Altimeter-Derived Seasonal Circulation on the SW Atlantic Shelf 27° -43°S

Published in Journal of Geophysical Research: Oceans, v. 120:3391–3418
Authors

Scrub, P.T., James, C., Combes, V., Matano, R.P., Piola, A.R., Palma, E.D., Saraceno, M., Guerrero, R.A., Fenco, H. and Ruiz-Etcheverry, L.A.

 
Publication year 2015
DOI https://doi.org/10.1002/2015JC010769
Affiliations
  • College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, USA
  • Departamento Oceanografıa, Servicio de Hidrografıa Naval and Departamento de Ciencias de la Atmosfera y los Oc  eanos, Universidad de Buenos Aires, and UMI/IFAECI, CONICET-CNRS-UBA, Buenos Aires, Argentina
  • Departamento de Fısica, Universidad Nacional del Sur and Instituto Argentino de Oceanografıa, Bahıa Blanca, Argentina
  • Centro de Investigaciones del Mar y la Atmosfera, CONICET, Departamento de Ciencias de la Atm  osfera y los Oc  eanos, Universidad de Buenos Aires, and UMI/IFAECI, CONICET-CNRS-UBA, Buenos Aires, Argentina
  • Instituto Nacional de Investigacion y Desarrollo Pesquero, Mar del Plata, Argentina

 
IAI Program

CRN3
IAI Project CRN3070
Keywords
Altimeter sea surface height
seasonal circulation
SW Atlantic Ocean

Highlights

  • Altimeters can resolve the seasonal circulation over the SW Atlantic coastal shelf
  • Seasonal changes are primarily wind-driven north of the Rio de la Plata
  • Our results agree with previous studies using models and field surveys

Abstract

Altimeter sea surface height (SSH) fields are analyzed to define and discuss the seasonal circulation over the wide continental shelf in the SW Atlantic Ocean (278&ndash438S) during 2001&ndash2012. Seasonal variability is low south of the Rio de la Plata (RdlP), where winds and currents remain equatorward for most of the year. Winds and currents in the central and northern parts of our domain are also equatorward during autumn and winter but reverse to become poleward during spring and summer. Transports of shelf water to the deep ocean are strongest during summer offshore and to the southeast of the RdlP. Details of the flow are discussed using mean monthly seasonal cycles of winds, heights, and currents, along with analyses of Empirical Orthogonal Functions. Principle Estimator Patterns bring out the patterns of wind forcing and
ocean response. The largest part of the seasonal variability in SSH signals is due to changes in the wind forcing (described above) and changes in the strong boundary currents that flow along the eastern boundary of the shelf. The rest of the variability contains a smaller component due to heating and expansion of the water column, concentrated in the southern part of the region next to the coast. Our results compare well to previous studies using in situ data and to results from realistic numerical models of the regional circulation.