Estimativas da Topografia do Nível Médio do Mar na costa brasileira por meio da Altimetria por Satélites

Estimates of Average Mean Dynamic Topography on the Brazilian coast using Satellite Altimetry

Abstract

The present study aims to obtain the Mean Dynamic Topography (MDT) values generated from satellite altimetry products, through the Sentinel-6A, CryoSat-2 missions and data from Global Ocean Gridded L4 Sea Surface Heights and Derived Variables. MDT variations were estimated for four tide gauge stations belonging to the Permanent Tidal Network for Geodesy (RMPG), maintained by the Brazilian Institute of Geography and Statistics (IBGE). These stations are located along the Brazilian coast in Fortaleza-CE, Salvador-BA, Macaé-RJ and Imbituba-SC. The BRAT version 4.2.1 software was used to extract the geophysical parameters of Sea Level Anomaly (SLA) and Absolute Dynamic Topography (ADT), and, from this, the MDT was estimated for the four tide stations. Finally, it was possible to obtain the monthly variations for the Sentinel-6A, CryoSat-2 missions and the multi-mission altimetry. These results were compared with each other by calculating the discrepancy and based on descriptive statistics criteria. The results demonstrate the high potential of the Sentinel-6A altimetric mission, since the discrepancy obtained between the Sentinel-6A and CryoSat-2 missions were smaller when compared to the CryoSat-2 mission and the multimission solution.

Keywords: Synthetic Aperture Radar, Satellite Altimetry, Altimetry Missions.