Evidence for tropical SST influence on Antarctic polar atmospheric dynamics

A Singular Value Decomposition analysis is applied to climatological data to determine the modes of variability of monthly mean Sea Surface Temperature (SST) in the tropics coupled with the southern hemisphere stratospheric polar vortex intensity for the 1958 to 2006 period and to identify the tropi...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Grassi, Barbara, Redaelli, Gianluca, Visconti, Guido
Format: Article in Journal/Newspaper
Language:English
Published: 2009
Subjects:
Online Access:https://www.openaccessrepository.it/record/205096
https://doi.org/10.1029/2009gl038092
Description
Summary:A Singular Value Decomposition analysis is applied to climatological data to determine the modes of variability of monthly mean Sea Surface Temperature (SST) in the tropics coupled with the southern hemisphere stratospheric polar vortex intensity for the 1958 to 2006 period and to identify the tropical region strongly influencing the high latitude stratospheric dynamics. Two subsets of data have been considered by explicitly taking into account the phase of the Pacific Decadal Oscillation (PDO). The study evidences a shift of the tropical region affecting the polar vortex from the Western Pacific to the Indoâ€Pacific Ocean, driven by the modulation of the SST pattern, due to the phase of the PDO. The analysis shows in both cases (years with positive/negative PDO phases) a high degree of correlation between an SST related index, calculated from NOAA/ERSST and HadISST datasets, and an index of the polar vortex intensity based on ECMWF data.