Sunday, February 24, 2008

Aerosol Radiative Effects over Global Land: A Satellite based Study

GRL published an article on estimation of aerosol radiative effects over global land using purely observations from Terra satellite on February 22, 2008. Although, I am one of the co-author in the paper but I would like to congrats Falguni Patadia, first author of the paper for her research, which is first attempt in certain ways. This paper presents the estimation of top of the atmosphere (TOA) short wave aerosol radiative effects over global land areas for each half degree by half degree grid point. The uniqueness of the study comes from the fact that it is purely observation based study, which does not involve any complex radiative transfer and/or climate model runs. Results of the study are encouraging and matches very well with other purely model or hybrid (model and observations) type of studies. This research used one year worth of satellite observations of TOA fluxes derived from CERES broadband instrument, MODIS high resolution cloud masks and MISR derived aerosol optical thickness data sets to perform the analysis. As we all know that, aerosol impacts in climate change studies in one of the most uncertain component and level of scientific understanding about this component is very low. This study is certainly a good start and will help to understand aerosol effects on earth-atmosphere radiation budget. For more details on the results and methodology, please refer the publication and if you do not have access to the article, we will be happy to share reprints with you.

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Harish Gadhavi said...

Indeed an interesting article. Radiative forcing by aerosol is one of the largest source of uncertainty in climate models. Being able to estimate using satellite based observations is big step forward.

I am very much surprised to see that Australia have quite low aerosol optical depth compare to India, still they have comparable radiative forcing (Fig.1 original article).

Falguni Patadia said...

Thats a good observation Harish! I think this is the interesting part of this paper. There are couple of other regions besides Australia (discussed in paper) that have low AOT values but comparable forcing values and vice-a-versa. In Australia, it is the background/surface that plays a role besides aerosol concentration. The results from this paper agree with the various factors affecting the aerosol radiative forcing such as aerosol concentration, surface conditions, aerosol distribution, aerosol type etc. A combination of these is what we are seeing in the annual globally averaged map.

Dagny said...

Great article. Amazing to see the global reaches of aerosol.

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