ESC seminar No. 66

Submesoscale ocean dynamics: Eddy fluxes and the forward cascade

Date
Thursday, July 5, 2012, 14:00-15:00
Place
Conference room , 1F Earth Simulator Research Building, YES
Speaker
Prof. Amit Tandon
(University of Massachusetts Dartmouth)
Language
English

Abstract

Subthermocline circulation in the tropical North Pacific Ocean(2-30N) is investigated using profiling float temperature-salinity data from the International Argo and the Origins of the Kuroshio and Mindanao Current (OKMC) projects. Three well-defined eastward jets are detected beneath the wind-driven, westward-flowing North Equatorial Current. Dubbed the North Equatorial Undercurrent(NEUC) jets,
these subthermocline jets have a typical core velocity of 2-5 cm/s and are spatially coherent from the western boundary to about 120W across the North Pacific basin. Centered around 9N, 13N, and 18N in the western basin, the NEUC jet cores tend to migrate northward by ~ 4 degs. in the eastern basin. Vertically,
the cores of the southern, central, and northern NEUC jets reside on the 26.9, 27.2, and 27.3 sigma_theta surfaces, respectively, and they tend to shoal to lighter density surfaces, by about 0.2 sigma_theta, as the jets progress eastward. For more details, http://www.soest.hawaii.edu/oceanography/bo/NEUC_GRL2013.pdf .
In the seminar, the NEUC jet's formation mechanisms will be presented both theoretically and using OFES and simplified ocean circulation models. The importance of triadly interacting baroclinic Rossby waves will be emphasized.

Contact

Hideharu Sasaki
Earth Simulator Center
TEL: 045-778-5843
e-mail: sasaki