HR: 10:50h
AN: B32A-03    [Abstracts]
TI: Multidecadal variations in the direct and diffuse solar irradiance
AU: * Liepert, B G
EM: liepert@ldeo.columbia.edu
AF: Lamont Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY 10964 United States
AB: It has been reported that diffuse radiation plays a relatively more important role in photosynthesis and hence in carbon uptake by plants than the total solar irradiance reaching the canopy. Clouds scatter sunlight and also are responsible for the rainfall patterns. Many sites worldwide exist where diffuse solar irradiance has been measured at the ground for several decades. Here we plan to present an overview of existing data sets and their possible temporal variability. The possible causes of this variability will be discussed together with the possible impacts on the water and carbon cycle. Clouds scatter sunlight and increase diffuse light but also form rain whereas aerosols scatter sunlight and potentially dry the atmosphere. An assessment of the magnitude of diffuse radiative variability and the impacts of various natural (volcanic eruptions, clouds) and anthropogenic disturbances will be discussed.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
DE: 3359 Radiative processes
SC: Biogeosciences [B]
MN: Fall Meeting 2005