Trends in sulfate and organic aerosol mass in the Southeast U.S.: Impact on aerosol optical depth and radiative forcing
Trends in sulfate and organic aerosol mass in the Southeast U.S.: Impact on aerosol optical depth and radiative forcing
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DOI：
10.1002/2014gl061669
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发表时间：
2014-11-16
影响因子：
5.2
通讯作者：
Brown, S. S.
中科院分区：
文献类型：
--
作者：
Attwood, A. R.;Washenfelder, R. A.;Brown, S. S.
自20世纪90年代初以来，美国的二氧化硫排放量有所下降，导致美国东南部气溶胶硫酸盐质量下降。S. 1992年至2013年为-4.5（+/- 0.9）% yr（-1）。有机气溶胶质量，在美国东南部的另一个主要气溶胶成分。美国，尽管同时减少了人为前体的排放量，夏季测量在农村亚拉巴马量化气溶胶消光的变化作为气溶胶成分和相对湿度的函数。将这一关系应用于2001年至2013年的成分数据表明，消光率每年减少-1.1（+/- 0.7）%，这可归因于气溶胶硫酸盐/有机物比例变化引起的气溶胶水质量减少。计算的消光减少量与地基和卫星气溶胶光学厚度的区域趋势一致。夏季地面辐射效应的日平均变化为8.0 W m（-2），其中19%归因于气溶胶水的减少。
Emissions of SO2 in the United States have declined since the early 1990s, resulting in a decrease in aerosol sulfate mass in the Southeastern U. S. of -4.5(+/- 0.9)% yr(-1) between 1992 and 2013. Organic aerosol mass, the other major aerosol component in the Southeastern U. S., has decreased more slowly despite concurrent emission reductions in anthropogenic precursors. Summertime measurements in rural Alabama quantify the change in aerosol light extinction as a function of aerosol composition and relative humidity. Application of this relationship to composition data from 2001 to 2013 shows that a -1.1(+/- 0.7)% yr(-1) decrease in extinction can be attributed to decreasing aerosol water mass caused by the change in aerosol sulfate/organic ratio. Calculated reductions in extinction agree with regional trends in ground-based and satellite-derived aerosol optical depth. The diurnally averaged summertime surface radiative effect has changed by 8.0 W m(-2), with 19% attributed to the decrease in aerosol water.