Climate effects of dust aerosols over East Asian arid and semiarid regions

Jianping Huang, Tianhe Wang, Wencai Wang, Zhanqing Li, Hongru Yan
2014 Journal of Geophysical Research - Atmospheres  
East Asia is a major dust source in the world. Mineral dusts in the atmosphere and their interactions with clouds and precipitation have great impacts on regional climate in Asia, where there are large arid and semiarid regions. In this review paper, we summarize the typical transport paths of East Asian dust, which affect regional and global climates, and discuss numerous effects of dust aerosols on clouds and precipitation primarily over East Asian arid and semiarid regions. We hope to
more » ... a benchmark of our present understanding of these issues. Compared with the aerosols of Saharan dust, those of East Asian dust are more absorptive of solar radiation, and its direct radiative forcing at the top of atmosphere is nearly positive or nil. It means that aerosols of East Asian dust can influence the cloud properties not only by acting as cloud condensation nuclei and ice nuclei (via first indirect effect, second indirect effect, and invigoration effect) but also through changing the relative humidity and stability of the atmosphere (via semidirect effect). Converting visible light to thermal energy, dust aerosols can burn clouds to produce a warming effect on climate, which is opposite to the first and second indirect effects of aerosols. The net dust aerosol radiative effects are still highly unclear. In addition, dust can inhibit or enhance precipitation under certain conditions, thus impacting the hydrological cycle. Over Asian arid and semiarid regions, the positive feedback loop in the aerosol-cloud-precipitation interaction may aggravate drought in its inner land. Dust particles are produced by disintegration of aggregates following creeping and saltation of larger soil particles over deserts and other arid/semiarid surfaces [Kok, 2011; Zhao et al., 2006] . Mineral aerosol may be composed of iron oxides (e.g., hematite and goethite), carbonates (e.g., calcite and dolomite), quartz, and clays (e.g., kaolinite, illite, and montmorillonite) [Chou et al., 2008; Coz et al., 2009; Lafon et al., 2006; Twohy et al., 2009] . The rising number of dust storms is due to increasing desertification, which is fed, in turn, by dust events that exacerbate drought conditions over semiarid areas [Han et al., 2008; Wang et al., 2008; J.-P. Huang et al., 2010]. HUANG ET AL. Key Points: • East Asian dust affects regional and global climate by typical transport paths • East Asian dust aerosols are more absorptive than those from Saharan Desert • Dust-cloud-precipitation interaction over arid regions may aggravate drought (2014) , Climate effects of dust aerosols over East Asian arid and semiarid regions,
doi:10.1002/2014jd021796 fatcat:gspcjtpm6vgqjms7isn2z6476y