Assessment of the wind behavior in the northern coast of Santa Catarina

The spatial and temporal coherence of wind characteristics of coastal areas of Navegantes and Praia Grande, SC, 100 km apart each other, were assessed. Despite the relatively short distance, the oceanographic and geomorphological characteristics are different and can change the local and synoptic wind behavior, which are important for the understanding of the factors controlling the hydrodynamics and water quality of coastal environments. The comparison was performed through statistical analysis in the time and frequency domain, over a data set comprising hourly records from July to December, 1996. Both stations presented similarities regarding the north-south wind component. Therefore, quite different behavior is noticed for the east-west wind component, such as the breeze effect. The north-south wind pattern in Praia Grande is similar to the general wind regime for the Brazilian south-southwest areas, with dominance of northerly winds, and with southerly winds during the passage of cold-front systems, with small account of land-sea breeze. On the other hand, the breeze is the main factor contributing for the wind kinetics for the Navegantes area. We suggest that this differentiation is partially due to the combination of the mountain-valley circulation system of Vale do Itajaí with the breeze system, indicating a strong role of the local geomorphology on the wind regime. Additionally, it is may be possible that the sea surface temperature can also contribute, since there is a general trend of smaller temperatures southwards, though increasing the thermal gradient between the land and the sea.