型：
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作者：
S. Satake;I. Uno;T. Takemura;G. Carmichael;Youhua Tang;D. Streets;N. Sugimoto;A. Shimizu;M. Uematsu;Jin-Seok Han;S. Ohta
[1]利用CFORS化学输送模式和一个区域气象模式对ACE-亚洲密集观测期间（2001年春季）对流层气溶胶（沙尘、硫酸盐、碳质气溶胶和海盐）的输送和光学厚度进行了模拟。利用地面监测站（PM10、硫酸盐和总含碳气溶胶）、米氏激光雷达和卫星观测数据对模拟气溶胶场进行了深入研究。结果表明，CFORS气溶胶场与观测结果一致，并再现了许多观测特征，包括与大陆外流有关的几个高浓度水平，气溶胶垂直廓线以及沙尘和硫酸盐输送之间的强相关性。我们发现存在的纬度梯度的气溶胶浓度从这些比较。两个月（3月和4月）平均气溶胶浓度场和AOT场更清楚地显示了这种纬向梯度，并表明沙尘主要分布在30°N ~ 45°N之间，而硫酸盐和碳质场则主要占主导地位，其主要源区在中国中部和东南亚至日本北方（25°N ~ 45°N之间）。还进行了气溶胶水平通量的分析。结果表明，这些分布与春季风场特征密切相关，并且每种气溶胶都有如下输送路径：主要的沙尘流是沿沿着北纬45°向东，位于自由大气中;边界层内硫酸盐和碳质气溶胶在华中地区具有顺时针辐散流型，在北方纬度产生与人为排放相关的强外流，并在南方纬度限制大陆外流;高层（2-6 km）的碳质气溶胶有另一条输送路径，即从泰国和老挝沿沿着约30°N输送。对流层气溶胶的区域预算表明，总排放量为105 Tg的灰尘，8.3 Tg-SO2的硫（73%来自人类活动和27%来自火山活动），和3.07 Tg的碳质气溶胶。干沉降、重力沉降和向北流出的沙尘分别占总排放量的33%、27%和14%。硫的湿沉降、向东流出和干沉降分别占33%、27%和21%。对于含碳气溶胶，向东流出的比例最高（49%），其次是干沉降（16%）和向北流出（14%）。
[1] The transport and optical thickness of tropospheric aerosols (dust, sulfate, carbonaceous aerosols, and sea salt) during the ACE-Asia intensive observation period (spring 2001) were simulated using a CFORS chemical transport model coupled with a regional meteorological model. Simulated aerosol fields were examined intensively with surface monitoring stations (PM10, sulfate, and total carbonaceous aerosol), Mie Lidar, and satellite observation data. It was shown that CFORS aerosol fields agree with observations and reproduced many observed characteristics including the several high concentration levels associated with the continental outflow, aerosol vertical profiles and strong correlation between dust and sulfate transports. We found the presence of the latitudinal gradient of aerosol concentrations from these comparisons. The two-month (March and April) averaged aerosol concentration and AOT fields show this latitudinal gradient more clearly, and indicated that the main dust field is located between 30°N and 45°N, while sulfate and carbonaceous field are mainly dominant from their main sources in central China and Southeast Asia to northern Japan (between 25°N and 45°N). Analyses of aerosol horizontal fluxes were also performed. We found that these distributions are closely related to characteristics of wind field of springtime and that each aerosol has the following transport route; the main dust flow is eastward along the 45°N parallel and is located in the free atmosphere; sulfate and carbonaceous aerosols within the boundary layer has a clockwise and divergent flow pattern over central China, which produce the strong outflow associated with anthropogenic emissions at northern latitudes and constrain the continental outflow at the southern latitude; and carbonaceous aerosols at the upper level (2–6 km) have another transport pathway that is along about 30°N from Thailand and Laos. Regional budgets of tropospheric aerosols showed that total emissions were 105 Tg for dust, 8.3 Tg-SO2 for sulfur (73% from human activities and 27% from volcanic activities), and 3.07 Tg for carbonaceous aerosols. Dry deposition, gravitational settling, and northward outflow of dust accounted for 33%, 27%, and 14% of total emissions, respectively. Wet deposition, eastward outflow, and dry deposition of sulfur accounted for 33%, 27%, and 21%, respectively. Regarding carbonaceous aerosols, the outflow to the east has the highest fraction (49%), followed by dry deposition (16%) and the outflow to the north (14%).