The Arctic and northern subpolar regions are critical for climate change. Ice-albedo feedback amplifies warming in the Arctic, and fluctuations of regional fresh water inflow to the Arctic Ocean modulate the deep ocean circulation and thus exert a strong global influence. By comparing observations to simulations from 22 coupled climate models, the researchers find influence from anthropogenic greenhouse gases and sulfate aerosols in the space-time pattern of precipitation change over high latitude land areas during the second half of the 20th century.

If you do like to be beside the seaside, it might be best to avoid beaches near major ports. The mix of sea salt, ship fumes and city smoke leads to a chemical reaction that encourages the formation of ozone smog, adding to the pollution that forms in cities. James Roberts from the National Oceanic and Atmospheric Administration Earth System Research Laboratory in Boulder, Colorado, and his colleagues have developed a mass spectrometer that can detect nitryl chloride (NO2Cl) - a chemical that aids the formation of ozone.

Black carbon in soot is the dominant absorber of visible solar radiation in the atmosphere. Anthropogenic sources of black carbon, although distributed globally, are most concentrated in the tropics where solar irradiance is highest. Black carbon is often transported over long distances, mixing with other aerosols along the way. The aerosol mix can form transcontinental plumes of atmospheric brown clouds, with vertical extents of 3 to 5 km.

Climate change authorities long ago tagged carbon dioxide public enemy number one. Now, there may be a new number two: tiny particles of black carbon, or soot. According to a new analysis reported online in Nature Geoscience, climate scientists are concluding that reports such as last November's assessment by the Intergovernmental Panel on Climate Change (IPCC) may seriously underestimate black carbon's role in global warming.

Abstract Black carbon in soot is the dominant absorber of visible solar radiation in the atmosphere. Anthropogenic sources of black carbon, although distributed globally, are most concentrated in the tropics where solar irradiance is highest. Black carbon is often transported over long distances, mixing with other aerosols along the way. The aerosol mix can form transcontinental plumes of atmospheric brown clouds, with vertical extents of 3 to 5 km.

Residue burning practice is followed in major Indian states of Uttar Pradesh and Punjab. Agricultural residue burning in the fields and used otherwise for rural domestic needs is responsible for a large number of toxic emissions, which are a health hazard.

Harvesting a crop generates a huge amount of crop residue. Uttar Pradesh tops the list of the Crop Residue Producing States followed by Punjab, Madhya Pradesh and so on. A large part of this crop residue is burnt in the open fields since the farmers do not have any worthwhile use of this waste. Burning of residues give rise to emissions of aerosols, major gases and trace gases.

Aerosols play an integral role in climate by directly scattering or absorbing solar radiation, and indirectly these particles serve as condensation and ice nucleic in clouds. Ice formation in tropospheric clouds is required for snow and most rainfall.

Ariyalur, the land of fossils, is found to be embedded with rich limestone deposits. Hence around 9 cement factories have been established in and around Ariyalur. This becomes one of the source of air pollution in this area.