Atmos. Chem. Phys., 9, 3935-3945, 2009
www.atmos-chem-phys.net/9/3935/2009/
doi:10.5194/acp-9-3935-2009
© Author(s) 2009. This work is distributed
under the Creative Commons Attribution 3.0 License.
Particulate absorption of solar radiation: anthropogenic aerosols vs. dust
C. Wang1, G. R. Jeong1, and N. Mahowald2
1Massachusetts Institute of Technology, Cambridge, MA 02139, USA
2Cornell University, Ithaca, NY 14853, USA

Abstract. Particulate solar absorption is a critical factor in determining the value and even sign of the direct radiative forcing of aerosols. The heating to the atmosphere and cooling to the Earth's surface caused by this absorption are hypothesized to have significant climate impacts. We find that anthropogenic aerosols play an important role around the globe in total particulate absorption of solar radiation. The global-average anthropogenic fraction in total aerosol absorbing optical depth exceeds 65% in all seasons. Combining the potentially highest dust absorption with the lowest anthropogenic absorption within our model range, this fraction would still exceed 47% in most seasons except for boreal spring (36%) when dust abundance reaches its peak. Nevertheless, dust aerosol is still a critical absorbing constituent over places including North Africa, the entire tropical Atlantic, and during boreal spring in most part of Eurasian continent. The equality in absorbing solar radiation of dust and anthropogenic aerosols appears to be particularly important over Indian subcontinent and nearby regions as well as North Africa.

Citation: Wang, C., Jeong, G. R., and Mahowald, N.: Particulate absorption of solar radiation: anthropogenic aerosols vs. dust, Atmos. Chem. Phys., 9, 3935-3945, doi:10.5194/acp-9-3935-2009, 2009.
 
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