Editor's Summary
2 August 2007
The heat is on
By 2001, it was realized that the thick brown haze discovered over the Arabian Sea during the Indian Ocean Experiment (INDOEX: 1997-1999) was a persistent dry-season feature above Southern Asia. A UNEP report in 2002 raised concerns of major climate disruption if the sources of the haze, including biomass burning, were not controlled. NASA's TERRA satellite has since detected similar atmospheric brown clouds (ABCs) elsewhere. Atmospheric solar heating and surface dimming due to ABCs both drive climate change, and to quantify that change we need direct measurements like the two datasets presented this week. First, three stacked, autonomous, unmanned aircraft measured solar heating above the Indian Ocean. Second, the CALIPSO satellite tracked a 3-km-thick haze from the Indian Ocean to the Himalayas. Climate modelling with the data suggests that ABC-induced atmospheric warming resembles that induced by greenhouse gases, a possible explanation for Himalayan glacier retreat.
News and Views: Climate change: Aerosols heat up
Solid particles suspended in the atmosphere have long played second fiddle to greenhouse gases as agents of climate change. A study of atmospheric heating over the Indian Ocean could provoke a rethink.
Peter Pilewskie
doi:10.1038/448541a
Letter: Warming trends in Asia amplified by brown cloud solar absorption
Veerabhadran Ramanathan, Muvva V. Ramana, Gregory Roberts, Dohyeong Kim, Craig Corrigan, Chul Chung & David Winker
doi:10.1038/nature06019
First paragraph | Full Text | PDF (918K) | Supplementary information
