Estimation of vertical velocities associated with large scale dynamics in the Atlantic ocean.

alban lazar (LOCEAN-IPSL-UPMC, France)

CoAuthors

Soren François (LOCEAN-IPSL-UPMC, France); Siny Ndoye (LPAOSF-ESP-UCAD & LOCEAN-IPSL-UPMC, Senegal)

Event: 2017 Ocean Surface Topography Science Team Meeting

Session: Science II: Large Scale Ocean Circulation Variability and Change

Presentation type: Type Poster

Vertical velocities in the ocean are generally too weak to be measured at monthly to interanual time-scales. In particular, that is the case of the vertical movements associated to the large scale basin wide relatively slow dynamics. This prevents any accurate assessment of the thermohaline circulation return flow and the thermocline vertical ventilation (mass, heat, oxygen and carbon fluxes).
In this work, we compute the three-dimensional time-mean vertical velocities of an Atlantic basin simulation, using the density field and the linear vorticity balance (LVB). The validity of the LVB and the errors of the estimated velocities are quantified using the simulation as the reference.
It appears that large regions of the basin are dominated by the LVB dynamics, within the tropical, subtropical, and subpolar gyre, at various depth range, depending on spatial scale considered. The vertical velocity estimated field is accordingly accurate in many regions to first order, especially away from boundaries. The validity of the method also offers a way to interpret vertical movements at various depths in function of the better known horizontal flow.

 

Poster show times:

RoomStart DateEnd Date
Concerto Ballroom Thu, Oct 26 2017,14:00 Thu, Oct 26 2017,18:00
alban lazar
LOCEAN-IPSL-UPMC
France
alban.lazar@upmc.fr