We are studying a new family of anisotropic, oceanic features, commonly referred as 'zonal jets' discovered recently using satellite altimetry, high-resolution mean dynamic topography and advanced ocean circulation models. While these features reveal a broad diversity of characteristics and physics, this project aims to investigate the dynamics of two distinct types that have been validated by in situ observations and are reproduced by advanced numerical models. The first type is evident in high-resolution mean dynamic ocean topography, and corresponds to zonally elongated features that are especially distinct in the eastern parts of all subtropical oceans. Each such jet-like feature appears to have some kind of source at its eastern tip. These features include known jets such as the Hawaiian Lee Countercurrent and the Azores Current and suggest a rich diversity of possible sources. The second type is quasi-periodic nearly zonal jet-like structures that propagate toward the equator and appear confined within subtropical gyres. Sea level simulated by the high-resolution ocean model for the Earth Simulator and by the Regional Ocean Model System shows much similarity with the altimetry data. However, differences remain significant and reflect either difference of forcing, or the impact of incomplete dynamics or parameter choices. We use high-resolution satellite observations of the ocean surface topography, as well as other satellite data and historical and modern in-situ observations, in combination with analysis of high-resolution ocean model simulations and experiments to explore the internal dynamics and sources of these jet-like structures.
Dynamics Of Anisotropic Mean And Time-Varying Structures Of Ocean Circulation