HR: 16:40h
AN: GP54A-02 INVITED     [Abstracts]
TI: Sun's Direct and Indirect Role in Climate Change
AU: * Goode, P R
EM: pgoode@bbso.njit.edu
AF: Big Bear Solar Observatory, New Jersey Institute of Technology 40386 N. Shore Lane, Big Bear City, CA 92314, United States
AB: Broadly, the Earth's climate is driven by the Sun's output, the Earth's reflectance and the Earth's thermal emission. Of these three fundamental climate variables, the Earth's reflectance is the least well-studied. In fact, variations in reflectance are being implicitly ignored when solar cycle variables are treated as proxies for the net sunlight reaching Earth. Variations in the solar irradiance have been precisely measured for more than a quarter century combining observations from various satellites, and here we review the physical reasons why the Sun's irradiance variations over a solar cycle, as well as over longer historical times have climatologically insignificant variations. So, why are there terrestrial signatures of the solar cycle in climate records, or periods like the Maunder Minimum corresponding to times when the Sun was less active? If the variations of irradiance over the most recent solar cycles were typical, then changes in the net sunlight reaching Earth is a logical source of the terrestrial signatures of solar variability. Here, the relevant component of the net sunlight is the much less well-studied global reflectance of the Earth. Small variations in the Sun's output could be amplified in the much less well-studied terretrial albedo. We review our knowledge of the Earth's reflectance from terrestrial measurements of the earthshine and discuss future plans for measurements of terrestrial reflectance.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 7522 Helioseismology
DE: 7536 Solar activity cycle (2162)
DE: 7538 Solar irradiance
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly