Modeling mineral dust emissions from Chinese and Mongolian deserts
Modeling mineral dust emissions from Chinese and Mongolian deserts
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DOI：
10.1016/j.gloplacha.2006.02.012
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发表时间：
2006-07
影响因子：
3.9
通讯作者：
B. Laurent;B. Marticorena;G. Bergametti;F. Mei
中科院分区：
文献类型：
--
作者：
B. Laurent;B. Marticorena;G. Bergametti;F. Mei
本研究调查了1996年至2001年东亚沙漠上空矿物粉尘排放的频率和强度。采用物理降尘方案模拟了35.5°N ~ 47°N、73°E ~ 125°E范围内的矿物尘排放。沙尘排放模型所需的输入参数是：（1）地表特征数据，包括空气动力学粗糙度、土壤干粒度分布和质地;（2）气象地表数据，主要是风速、土壤湿度和积雪。这些表面特征和气象数据可以评估的方式进行了描述和讨论。考虑了土壤湿度和积雪的影响，定量分析了它们对模拟扬尘的影响。模拟每天再现气象站记录的和/或各种研究中描述的1998年4月和2001年春季严重事件的位置和强度。基于6年的模拟，确定了主要的沙尘源区，并量化了它们对总沙尘排放量的相对贡献。沙尘暴频次的季节变化具有很好的再现性，春季为最大值。模拟结果表明，塔克拉玛干沙漠春末和夏季的大气污染物排放主要受大气污染物排放的控制，而中国北方沙漠冬季的大气污染物排放主要受大气污染物排放的控制。塔克拉玛干沙漠似乎是最频繁和最稳定的沙尘排放源在研究期间。另一方面，在戈壁沙漠中，仅模拟了少数沙尘排放事件，但每次事件期间的沙尘排放量一般都很大。在中国北方沙漠地区，沙尘暴频繁发生，且强度多变。这些结果表明，排放的灰尘（在1亿吨年-1和4.6亿吨年-1之间）的重要的年度和年际变化，主要由发生在戈壁沙漠和北方沙漠的严重事件控制。
The present study investigates the frequency and intensity of mineral dust emissions over the deserts of eastern Asia from 1996 to 2001. Mineral dust emissions are simulated using a physical dust emission scheme over a region extending from 35.5°N to 47°N and from 73°E to 125°E. The input parameters required by the dust emission model are (1) surface features data including aerodynamic roughness length, soil dry size distribution and texture; and (2) meteorological surface data, mainly wind speed, soil moisture and snow cover. The way by which these surface features and meteorological data can be assessed is described and discussed. The influence of soil moisture and snow cover is taken into account and their effects on simulated dust emission are quantified. The simulations reproduce on a daily basis the location and intensity of the severe events of April 1998 and spring 2001 as recorded by the meteorological stations and/or described in various studies. Based on 6 yr of simulations, the main dust source regions are identified and their relative contributions to the total dust emissions are quantified. The seasonal cycle of the dust storms frequency is well reproduced with a maximum in spring. The simulations suggest that it is mainly controlled by the emissions occurring in the Taklimakan desert in latter spring and in summer, and by those occurring in the northern deserts of China in winter. The Taklimakan desert appears to be the most frequent and steady source of dust emissions during the studied period. On the other hand, in the Gobi desert, only a few dust emission events are simulated, but the dust amount emitted during each event is generally very large. In the northern deserts of China, dust emissions are frequent and their intensity is variable. These results show an important annual and inter-annual variability of the emitted dust (between 100 Mt yr−1and 460 Mt yr−1), mainly controlled by the occurrence of severe events in the Gobi desert and in the northern deserts of China.