Yun Qian, Ruby Leung and colleagues of Pacific Northwest National Laboratory, Richland, Washington, USA analyzed observation data from 500+ meteorological stations in all regions of China.
The amount of the clear days in the period 1954 to 2001 have increased per decade by 0,6%, days with covered sky decreased against it by 0,78 % per decade. At the same time also the sun exposure per decade decreased by 3,1 Watts per square meter.
The researchers speculate that increased air pollution and rising concentration of aerosols (particles, mainly soot and sulfur) results to less solar radiation reaching the surface.
And haze has impact on water cycle, persistency of clouds and precipitation.
Simulations cited in the resarchers paper calculate that up to 50 percent of the surface warming in South Asia has been masked by haze. If emission trends continue, the subcontinent will face twice as many droughts in future.
