Deducting Polluted Asian Aerosol Chemical and Optical Properties Using Decadal Scale AERONET Measurements and a Mie Model

Aerosols have been identified as one of the largest contributors to the uncertainty in our understanding of a diverse set of issues, including radiation. The air pollution in Asia is pretty severe and complicated, as every region has its own chemical and economic characteristics. Changes occur not only in magnitude, but also in a spatial-temporal sense, as different regions undergo different pathways of development.

A detailed analysis of the decadal AERONET optical measurements reveals important changes in the size, and chemical composition of aerosols throughout most area of Asia. Our analysis of the multi-spectral AERONET AOD, SSA, and size measurements, reveals that aerosols in Asia have at least 4 different characteristics: Biomass Burning, Urbanization, Long Range Transport, and Relatively Clean. Specially, the impact of identifying Long Range Transport is essential, since AERONET stations are fixed in time and space, and have not been previously used to make such a classification.

We then integrate these results with a core-shell MIE model, and determine the rough chemical and optical aerosol characteristics. With a focus on BC, OC, Sulfate, Nitrate, and mixing state, we are able to generate consistent results with various modeling studies and independent measurements. The results conform very well over regions that are known to be heavily polluted, both in terms of urban, biomass burning, and mixed sources, as compared with measurements from the OMI, MOPITT, and MISR satellites.

The ability to identify and to classify mixed regions is hinted at, but will require further modeling studies to further support. However, an initial quick comparison with our group's multi-satellite constrained modeling work on biomass burning over South, South East, and East Asia, shows a decent first order comparison, encouraging us to integrate this more detailed approach into the global CAM5 modeling system in the future.

Aerosols have been identified as one of the largest contributors to the uncertainty in our understanding of a diverse set of issues, including radiation. The air pollution in Asia is pretty severe and complicated, as every region has its own chemical and economic characteristics. Changes occur not only in magnitude, but also in a spatial-temporal sense, as different regions undergo different pathways of development.

A detailed analysis of the decadal AERONET optical measurements reveals important changes in the size, and chemical composition of aerosols throughout most area of Asia. Our analysis of the multi-spectral AERONET AOD, SSA, and size measurements, reveals that aerosols in Asia have at least 4 different characteristics: Biomass Burning, Urbanization, Long Range Transport, and Relatively Clean. Specially, the impact of identifying Long Range Transport is essential, since AERONET stations are fixed in time and space, and have not been previously used to make such a classification.

We then integrate these results with a core-shell MIE model, and determine the rough chemical and optical aerosol characteristics. With a focus on BC, OC, Sulfate, Nitrate, and mixing state, we are able to generate consistent results with various modeling studies and independent measurements. The results conform very well over regions that are known to be heavily polluted, both in terms of urban, biomass burning, and mixed sources, as compared with measurements from the OMI, MOPITT, and MISR satellites.

The ability to identify and to classify mixed regions is hinted at, but will require further modeling studies to further support. However, an initial quick comparison with our group's multi-satellite constrained modeling work on biomass burning over South, South East, and East Asia, shows a decent first order comparison, encouraging us to integrate this more detailed approach into the global CAM5 modeling system in the future.