类腐殖质气溶胶(HULIS)是大气有机气溶胶的主要组成部分,对云凝结核的形成和气溶胶吸湿性增长至起着重要作用,但是HULIS的性质和来源在很大程度上仍是未知的。本文使用固相萃取法获得了2008年7月至2009年8月间西安PM2.5中的HULIS,并采用热光法获得HULIS的碳含量(HULIS-C)。HULIS-C年均质量浓度为3.1±3.0μg C m-3。HULIS含量冬季最高(6.2μg C m-3),秋季次之(3.3μg C m-3)、夏季(1.5μg C m-3)和春季较低(1.2μg C m-3)。冬季高浓度的主要原因是冬季能源消耗量大,比如燃煤和生物质燃烧;而春夏季低浓度主要是由于较少的能源消耗和较丰富的降水。HULIS是水溶性有机碳(WSOC)的重要组分,占WSOC的34.5%,表明其是影响WSOC吸湿性的重要组分;相关性分析表明,HULIS与左旋葡聚糖(r=0.84)和K+(r=0.81)呈显著相关,说明HULIS主要来源于生物质燃烧;此外,HULIS与二次有机碳(SOC)相关性良好(r=0.83),表明HULIS同时有二次来源。
Biomass burning in the Indochina Peninsula(Indochina) is one of the important ozone sources in the low troposphere over East Asia in springtime. Moderate Resolution Imaging Spectroradiometer(MODIS) data show that 20,0...
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Biomass burning in the Indochina Peninsula(Indochina) is one of the important ozone sources in the low troposphere over East Asia in springtime. Moderate Resolution Imaging Spectroradiometer(MODIS) data show that 20,000 or more active fire detections occurred annually in spring only from 2000 to 2011. In this study, WRF-Chem model was employed to evaluate the biomass burning products transport from Indochina during the episodes between 15 and 19 March, 2008. Hourly Data at background Liulin mountain station(2862 m elevation) shows that CO, O3 and PM10 are ranging about 200-300 ppb, 30-60 ppb and 50-80 ug/m3, respectively. It was estimated that the concentrations of those species are about factor of 2-3 higher than other seasons during study period. Simulation results demonstrate that the leeside troughs over Indochina play a dominant role in the uplift of the air pollutants below 3 km. Furthermore, the impact of biomass burning from Indochina on downward shortwave flux could as high as around 20- 30 Wm-2 in northern Taiwan during study period.
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