In this thesis, I study the time-varying behavior of a ventilated thermocline with basin scales at annual and decadal time scales. The variability is forced by three external forcings: the wind stress (chapter 3), the surface heat flux (chapter 4) and the upwelling along the eastern boundary (chapter 5). It is found that the thermocline variability is forced mainly by wind in a shadow zone whil...

We are interested here in describing the linear response of a highly rotating fluid to some surface stress tensor, which admits fast time oscillations and may be resonant with the Coriolis force. In addition to the usual Ekman layer, we exhibit another much larger boundary layer, and we prove that for large times, the effect of the surface stress may no longer be localized in the vicinity of th...

Variations in the warm water volume (WWV) of the equatorial Pacific Ocean are considered a key element of the dynamics of the El Niño–Southern Oscillation (ENSO) phenomenon. WWV, a proxy for the upperocean heat content, is usually defined as the volume of water with temperatures greater than 208C. It has been suggested that the observed variations in WWV are controlled by interplay among meridi...

A plume often results when a river discharges fresh water into the nearshore waters. This thesis combines both hydrographic data and idealized numerical simulations to examine how ambient currents and winds influence the transport and mixing of plume waters. The alongshore transport of freshwater is studied using a numerical model. In the absence of ambient currents, the downstream coastal curr...

Abstract A remarkably consistent Lagrangian upwelling circulation at monthly and longer time scales is observed in a 17-yr series of current profiles 12 m water on the southern New England inner shelf. The strongest summer, with magnitude ∼1 cm s −1 , which flushes shelf ∼2.5 days. average winter about one-half summer circulation, but larger month-to-month variations driven, part, by cross-shel...

This thesis focuses on the development, analysis and evaluation of methods for the retrieval of ocean surface winds with synthetic aperture radar (SAR) and surface currents with infrared (IR) radiometer sensors. The SAR wind speed retrievals are based on geophysical model functions using wind directions obtained with two approaches. The first approach determines wind directions from the spatial...

[1] We examine the July 2008 to July 2010 circulation over the central Bering Sea shelf using measurements at eight instrumented moorings, hindcast winds and numerical model results. At sub-tidal time scales, the vertically integrated equations of motion show that the cross-shelf balance is primarily geostrophic. The along-shelf balance is also mainly geostrophic, but local accelerations, wind ...

We investigated the impact of assimilating a mapped dataset of subsurface ocean currents into an ocean state estimation. We carried out two global ocean state estimations from 2000 to 2007 using the K7 four-dimensional variational data synthesis system, one of which included an additional map of climatological geostrophic currents estimated from the global set of Argo floats. We assessed the re...

Direct measurements of the air–sea turbulent fluxes of momentum and heat, along with surface currents, waves and supporting meteorological variables, were acquired during a recent field campaign. Surface currents, measured from a very high frequency radar, were found to steer the stress away from the mean wind direction. Although this effect has been reported in a recent scatterometer study, th...