Diurnal variability of dust aerosol optical thickness and Angström exponent over dust source regions in China
Diurnal variability of dust aerosol optical thickness and Angström exponent over dust source regions in China
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DOI：
10.1029/2004gl019580
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发表时间：
2004-04
影响因子：
5.2
通讯作者：
Jun Wang;X. Xia;Pucai C. Wang;S. Christopher
中科院分区：
文献类型：
--
作者：
Jun Wang;X. Xia;Pucai C. Wang;S. Christopher
使用22个月在中国塔克拉玛干和戈壁沙尘源区（敦煌，40.09°N，94.41°E）附近收集的太阳光度计气溶胶光学厚度（AOT）数据；我们研究了粉尘气溶胶特性的日间和季节变化。大多数沙尘事件发生在春季至初夏期间，AOT 的季节性日变化超过 ±10%，Angström 指数的日变化超过 ±30%，下午晚些时候 AOT 较大，Angström 指数值较小。与最近的研究相比，这些值要大得多，最近的研究报告称，在灰尘是 AOT 的主要贡献者的各个 AERONET 站点上，灰尘 AOT 的日变化要小得多 (±5%)。这些差异主要是由于地理位置和气象条件造成的，沙尘源区域或附近气溶胶特性的如此大的日变化可能足以在区域辐射强迫、空气质量和数值模拟研究中考虑。
Using 22 months of Sunphotometer Aerosol Optical Thickness (AOT) data collected near the Taklamakan and Gobi dust source regions (Dunhuang, 40.09°N, 94.41°E) in China; we examine the diurnal and seasonal change of dust aerosol properties. Most dust events are during the spring through early summer months with a season‐invariant diurnal change of more than ±10% for AOT and ±30% for Angström exponent, with larger AOT and smaller Angström exponent values late in the afternoon. These values are much larger when compared to recent studies that have reported a much smaller (±5%) diurnal variability of dust AOT over various AERONET sites where dust is a major contributor to AOT. The differences are largely due to the geographical locations and meteorological conditions and such large diurnal changes of aerosol properties at or near dust source regions may be significant enough for consideration in regional radiative forcing, air quality and numerical modeling studies.