HR: 08:00h
AN: A51D-01 INVITED     [Abstracts]
TI: Modern observations of the Earth's albedo
AU: * Palle, E
EM: epalle@iac.es
AF: Instituto de Astrofisica de Canarias, Via Lactea s/n, La Laguna, E38205, Spain
AB: Broadly speaking, changes in climate depend essentially on three basic parameters, the amount of incident sunlight, the fraction of this sunlight that is reflected by the Earth, and the trapping of the Earth's infrared radiation by clouds and greenhouse gases. While substantial efforts have been made over the past few decades at characterizing the effects of both the solar irradiance and the greenhouse gases on climate, significant questions remain regarding the Earth's reflectance -or albedo. Recent estimates of its variability from a range of sources indicate a much larger-than-expected, and not currently understood, inter-annual and decadal variability. Here, I will focus on the available datasets related to Earth's reflectance, in order to assess the observational constraints on the models. We find a consistent picture among all datasets of an albedo decreased during 1985-2000 between 2-3 and 6-7 W/m2, which is highly climatically significant. The largest discrepancy among the datasets occurs during 2000-2004, when some present an increasing reflectance trend, while others show a steady decrease.
DE: 0321 Cloud/radiation interaction
DE: 0360 Radiation: transmission and scattering
DE: 0994 Instruments and techniques
DE: 1610 Atmosphere (0315, 0325)
DE: 3300 ATMOSPHERIC PROCESSES
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly