HR: 10:35h
AN: A52B-02 INVITED     [Abstracts]
TI: Impact of Solar Variability on the Earth's Climate Patterns
AU: * Ruzmaikin, A
EM: Alexander.Ruzmaikin@jpl.nasa.gov
AF: Alexander Ruzmaikin, Jet Propulsion Laboratory, mail stop 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AB: We discuss the effect of solar variability on the Earth climate patterns. The climate patterns are naturally excited in the noisy atmosphere-ocean dynamical system as deviations (anomalies) from a global (mean) state. Some of the climate patterns couple the upper and lower atmosphere and are affected by the ocean. An example of this type of climate pattern is the Northern Annular Mode (NAM), a climate anomaly with two basic states corresponding to higher pressure at high latitudes with a band of lower pressure at lower latitudes and the other way round (Thompson & Wallace, 1998; Baldwin & Dunkerton, 1999). Two states of the NAM arise due to the dynamical interaction of planetary waves and zonal mean wind (Limpasuvan & Hartmann, 2001; Ruzmaikin et al., 2006). The NAM accounts for 23% of atmospheric variability at sea level and about 50% of the variability in the stratosphere. Solar variability influences the NAM through the change of the UV flux in upper atmosphere. The influence depends on the phase of the Quasi Biennial Oscillation and time in the winter season (Ruzmaikin & Feynman, 2002). We discuss a possible mechanism by which solar variability can affect the NAM and the climate patterns in general (involving the Rossby-Palmer conjecture, Palmer, 1999). In contrast to the standard linear evaluation of climate sensitivity to an external forcing we outline a non-linear approach to the forcing problem. In particular, we evaluate the distributions of residence times spent in each state of the pattern and show how these distributions depend on external forcing caused by the anthropogenic and solar changes. References: Thompson, D. W. J. & J. M. Wallace, Geophys. Res. Lett., 25, 1297, 1998; Baldwin, M. P. & T. J. Dunkerton, J. Geophys. Res. 104, 30,937, 1999; Limpasuvan, V., & D. Hartmann, J. Climate, 13, 4414, 2001; Ruzmaikin, A., J, Feynman, J. Geophys. Res., 107, D14, 10.1029/2001JD001239, 2002; Ruzmaikin, A., J. K. Lawrence & A. C. Cadavid, J. Atmos. Space Phys., 68, 1311, 2006; Palmer, T. N., Bull. Amer. Meteor. Soc., 79, 1412 1998.
DE: 1650 Solar variability (7537)
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 7974 Solar effects
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly