85th AMS Annual Meeting

Tuesday, 11 January 2005: 5:00 PM
Interannual Variability of Surface Radiation Budget
Shashi K. Gupta, AS&M, Hampton, VA; and P. W. Stackhouse Jr., S. J. Cox, J. C. Mikovitz, M. Chiacchio, and T. Zhang
Poster PDF (278.9 kB)
A twelve-year-plus (July 1983 to October 1995) global dataset of surface shortwave (SW) and longwave (LW) radiative parameters on a 1 deg. x 1 deg. grid was recently completed under the NASA/GEWEX Surface Radiation Budget (SRB) Project at the NASA Langley Research Center (LaRC). Both SW and LW fluxes were derived with two sets of radiation algorithms: one set designated as primary and the other as quality-check. Cloud properties derived from ISCCP pixel level (DX) data, temperature and humidity profiles from GEOS-1 reanalysis, and column ozone from TOMS archives were used as inputs to the algorithms. Several top-of-atmosphere (TOA) radiation budget parameters were also derived with the primary algorithms. Surface fluxes from all algorithms were extensively validated with ground-based measurements obtained from the Baseline Surface Radiation Network (BSRN) and the Global Energy Balance Archive (GEBA). The LaRC Atmospheric Sciences Data Center (ASDC) has put this dataset on the worldwide web (http://eosweb.larc.nasa.gov/) to make it available to the entire science community.

The above dataset was used to study the interannual variability of SRB parameters associated with regional/global phenomena, such as the El Nino/La Nina episodes which occurred during the period of this dataset and the North Atlantic Oscillation (NAO). The variability was examined in terms of surface flux anomalies derived from the primary algorithm products using time series and EOF/CCA analysis. Corresponding TOA flux and atmospheric forcing anomalies were derived using satellite measurements from the Earth Radiation Budget Experiment (ERBE) and also using primary algorithm products. Surface, TOA, and atmospheric flux anomalies over Tropical Pacific Ocean showed strong correlations with each other for all El Nino/La Nina episodes. We now expand the analysis to show the correlation of these processes with anomalies at larger spatial scales. A similar analysis is shown for the N. American and Euro-Asian regions from the NAO. These variabilities are related to time series anomalies from solar radiation measurements from the World Radiation Data Center at the surface during the period. Thus, the analysis will be used to explore the relationships between anomalies at points and regions owing to the episodic processes identified above. Also, surface flux anomalies associated with Mt. Pinatubo eruption were found to be significant over tropical regions and correlated well with corresponding TOA flux anomalies. The strong correspondence between surface and TOA anomalies, especially when the latter were derived from independent satellite measurements, greatly enhances the credibility of this dataset.

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