HR: 1340h
AN: A43D-0129    [Abstracts]
TI: 22 Views of the Global Albedo - Comparison Between 20 GCMs and 2 Satellites
AU: * Bender, F A
EM: frida@misu.su.se
AF: Stockholm University, Department of Meteorology, Svante Arrhenius v. 12, Stockholm, 10691 Sweden
AU: Ekman, A
EM: annica@misu.su.se
AF: Stockholm University, Department of Meteorology, Svante Arrhenius v. 12, Stockholm, 10691 Sweden
AU: Rodhe, H
EM: rodhe@misu.su.se
AF: Stockholm University, Department of Meteorology, Svante Arrhenius v. 12, Stockholm, 10691 Sweden
AU: Charlson, R J
EM: charlson@chem.washington.edu
AF: University of Washington, Chemistry Library, Room 34 Box 351640 , Seattle, WA 98195-1640 United States
AB: The climate in terms of global mean temperature has remained remarkably stable over the Holocene. Given the major role that the planetary albedo plays in the global energy balance, it seems reasonable to beleive that the albedo too has remained stable. The albedo is determined by surface properties, as well as atmospheric factors, in particular clouds and their radiative properties. Before addressing questions of what processes and feedbacks may cause the stability in albedo and/or in climate, we need to have a clear picture of the albedo itself, and its spatial and temporal variability. The main source of global TOA radiative flux data is satellite measurements. As a complement to observations (that are sparse and can not be used for prediciton) models of the climate system can be a powerful tool. Naturally, since consistency is the simplest indicator of their accuracy, agreement between models and measurements is desired. In this study we consider measurements made by ERBE (Earth Radiation Budget Exepriment) and CERES (Clouds and the Earth's Radiant Energy System), as well as output from coordinated simulations with 20 different GCMs, performed in support of the IPCC 4th assessment report, and evaluate their different views of the albedo. In an attempt to bridge the gap between models and measurements, we carry out a systematic comparison between the albedo output from the 20 GCMs and the data from the ERBE and CERES satellite campaigns. Studying absolute levels, seasonal cycles, temporal trends and spatial distribution of albedo, we find that models and observations differ in many aspects. We hope that by pointing out and quantifying differences we can inspire both modellers and experimentalists to refine their products.
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1626 Global climate models (3337, 4928)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005