The methods of identifying mesoscale eddies from satellite altimetry data

• Grant number: 13/02355-0
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Effective date (Start): April 01, 2013
• Effective date (End): July 31, 2013
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Physical Oceanography
• Principal Investigator: Olga Tiemi Sato
• Grantee: Ana Beatriz de Figueiredo Melo Villas Boas
• Supervisor: Alexis Chaigneau
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Research place: Laboratoire d’Etudes en Géophysique et Océanographie Spatiales (LEGOS), France
• Associated to the scholarship: 12/21243-6 - The contribution of mesoscale eddies to the surface heat budget in the South Atlantic, BP.MS

Abstract

Mesoscale oceanic eddies are quasi-circular coherent structures having typical horizontal scales of 10-100 km, vertical extent of 100-1000 m, and duration life of several weeks/months. Because of their capability to transport tracers along their trajectories, they play an important role in ocean dynamics and budgets. Since the launch of satellite altimetry missions ERS, TOPEX/Poseidon, Jason and Envisat it became possible to study mesoscale activity from sea level anomaly (SLA) data with great accuracy. Many methods of identifying mesoscale eddies in the ocean from altimetry data have been developed in the last decade and most are based either on dynamical or geometrical properties of the eddies. Among the existing methods, two are now commonly used: the Okubo-Weiss (OW) method which identifies eddies as regions where vorticity dominates the deformation field and the winding-angle (WA) method that considers that eddies are associated with closed flow streamlines. In this project, we aim to review both the OW and WA algorithms and apply these methods to SSH data to identify mesoscale eddies in the South Atlantic basin. Based on these two commonly used methods, we will the first describe the main eddy characteristics in the study region. Then, combining altimetry information and heat flux data at the ocean-atmosphere interface, we aim to estimate the role of mesoscale eddies on the surface heat budget variability. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

VILLAS BOAS, A. B.; SATO, O. T.; CHAIGNEAU, A.; CASTELAO, G. P.. The signature of mesoscale eddies on the air-sea turbulent heat fluxes in the South Atlantic Ocean. Geophysical Research Letters, v. 42, n. 6, p. 1856-1862, MAR 28 2015. (12/21243-6, 13/11825-0, 13/02355-0, 08/58101-9)