Acessibilidade / Reportar erro

Instabilidade linear de cisalhamento vertical em jatos geofísicos meridionais

The study of linear vertical shear instability of meridional (north-south) jets is conducted via an unidimensional hydrodynamic model, based on quasi-geostrophic potential vorticity conservation. The shape of the vertical jet profiles are motivated by the Brazil Current-Intermediate Western Boundary Current System that flows off the Brazilian Southeast coast and are built with the aim to satisfy necessary conditions for occuring baroclinic instability. The hydrodynamic model is based on Johns (1988) and its formulation is presented without the omission of algebraic details. Its physics is explored through numerically-solved examples and comparison with the analytical part of the model. The purpose is to subsidize the diagnosis of forms in which instability occur: at the ocean surface and in the interior of the water column. Additionally, the effect of the continental slope on the instability properties is investigated and discussed, through its effects on the propagation of unstable waves generated by instability process.

geophysical jets; baroclinic instability; Western Boundary Currents Brazil Current; unstable waves


Sociedade Brasileira de Geofísica Av. Rio Branco, 156, sala 2510, 20043-900 Rio de Janeiro RJ - Brazil, Tel. / Fax: (55 21) 2533-0064 - São Paulo - SP - Brazil
E-mail: sbgf@sbgf.org.br