An Ocean Resonance in the Southeast Pacific

• Published in: Geophysical research letters Vol. 29; no. 8; pp. 93-1 - 93-3
• Main Authors: Webb, David J., de Cuevas, Beverly A.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01.04.2002; Blackwell Publishing Ltd
• Subjects: Correlation; Decay; Information Related to Geographic Region; Marine; Mathematical models; Numerical modeling; Ocean models; Oceanography; Oceans; Pacific Ocean; Physical; Response functions; Sea level variations; Time series; Topography
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2001GL014259

Satellite Altimeter observations of sea surface height show an extensive region of high variability in the Southeastern Pacific which previous studies have suggested is a Rossby wave trapped by topography. Here we investigate the feature using results from a high‐resolution global ocean model. We calculate the empirical orthogonal modes and find that 29% of the SSH variability is due to a single mode. We correlate the time series of the mode with the local Ekman pumping and find that the correlation is largest when the wind curl is averaged over a region roughly the size of the mode. We calculate the response function relating the two time series and find that it is dominated by a resonance at zero frequency with a decay time of about two days. We conclude that the feature is a highly damped geostrophic mode of the ocean.