Características hidrodinâmicas da plataforma interna do nordeste paraense

Abstract

This study aims to characterize the hydrodynamics of the continental shelf near the northeast coast of Pará state of in adjacent points to the municipalities of Salinópolis and Marapanim. The choice of the period of data acquisition took into account the contribution of the Tocantins River, which has a higher discharge during the month of April and lower discharge during September. Data were collected at two anchored stations on September 11, 2013 and April 25, 2014, both of 25 hours duration. Each as obtained data were not only hydrodynamic (longitudinal component of current) and hydrographic data (temperature, salinity and density), it was possible to calculate the transport of mass and volume. The observations were performed using a couple of acoustic Doppler current profilers and salinity, temperature and pressure data recorders. The data processing included filtering by moving averages and interpolation to analyze the results in dimensionless depth. The hydrographic results revealed a possible influence of continental drainage during the acquisition period. The comparison between water currents and wind during the experiments showed that the influence of the wind was not relevant in the circulation. The transport calculations indicate a circulation predominantly influenced by tide and freshwater contributions.