Air Pollution, Aerosols and Clouds in the Climate System

The large-scale anthropogenic emissions have been increasingly affecting the air quality as well as regional and global climate by altering Earth’s surface temperature and precipitation patterns. These pollutants are removed from the atmosphere via wet and dry deposition, which in turn may adversely affect the terrestrial and aquatic environments, ranging from acidification of soils and inland waters to the damage of buildings and monuments. The regional precipitation chemistry provides the simplest way to assess the influence of human activities on the composition of the atmosphere, and to improve knowledge of physico-chemical processes related to the atmospheric transport and deposition of pollutants. The chemical composition of an individual precipitation event is dictated by ‘in-cloud’ and ‘below-cloud’ scavenging of atmospheric aerosols and gaseous species derived from natural and anthropogenic sources. Wet and dry deposition also provides information on the exchange of chemical c...

In most climate and radiative transfer models, optical properties of aerosols are modeled using spherical shape assumptions. This assumption is based on sound scientific reasoning. All liquid aerosols have spherical shape because of surface tension. Solid aerosols, which are water soluble also eventually absorbs water vapor from atmosphere and transform themselves into spherical shape. However, dust aerosols are neither liquid nor water soluble. Soot aerosols also fall in this category. Hence, they may not necessarily have spherical shape. This requires that we should examine the validity of spherical shape assumption, particularly for these two types of aerosols. There are two aspects to look at for importance of spherical shape assumption. One is relative magnitude of non-spherical aerosol number concentration. If there are not quite large number of non-spherical particles in the atmosphere, then we need not worry about it. Li and Osada (2007) have shown using model study that dust ...

Recently I received quite a good number of conference related notifications. Many of reader of this blog may be participating it and they shouldn't miss the dead-line so I am listing them below. If you know conference that is not listed below but related to theme of this blog please let us know. 15th National Space Science Symposium, India (NSSS-2008) National Space Science Symposium is one the largest gathering of space scientist in India. It covers wide variety of subjects including remote sensing of atmosphere and climate change study. The next NSSS is going to be held at Radio Astronomy Centre (NCRA-TIFR) in Ooty between 26 and 29 February 2008. Ooty is one of the famous hill-station in India. Last date to submit abstract Dec 7, 2007. Broad subject areas covered in this conference Space- and ground-based astronomy and astrophysics, planetary science / exploration Solar radiation and its interaction with earth's near and distant environment Magnetosphere, ionosphere, therm...