Evolution of salinity and temperature in Bahía Blanca estuary, Argentina.

JORGE PIERINI; JORGE MARCOVECCHIO; FRANCISCO CAMPUZANO; GERARDO PERILLO,

Perspectives on Integrated Coastal Zone Management in South America.

IST Press

Lugar: Lisboa; Año: 2008; p. 501 - 510

The main driving forces of circulation in a large number of estuaries are river flow at the head of the estuary and changes in the sea level at the mouth of the estuary, which in turn determine the distribution of water properties like salinity and temperature, as well as the distribution of any other tracer. In Bah´ıa Blanca estuary there are other forcing actions like wind stress and surface heat balance and they respond differently to these forcing actions. Bah´ıa Blanca estuary is in Argentina and the most dynamic in terms of physical and biogeochemical processes. It is a very important ecosystem in the region where it is situated due to the intense human activity in its waters and along its margins. In the last 30-40 years the estuary was studied mainly from a biological and geological point of view. There are not many studies or publications regarding the hydrology and physical processes of the estuary. Despite this fact, a prior physical processes study (Perillo et al. 1987, Piccolo and Perillo 1990) reveals some of the main features of Bah´ıa Blanca. Records of water level, current velocity, temperature and salinity properties were performed at several stations in the estuary during the last years. It was determined that the type of tide at the mouth of the estuary is semidiurnal and was observed that the astronomical tide is the main forcing driving water circulation in Bah´ıa Blanca estuary. The tidal wave propagation in the study area has the characteristics of a damped progressive wave. According to this study Bah´ıa Blanca estuary was found to be a vertically homogeneous estuary. Nevertheless, some channels may reveal characteristics of a partially mixed estuary, depending on the freshwater input.