Particulate Absorption of Solar Radiation: Anthropogenic Aerosols vs. Dust

Joint Program Reprint • Journal Article
Particulate Absorption of Solar Radiation: Anthropogenic Aerosols vs. Dust
Wang, C., G.-R. Jeong and N. Mahowald (2009)
Atmospheric Chemistry and Physics, 9(12): 3935-3945

Reprint 2009-10 [Download]

Abstract/Summary:

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., G.-R. Jeong and N. Mahowald (2009): Particulate Absorption of Solar Radiation: Anthropogenic Aerosols vs. Dust. Atmospheric Chemistry and Physics, 9(12): 3935-3945 (http://www.atmos-chem-phys.net/9/3935/2009/)
  • Joint Program Reprint
  • Journal Article
Particulate Absorption of Solar Radiation: Anthropogenic Aerosols vs. Dust

Wang, C., G.-R. Jeong and N. Mahowald

2009-10
9(12): 3935-3945

Abstract/Summary: 

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.