Aerosol climatology over South Africa based on 10 years of Multiangle Imaging Spectroradiometer (MISR) data

M. Tesfaye, V. Sivakumar, J. Botai, G. Mengistu Tsidu

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

In this paper, we present a detailed study of the spatial and seasonal aerosol climatology over South Africa (SA), based on Multiangle Imaging Spectroradiometer (MISR) data. We have used 10 years (2000-2009) of MISR monthly mean aerosol extinction (τext), absorption (τa) optical depths at 558 nm, Angstrom exponents in visible (VIS; 446-672 nm) and near-infrared (NIR; 672-866 nm) spectral bands, and the extracted spectral curvature. The study has shown that, in terms of aerosol load level spatial variation, SA can be classified into three parts: the upper, central, and lower, which illustrate high, medium, and low aerosol loadings, respectively. The results for the three parts of SA are presented in detail. The prevailing sources of aerosols are different in each part of SA. The lower part is dominated by the air mass transport from the surrounding marine environment and other SA or neighboring regions, while the central and upper parts are loaded through wind-ablated mineral dust and local anthropogenic activities. During the biomass burning seasons (July-September), the central part of SA is more affected than the rest of SA by the biomass-burning aerosols (based on τa, ∼20% higher than the rest of SA). In alignment with the observed higher values of τext, aerosol size distributions were found to be highly variable in the upper part of SA, which is due to the high population and the industrial/mining/agricultural activities in this area.

Original languageEnglish
Article numberD20216
JournalJournal of Geophysical Research Atmospheres
Volume116
Issue number20
DOIs
Publication statusPublished - Jan 1 2011

Fingerprint

MISR
spectroradiometers
Climatology
climatology
Republic of South Africa
aerosols
Aerosols
South Africa
image analysis
aerosol
Imaging techniques
biomass burning
Biomass
extinction
burning season
Africa
marine environments
Minerals
Dust
air masses

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

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abstract = "In this paper, we present a detailed study of the spatial and seasonal aerosol climatology over South Africa (SA), based on Multiangle Imaging Spectroradiometer (MISR) data. We have used 10 years (2000-2009) of MISR monthly mean aerosol extinction (τext), absorption (τa) optical depths at 558 nm, Angstrom exponents in visible (VIS; 446-672 nm) and near-infrared (NIR; 672-866 nm) spectral bands, and the extracted spectral curvature. The study has shown that, in terms of aerosol load level spatial variation, SA can be classified into three parts: the upper, central, and lower, which illustrate high, medium, and low aerosol loadings, respectively. The results for the three parts of SA are presented in detail. The prevailing sources of aerosols are different in each part of SA. The lower part is dominated by the air mass transport from the surrounding marine environment and other SA or neighboring regions, while the central and upper parts are loaded through wind-ablated mineral dust and local anthropogenic activities. During the biomass burning seasons (July-September), the central part of SA is more affected than the rest of SA by the biomass-burning aerosols (based on τa, ∼20{\%} higher than the rest of SA). In alignment with the observed higher values of τext, aerosol size distributions were found to be highly variable in the upper part of SA, which is due to the high population and the industrial/mining/agricultural activities in this area.",
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Aerosol climatology over South Africa based on 10 years of Multiangle Imaging Spectroradiometer (MISR) data. / Tesfaye, M.; Sivakumar, V.; Botai, J.; Mengistu Tsidu, G.

In: Journal of Geophysical Research Atmospheres, Vol. 116, No. 20, D20216, 01.01.2011.

Research output: Contribution to journalArticle

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