Multiscale variabilities in global sea surface temperatures and their relations with tropospheric climate patterns

• Main Authors: David B. Enfield, Alberto M. Mestas-nun Ez
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1999
• Subjects: Greenland; Pacific; North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.586.840; http://www.aoml.noaa.gov/phod/docs/gmsst/manuscript.pdf

El Niño–Southern Oscillation (ENSO) is a global phenomenon with significant phase propagation within and between basins. This is captured and described in the first mode of a complex empirical orthogonal function (CEOF) analysis of sea surface temperature anomaly (SSTA) from the midnineteenth century through 1991. The global ENSO from the SSTA data, plus a linear trend everywhere, are subsequently removed in order to consider other global modes of variability uncontaminated by the intra- and interbasin effects of ENSO. An ordinary EOF analysis of the SSTA residuals reveals three non-ENSO modes of low-frequency variability that are related to slow oceanic and climate signals described in the literature. The first two modes have decadal to multidecadal timescales with high loadings in the Pacific. They bear some spatial similarities to the ENSO pattern but are broader, more intense at high latitudes, and differ in the time domain. A CEOF analysis confirms that they are not merely the phase-related components of a single mode and that all three modes are without significant phase propagation. The third mode is a multidecadal signal with maximal realization in the extratropical North Atlantic southeast of Greenland. It is consistent with studies that have documented connections between North Atlantic SSTA and the tropospheric North Atlantic Oscillation (NAO). All three SSTA modes have midtropospheric associations related to previously classified Northern Hemisphere