Air Pollution, Aerosols and Clouds in the Climate System

The DAN DAVID PRIZE annually awards 3 prizes of US$ 1 million each for achievements having an outstanding scientific, technological, cultural or social impact on our world. Each year fields are chosen within the three Time Dimensions - Past, Present and Future. Another interesting fact about Dan David Prize is that recipients donate 10% of their prize money to graduate students in their respective field. The 2007 Dan David Prize honors Dr. James Hansen for his significant contributions in the field of "Quest for Energy". He will be sharing the award with Sarah Kurtz and Jerry Olson. James Hansen is a towering figure in atmospheric aerosol research. His paper with Lacis in Nature ( doi:10.1038/346713a0 ) has been used by many to show the importance of atmospheric aerosols in earth's radiation budget. I was so impressed by his paper with Menon, Nazarenko and Luo in Science ( doi:10.1126/science.1075159 ) about climatic effect of black carbon in China and India that I dec...

This paper by Dubovik et al., appeared online in Atmos. Chem. Phys. Discuss. The abstract read as "Knowledge of the global distribution of tropospheric aerosols is important for studying the effects of aerosols on global climate. Chemical transport models rely on archived meteorological fields, accounting for aerosol sources, transport and removal processes can simulate the global distribution of atmospheric aerosols. However, the accuracy of global aerosol modeling is limited. Uncertainty in location and strength of aerosol emission sources is a major factor in limiting modeling accuracy. This paper describes an effort to develop an algorithm for retrieving global sources of aerosol from satellite observations by inverting the GOCART aerosol transport model. To optimize inversion algorithm performance, the inversion was formulated as a generalized multi-term least-squares-type fitting. This concept uses the principles of statistical optimization and unites diverse retrieval techn...

I ran into this article a while ago on EOS transactions (Vol 88, Number 11, 13 March 2007) and it made me pause and think on the message in the article. I thought it was something worth paying attention to and hence decided to post it here for us to contribute to the thought. The purpose of the article was to inform the scientific community of the popularity of Wikipedia and to urge the experts in the community to take a look at the Wikipedia entry for one's area of expertise. The author raises concerns because of the fact that Wikipedia articles are encyclopedic by nature and so provide students with an apparently complete source of material for use in reports and research projects. The question then is: "how good is Wikipedia" in terms of completeness and accuracy? Are students learning the right things? To make Wikipedia as current and updated as possible in terms of information, it allows Anyone with internet connection to write an article about any topic or edit any ...

People started quantifying the role of aerosol chemistry on radiative forcing. There is a nice study by Sussana Bauer from NASA about the effects of heterogeneous reactions among sulfate, nitrate and mineral dust aerosols on radiative forcing. Their modelling study (on global scale) suggest that the combined anthropogenic forcing of dust, nitrate and sulfate is -0.1 W/m2; however, excluding heterogeneous interactions leads to a 3 times larger negative forcing. Full abstract: Coating of mineral dust particles by air pollutants leads to core-mantle particles. These composite aerosols could interact differently with atmospheric radiation than the uncoated dust. In our simplified radiative calculations we assumed that a spherical dust core is covered uniformly by a liquid refractive material, such as sulfate or nitrate. Theoretical calculations of optical properties of such particles show that the single scattering albedo and the asymmetry parameter of core-mantle aerosols only differ sign...