Meteorologia: análise da circulação geral da atmosfera e a influência na navegação costa sul brasileira

Abstract

The atmospheric circulations are closed flow movements caused by the conservation of mass that restrains the general movement of the atmosphere and by the pressure and counter-attraction forces as they are observed from the surface of the Earth, which is made from a rotational reference. The application of the known Bjerknes theorem plus the mass conservation equation allows the solving of the atmospheric flow in different movement scales. Atmospheric circulation can refer to the circulation of sea and land breezes, which is a mesoscale phenomenon, or it can also refer to the average annual flow of large scale, such as the Hadley and Walker’s circulations, associated to the occurrence of the El Nino and La Nina phenomena. Thus, this paper aims to evaluate the applicability of the forecast by extrapolation method as complementary means to ensure the safe meteorological navigation on board.It can be listed as specific goals: to add suggestions to improve the efficacy of this method; to provide resources that expand the knowledge of the navigator about the weather; and to interpret and apply the weather and oceanographic data available in the publications and synoptic charts from DHN.To reach these goals, this research will present, in the weather history section, the explanation of the phenomena that occurs in the region as well as the basic meteorological and oceanographic concepts, showing their behaviors. Beyond that, the research will try to expose how the seaman should act when in adverse atmospheric conditions.Asto the methodology in use, it is composed of a bibliographic research, applied nature, experimental survey and explanatory objectives.The bibliographic research is characterized by being elaborated from previously published material, being necessary forthe theoretical base of the paper and to allow the analysis of the studied phenomena. The applied nature of the study is characterized by the knowledge generation for practical application, directed in this case to the better understanding of the maritimework environment. The experimental survey consists in evaluating the reliability and the application of the method on board. Lastly, it characterizes itself as explanatory for also demonstrating the use of the method.This study is divided into six chapters (the first five dedicated to weather history and the last to the trajectories method), excluding the introduction and the final considerations. It is included the use of the publications destined to the navigator as well as the sailing directions charts and meteorology manuals, both published and kept up to date by the Notice to Mariners of the DHN, besides basic maritime books such as “Arte Naval”, by Maurílio Fonseca, “Navegação Ciência e Arte”, by Miguens, and the synoptic charts and other information available at the DHN website.