Observational evidence of alternating zonal jets in the world ocean

Abstract

Multiple zonal jets with the east‐west velocity direction alternating with latitude are discovered in satellite altimetry data. The time‐varying jets are shown to populate every part of the world ocean and its marginal seas and are best seen in the anomaly of geostrophic vorticity. At midlatitudes the jets have a meridional wavelength of about 300 kms with r.m.s. sea level, velocity and vorticity values of 2.4 cm, 6.9 cm/s and 1.5 · 10 −6 s −1 , correspondingly. Realistic data from the high‐resolution OGCM run on the Earth Simulator are used to justify high vertical coherence of the jets structure and relevance of the jets to an evolving mesoscale eddy field. Strong coupling between the jets and mesoscale eddies is hypothesized.