Quantifying contributions of natural and anthropogenic dust emission from different climatic regions

摘要

To quantitatively estimate the divergences in the natural and anthropogenic dust emission fluxes among different climatic regions, the total dust emissions at the global scale from 2007 to 2010 were simulated in this study. Despite the widely scattered anthropogenic dust distribution, the total area of potential anthropogenic dust sources was found slightly higher than that of natural dust sources. The anthropogenic dust distribution area was 1.61 × 107 km2in January and 1.54 × 107 km2in July, respectively. The natural dust sources contributed 81.0% of the global dust emissions and the anthropogenic contributed 19.0% of the residual. The natural and anthropogenic dust emission flux was 6.34 ± 0.31 μg m−2 s−1and 1.01 ± 0.07 μg m−2 s−1, respectively. Especially, natural and anthropogenic dust emissions situated in different climatic regions. Natural dust emissions mainly located in hyper-arid and arid regions such as the Sahara, Arabian and Taklimakan Desert where dust emission fluxes range from 1 to 50 μg m−2 s−1, accounted for 97.3% of natural dust emissions at the global scale. While anthropogenic dust emissions concentrate in semi-arid, sub-humid and humid regions and generally fluctuated between 0.1 and 10 μg m−2 s−1. In addition, natural and anthropogenic dust proportions in semi-arid regions were the most complicated due to the complex land cover types, including grasslands, urban areas, croplands and open shrub lands, resulting in 42.99% of the anthropogenic dust emissions in semi-arid regions. The complex interplay of natural and anthropogenic dust emissions contributing to the total dust loadings may be a crucial factor enhanced the warming over semi-arid regions. This study provided confidence for the further investigation of the climatic impacts of natural and anthropogenic dust in different climatic regions under the background of global warming, especially the strengthening warming in semi-arid regions.