for Journal of Climate
We examine the seasonality and spatial patterns of tropical climate signals in the Antarctic for the late 1950s to present, and discuss these linkages in the context of two distinct dynamical mechanisms. Results are illustrated through regressions of Antarctic station temperature data and ice core r...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2011
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.384.916 http://www.cgd.ucar.edu/cas/cdeser/Docs/submitted.schneider.tropics.may11.pdf |
| Summary: | We examine the seasonality and spatial patterns of tropical climate signals in the Antarctic for the late 1950s to present, and discuss these linkages in the context of two distinct dynamical mechanisms. Results are illustrated through regressions of Antarctic station temperature data and ice core records upon global fields of sea surface temperature, sea level pressure and precipitation. Temperature and ice core anomalies in the Peninsula region and adjoining areas of West Antarctica are significantly impacted by the Pacific-South American (PSA) pattern, interpreted as a Rossby wave-train driven by anomalous tropical deep convection during ENSO events. This pattern is most evident in the austral spring, and supports recent studies suggesting that conditions for Rossby wave propagation in the extratropical Southern Hemisphere atmosphere are most favorable during this season. However, during austral summer at the peak of the ENSO cycle, temperature anomalies at East Antarctic coastal stations exhibit significant correlations with tropical Pacific anomalies. This linkage reflects the influence of anomalous tropical heating on the position and strength of the subtropical jets and is consistent with changes in eddy momentum fluxes that alter the mean meridional circulation as suggested in previous studies. Of the ice cores that exhibit tropical linkages, most tend to be associated with the PSA |
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