Dynamic issues in the SE South America storm surge modeling

Abstract

The southeastern coast of South America is located in one of the most cyclogenetic areas in the Southern Hemisphere. Occasionally, those systems may lead to disastrous flooding. Strong and persistent along-shore winds on the shelf may also result in some coastal flooding of smaller magnitude. Nested depth-averaged numerical models are used for the simulation of the storm surge. This study describes the storm surge dynamics in the area and the consequences of different regimes to the storm surge prediction. The large extension and limited depth of the Argentinean Shelf permits a smooth transition of the storm surge to the Rio de la Plata and a relatively long forecast horizon for its innermost zone. On the other hand, it is demonstrated that currents in the navigable channels of the Bahia Blanca estuary are the main cause for a strong tide–surge interaction. There, the relative phase between the meteorological forcing and the tide can shift the peak of the storm surge several hours.