title: Altimeter-derived seasonal circulation on the southwest Atlantic shelf: 27°-43°S.
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 (27°-43°S) during 2001-2012. 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.
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA.
authors.forename: P Ted
authors.initials: PT
authors.lastname: Strub
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA.
authors.forename: Corinne
authors.initials: C
authors.lastname: James
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA.
authors.forename: Vincent
authors.initials: V
authors.lastname: Combes
authors.affiliation: College of Earth, Ocean, and Atmospheric Sciences Oregon State University Corvallis Oregon USA.
authors.forename: Ricardo P
authors.initials: RP
authors.lastname: Matano
authors.affiliation: Departamento Oceanografía, Servicio de Hidrografía Naval and Departamento de Ciencias de la Atmósfera y los Océanos Universidad de Buenos Aires, and UMI/IFAECI, CONICET-CNRS-UBA Buenos Aires Argentina.
authors.forename: Alberto R
authors.initials: AR
authors.lastname: Piola
authors.affiliation: Departamento de Física Universidad Nacional del Sur and Instituto Argentino de Oceanografía Bahía Blanca Argentina.
authors.forename: Elbio D
authors.initials: ED
authors.lastname: Palma
authors.affiliation: Centro de Investigaciones del Mar y la Atmósfera, CONICET, Departamento de Ciencias de la Atmósfera y los Océanos Universidad de Buenos Aires, and UMI/IFAECI, CONICET-CNRS-UBA Buenos Aires Argentina.
authors.forename: Martin
authors.initials: M
authors.lastname: Saraceno
authors.affiliation: Instituto Nacional de Investigación y Desarrollo Pesquero Mar del Plata Argentina.
authors.forename: Raul A
authors.initials: RA
authors.lastname: Guerrero
authors.affiliation: Instituto Nacional de Investigación y Desarrollo Pesquero Mar del Plata Argentina.
authors.forename: Harold
authors.initials: H
authors.lastname: Fenco
authors.affiliation: Centro de Investigaciones del Mar y la Atmósfera, CONICET, Departamento de Ciencias de la Atmósfera y los Océanos Universidad de Buenos Aires, and UMI/IFAECI, CONICET-CNRS-UBA Buenos Aires Argentina.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Ruiz-Etcheverry
keywords: altimeter; circulation; coastal; seasonal; shelf