HR: 0830h
AN: A31C-0060    [PDF]
TI: Solar cycle signals in northern hemisphere wave activity
AU: * Zhou, S
EM: shuntai.zhou@noaa.gov
AF: NOAA/NCEP/Climate Prediction Center, 5200 Auth Road, Rm 806, Camp Springs, MD 20746 United States
AU: Miller, A J
EM: alvin.miller@noaa.gov
AF: NOAA/NCEP/Climate Prediction Center, 5200 Auth Road, Rm 806, Camp Springs, MD 20746 United States
AB: Although there have been many indications of solar cycle influence on the Earth's climate from observational and statistical studies, the physical mechanism of Sun-Climate connections is thus far still unclear. One generally agreed, but unproved theory suggests that solar UV variation affects stratospheric ozone, which in turn affects stratospheric temperature and circulations. The stratospheric changes then propagate downward to the troposphere through modulation of tropospheric wave propagation and wave-mean flow interactions. To examine to what extent this theory is valid, we search for atmospheric regions where dynamical quantities including wave fluxes show, if any, the strongest apparent solar cycle. Based on the NCEP/NCAR Reanalysis data since 1979, we find that during solar maxima the northern hemisphere waves tend to be refracted more equatorward near the subtropical jet region, and wave forcing tends to enhance polar westerly wind. The meridional eddy heat flux also shows signals of solar cycle modulation in subpolar stratosphere, but the phase is somewhat different. Statistical and composite techniques are used to distinguish solar cycle effects from other external forcings, and to determine significance levels of analyzed solar signal in the dynamical quantities.
DE: 1600 GLOBAL CHANGE (New category)
DE: 1620 Climate dynamics (3309)
DE: 1650 Solar variability
DE: 3319 General circulation
DE: 3334 Middle atmosphere dynamics (0341, 0342)
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting