Abstract:Based on a 10-year (1995~2004) simulation of dust emissions and dry and wet depositions with the global air quality model system GEM-AQ/EC, the global spatial and temporal variations of the dust aerosol sources and sinks were characterized. Global dust emissions are centered over the major desert regions where the North African deserts are estimated with the largest emission contribution to the global dust aerosol up to 66.6%; the high dust aerosol depositions are concentrated over the desert sources and their immediately downwind areas. Thereby, the net dust aerosol sinks are largely distributed around the desert regions forming a receptor zone with the net sinks of greater than 10t/(km2×a) between 0°N and 60°N from North Africa, Eurasia, west Pacific Ocean, the north Indian Ocean, North America to the Atlantic ocean. In five major deserts of North Africa, Arabian Peninsula, Central Asia, East Asia and Australia, the dust emissions and depositions present the significant seasonal variations, The regional depositions expecting Central Asia experience almost the same seasonal cycle with the emissions; both dust aerosol emissions and depositions oscillate seasonally with the largest amplitudes in East Asia and with the lowest amplitudes in the North Africa. The seasonal dust emissions and depositions peak in summer over Central Asia and the Arabian Peninsula as well as during spring in the other three regions. Over the10 years, the global annual emission is averaged with (1500±94)Mt in a slightly rising trend. The inter-annual variability rate of dust emissions in North Africa is lowest (6.3%), up to 28.3% in East Asia and highest in Australia (45.0%). The dust aerosol depositions over global land decrease at a rate of around 9.9Mt/a, while they increase year to year over the oceans.
刘建慧, 赵天良, 韩永翔, Gong S L, 熊洁. 全球沙尘气溶胶源汇分布及其变化特征的模拟分析[J]. 中国环境科学, 2013, 33(10): 1741-1750.
LIU Jian-Hui, ZHAO Tian-Liang, HAN Yong-Xiang, Gong S L, XIONG Jie. Modeling study on distributions and variations of global dust aerosol sources and sinks. CHINA ENVIRONMENTAL SCIENCECE, 2013, 33(10): 1741-1750.