3.1
Mid-latitude atmospheric influence on tropical Pacific climate variability
Daniel J. Vimont, University of Wisconsin, Madison, WI
Recent research has identified mechanisms by which mid-latitude atmospheric variability can affect Pacific and Atlantic tropical climate through associated changes in the tropical and subtropical trade winds. These trade wind fluctuations alter the underlying sea surface temperature, exciting coupled feedbacks in the tropics and subtropics that persist through the following spring and summer. Of paticular note is the finding that in the Pacific, these tropical coupled feedbacks appear to be an especially efficient means of exciting El Nino - Southern Oscillation (ENSO) variability in models and in observations. We present research that illustrates this mechanism in observations and in models, and show evidence for positive coupled feedbacks in the tropics that appear to enhance the seasonal persistence of off-equatorial tropical variability. These results may indicate enhanced seasonal predictability of tropical variability, and of ENSO. .
Session 3, Atmospheric Oscillations (Room 608)
Monday, 12 January 2004, 10:45 AM-12:00 PM, Room 608
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