(B107) <<< Previous | Back to Abstracts Page | Next >>> (B202)
Mesoscale ocean turbulence and coherent structures as observed from Lagrangian data
M. Veneziani, A. Griffa, A. Reynolds, Z. Garraffo, E. Chassignet, and A. Mariano
RSMAS/University of Miami
cveneziani@rsmas.miami.edu(Abstract received 04/26/2005 for session B)
ABSTRACT
Lagrangian data provide direct information on ocean currents in terms of velocity and water particle dispersion. Extensive data sets of historical Lagrangian data are available today for most of the world oceans, both at the surface and in the ocean interior. Their statistical analyses have significantly contributed to improve our knowledge of the ocean circulation. In particular, Lagrangian data provide direct information about transport processes, allowing to identify the mesoscale eddy component. An importan conceptual question is whether the eddy transport can be considered approximately diffusive, as assumed in climate modeling and parameterizations, or whether it presents significant deviations due to the presence of coherent structures such as vortices and waves.
In this talk, the question of how to characterize and parameterize oceanic turbulence in presence of coherent structures is addressed considering both the historical data set of 700 m subsurface floats in the north-western Atlantic, and a numerical trajectory data set simulated within a high-resolution Miami Isopycnic Coordinate Ocean Model (MICOM). We focus on the regions of the Gulf Stream extension and recirculation, which are characterized by the presence of strong vortices and rings as shown by a number of looping trajectories, the so-called loopers. We study the statistical and dispersion properties of the mesoscale turbulent field, and verify the applicability of an appropriate Lagrangian Stochastic Model capable of describing the observed features.
(B107) <<< Previous | Back to Abstracts Page | Next >>> (B202)
2005 LAPCOD Meeting, Lerici, Italy, June 13-17, 2005