HR: 1340h
AN: A43D-0123    [Abstracts]
TI: More frequent cloud-free sky and less surface solar radiation in China from 1955-2000
AU: * Qian, Y
EM: yun.qian@pnl.gov
AF: Pacific Northwest National Laboratory, 3200 Q Avenue, Richland, wa 99354 United States
AU: Kaiser, D
EM: d9k@ornl.gov
AF: Oak Ridge National Laboratory, MS-6335, Oak Ridge, tn 37831 United States
AU: Leung, R
EM: ruby.leung@pnl.gov
AF: Pacific Northwest National Laboratory, 3200 Q Avenue, Richland, wa 99354 United States
AU: Xu, M
EM: mingxu@crssa.rutgers.edu
AF: Rutgers University, 14 College Farm Road, New Brunswick, nj 08901 United States
AB: Newly available data from an expanded station network with updated records reveal that much of China has experienced significant decreases in cloud cover over the last half of the Twentieth century. This conclusion is supported by the analysis of the more reliably observed frequency of cloud-free sky and overcast sky. The total cloud cover and low cloud cover have decreased 0.88% and 0.33% per decade, respectively, and cloud-free days have increased 0.60% and overcast days decreased 0.78% per decade in China from 1954-2001. Less cloud cover and more cloud-free skies, regardless of their causes, should have resulted in more solar radiation reaching the surface. Surprisingly, observation data show that both solar radiation and pan evaporation have decreased in most parts of China from 1955-2000, with solar radiation decreasing 3.1W/m2 and pan evaporation decreasing 39mm per decade. Combined with other evidences documented in previous studies, such as decreased sunshine duration, reduced visibility or clearness, and elevated aerosol optical depth, we speculated that increased air pollution may have produced a fog-like haze that reflected/absorbed radiation from the sun and resulted in less solar radiation reaching the surface(corroborated by the reduced pan evaporation), despite concurrent increasing trends in cloud-free sky over China.
DE: 0321 Cloud/radiation interaction
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1640 Remote sensing (1855)
DE: 3359 Radiative processes
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005