J1.1
The direct effect of stratospheric variability on the tropospheric circulation
David W. J. Thompson, Colorado State Univ., Ft. Collins, CO
Recent observational and numerical evidence suggests that stratospheric processes play an important role in driving tropospheric climate variability on both intraseasonal and climate change timescales. In this talk, I will argue that the amplitude of the tropospheric response to stratospheric variability is consistent with the direct effect of anomalous wave driving at stratospheric levels. The result contradicts the current orthodoxy that internal tropospheric dynamics are required to explain the observed amplitudes at tropospheric levels. It is further argued that the ~two month persistence of the tropospheric response to stratospheric variability is consistent with the direct effect of anomalous radiative cooling at stratospheric levels. Implications for the interpretation of recent climate change are discussed.
Joint Session 1, dynamics and Changes of climate modes, including annular modes (Joint with Middle Atmosphere, Fluid Dynamics and Climate Variations)
Monday, 13 June 2005, 10:30 AM-6:15 PM, Ballroom D
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