Earth Lightens Up
In the May 6 issue of Science magazine, a paper co-authored by a researcher from DOE’s Atmospheric Radiation Measurement (ARM) Program shows an increase in the amount of solar energy reaching the earth. This increase is a reversal in the trend of decreased downwelling energy that was observed during the 1950s until the mid to late 80s. The article highlights more recently available and expansive data, such as long-term cloudless sky estimates from algorithms developed through the ARM Program. Because a decrease in solar energy input to the surface would decrease the amount of warming of the surface air, the earlier trend may have acted to somewhat mask the projected global greenhouse warming trend. With the current trend, the projected greenhouse warming signal might become more apparent. For this study, the Global Energy Balance Archive (GEBA) was the main source of data prior to 1990, and the Baseline Surface Radiation Network (BSRN) of the World Climate Research Program, of which the ARM Climate Research Facility is a participant, was used for data from 1992 on.
Wild, M., H. Gilgen, A. Roesch, A. Ohmura, C. N. Long, E. G. Dutton, B. Forgan, A. Kallis, V. Russak, and A. Tsvetkov, (2005): From dimming to brightening: Decadal changes in solar radiation at the Earth’s surface, Science, 308, Issue 5723, 847-850, [DOI:10.1126/science.1103215].