March 5, 2007
Noting that sulfate and soot emissions have risen significantly in Asia since the 1970s as a result of increased coal burning from rapid industrialization, Renyi Zhang of Texas A&M University and colleagues analyzed cloud measurement data spanning 1984-2005 and found that the rise in pollution generated stronger thunderstorms. Their research showed a 20-50% increase in the formation of deep convective clouds (DCC) between 1984-1994 and 1994-2005.
"We have unambiguously identified a trend of increasing DCC over the north Pacific in winter, and we have demonstrated the link between the intensified Pacific storm track and Asian pollution outflow," the authors write. "Our results suggest that the winter Pacific is highly vulnerable to the aerosol effect because of favorable cloud dynamical and microphysical conditions from the interaction between the storm track and Asian pollution outflow.
Difference between the January distribution of deep convective cloud amounts from International Satellite Cloud Climatology Project (ISCCP) averaged between the periods of 1984–1994 (a) and 1994–2005. Image copyright 2007 by The National Academy of Sciences of the USA
"The intensified Pacific storm track likely has profound implications on climate," they continue. "Intensified storms of the Pacific storm track can significantly alter the cloud albedo and impact the radiative budget over such a large region. The intensified Pacific storm track can also impact the global general circulation... Furthermore, the intensified storm track can transfer efficiently anthropogenic aerosols vertically and northward... [and can] exacerbate warming at higher latitudes."
The authors note that such climate heating in polar regions has been linked to melting sea ice and rising sea levels.
Zhang et. al (2007). Intensification of Pacific storm track linked to Asian pollution. PNAS Early Edition, March 6, 2007.
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keywords: airpollution haze smog pm10 co2 climate change greenhouse effect polluted air aerosols volcanic eruptions sahara storms weather modification fire rainforest extinction habitat destruction