Campos de vento e circulação oceânica no Canal de Moçambique: perspectivas a partir de diferentes estimativas

Abstract

The ocean surface circulation depends on the local or regional wind regime. Hydrodynamic models usually apply wind field, ocean currents, as well as temperature and salinity data as initial and boundaries conditions. Nowadays, there are several datasets available, which can be used for forcing regional oceanic models. However, accurate wind fields, ocean currents, temperature and salinity datasets are required, to enable the proper representation of these processes by the model. In this study, an assessment is made for three different datasets derived from scatterometers (wind), altimetry (currents) and reanalyzes (wind, currents, temperature and salinity) in the Mozambique Channel. It is found that, Mozambique Channel is dominated by semiannual and annual wind field cycles, but on a local scale there is noticeable differences in the magnitude of wind velocity between the three analyzed datasets. For instance, in the Northern region of the Mozambique Channel the estimated magnitude of wind stress is higher for CCMP and QSCAT than the ASCAT. In the central part of Mozambique Channel, the seasonal pattern of the wind stress is similar for CCMP and ASCAT while QSCAT does not show any seasonal variation, suggesting that CCMP represents better the wind field in the Mozambique Channel. For the surface current, the analyzed datasets show strong currents during the winter in the Northern and Southern limits of the Mozambique Channel but SODA and NCEP underestimate the magnitude of the current, although SODA have a better representation of the surface circulation than NCEP. The vertical profiles of temperature indicate a deeper mixed layer during the winter season for all dataset (CARS2009, SODA and NCEP), but SODA is in agreement with climatology dataset derived from CARS2009. Differences were noted on salinity vertical profiles between three datasets, mainly within the first 200-meter depth. These differences found in wind field, currents, temperature and salinity may have implications in numerical models of oceanic processes.