2002: Inter-hemispheric decadal variations in SST, surface wind, heat flux and cloud cover over the Atlantic

• Main Authors: Youichi Tanimoto, Shang-ping Xie
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.145.8895; http://iprc.soest.hawaii.edu/~xie/tani02_jmsj.pdf

Atlantic decadal climate variations are studied using marine meteorological observations. To remove artificial interhemispheric correlation, we perform empirical orthogonal function (EOF) analysis of sea surface temperature (SST) variability separately for the North and South Atlantic. The first EOF for the North (South) Atlantic in the decadal (8–16 years) band features a meridional tripole (dipole). In the tropics, the northern and southern leading EOFs form a meridional dipole with a center of action at 15 on either side of the equator. The leading sea level pressure (SLP) EOFs for the North and South Atlantic each feature a center of action that is displaced poleward of the tropical SST extreme, at 30 latitude. The SLP center of action in the North Atlantic has a barotropic structure and contributes significantly to surface wind variability in the tropics. Despite being derived from statistically independent data samples, the principle components for the leading SST and SLP EOFs (four in total) are significantly correlated with one another, indicative of the existence of an interhemispheric mode spanning the entire Atlantic Ocean. The same analysis for a longer SST record suggests that this pan-Atlantic decadal variability exists throughout the 20th century. In the North Atlantic, composite analysis of wind velocity and heat fluxes based on the PCs of the