Variation of sea surface height at periods of 65–220 days in the subtropical gyre of the North Pacific

Abstract

spring and fall conditions. Although Qiu's study sheds light on one possible dynamical process for eddy production in the STCC region, there remain unknown statistical features of the SSH variations. In particular, his study focused on the eddy kinetic energy averaged over the entire STCC region with no discussion on the detailed spatial distribution of the SSH disturbances.The present paper examines statistical properties and detailed spatial distribution of the SSH disturbances in the STCC region using altimeter-derived SSH data spanning a 7 year period. The reminder of this paper is organized as follows: section 2 describes the SSH anomaly and hydrographic data used in this study. In section 3, we examine spectral properties of the SSH variations in the North Pacific using spectral analysis. Following this, we show the energy distribution of SSH variations in a particular frequency band and make a comparison with the locations of the multiple eastward flows. In section 4, features such as dominant spatial scales, propagation speeds and nonlinearity of the eddy variability are estimated by two-dimensional spectral analyses and composite analyses. We Data and Processing

The Kuroshio large meander formation in 2004 analyzed by an eddy‐resolving ocean forecast system

“…[4] Analyses of the satellite data have showed that mesoscale eddies with a spatial scale of 500 -800 km and a time scale of 45-180 days are active both south of Japan and east of Taiwan [e.g., Ebuchi and Hanawa, 2000;Kobashi and Kawamura, 2001]. Some observational studies suggested that these mesoscale eddies play important roles in the Kuroshio path variation south of Japan [Book et al, 2002;Ebuchi and Hanawa, 2003].…”

Study on SST front disappearance in the subtropical North Pacific using microwave SSTs

“…At the zone between 135°and 150°E, a low GM/ JSD zone separates the STF and KF. Its longitudinal range is consistent with the area that has relatively larger mesoscale sea surface height variability (Kobashi and Kawamura 2001). Therefore, our area of interest is the separated STF zone (20°-32°N, 135°-150°E).…”

Seasonal variations of the Hawaiian Lee Countercurrent induced by the meridional migration of the trade winds

“…There are other possible mechanisms. The interaction between mesoscale eddies (Kobashi and Kawamura 2001;Liu and Li 2007) and the mean flow could cause the HLCC to vary. The detailed investigations are needed in future.…”