A numerical model of tides and storm surges in the Rio de la Plata Estuary

Abstract

A numerical model (two horizontal dimensions, vertically integrated) is used to investigate tides and storm surges in the Rio de la Plata Estuary. The domain includes the Estuary and continental shelf together and extends from 33°40′S to 39°20′S latitude, and from 51°W to 59°W longitude. The bathymetry was taken from nautical charts at 5′ × 5′ intervals, so that the domain has 97 × 69 grid points. These depths vary from 1.1 m in the upper Estuary to 5000 m off the shelf. The semidiurnal lunar tide is modeled by forcing at the boundaries and the cotidal and corange lines compare well with observations. The history and description of storm surges in the Rio de la Plata are recounted, and cases are modeled for easterly and southeasterly wind stresses from 2 to 8 dynes cm −2. The resulting sea levels and currents in the estuary and shelf are discussed in terms of their dynamics, and compared with what limited information is available.