HR: 08:00h
AN: GC21A-01 INVITED     [Abstracts]
TI: From Solar Dimming to Solar Brightening: Observations, Modeling, Impacts
AU: * Wild, M
EM: martin.wild@env.ethz.ch
AF: 1 Institute for Atmospheric and Climate Science ETH, Swiss Federal Institute of Technology, Universit„tsstr. 16, Zurich, CH 8092 Switzerland
AU: Ohmura, A
EM: atsumu.ohmura@env.ethz.ch
AF: 1 Institute for Atmospheric and Climate Science ETH, Swiss Federal Institute of Technology, Universit„tsstr. 16, Zurich, CH 8092 Switzerland
AU: Feichter, J
EM: feichter@dkrz.de
AF: Max Planck Institute for Meteorology, Bundesstr. 53, Hamburg, 20146 Germany
AU: Stier, P
EM: philip.stier@caltech.edu
AF: Max Planck Institute for Meteorology, Bundesstr. 53, Hamburg, 20146 Germany
AU: Robock, A
EM: robock@envsci.rutgers.edu
AF: Department of Environmental Sciences , Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901-8 United States
AU: Li, H
EM: hli@envsci.rutgers.edu
AF: Department of Environmental Sciences , Rutgers University, 14 College Farm Road, New Brunswick, NJ 08901-8 United States
AB: Recent evidence suggests that the amount of solar radiation reaching the earth surface is not stable over time but exhibits significant decadal variations. These variations, in addition to the changes in thermal radiation induced by alterations in greenhouse gases, cause changes in radiative forcings which may significantly affect surface climate. Observations from the Global Energy Balanced Archive (GEBA) and Baseline Surface Radiation Network (BSRN) databases at the Swiss Federal Institute of Technology suggest that surface solar radiation, after decades of dimming, reversed into a brightening since the mid 1980s at widespread locations. These changes are in line with a recovery of atmospheric transparency, possibly related to reduced aerosol loadings due to air pollution control and the breakdown of industry in formerly Communist countries. Not many GCMs currently represent aerosol effects with a degree of sophistication to capture such effects, but we used a special version of the Max Planck Institute for Meteorology GCM which includes a detailed aerosol scheme, ECHAM5-HAM, to investigate the observed trends. In addition, we investigate the potential impact of the variations in surface radiation on other elements of the climate system, such as soil moisture, which shows changes in line with the changes in radiation. Reference: Wild, M., Gilgen, H., Roesch, A., Ohmura, A., Long, C., Dutton, E., Forgan, B., Kallis, A., Russak, V., Tsvetkov, A., 2005: From dimming to brightening: Decadal changes in solar radiation at the Earth's surface. Science , 308, 847-850
DE: 0321 Cloud/radiation interaction
DE: 0360 Radiation: transmission and scattering
DE: 1620 Climate dynamics (0429, 3309)
DE: 1626 Global climate models (3337, 4928)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
SC: Global Climate Change [GC]
MN: Fall Meeting 2005