Análise de brisas utilizando a teoria termodinâmica de circulações convectivas.

Abstract

Sea breeze is generated due to the ocean surface being less heated than the land surface, causing the circulation of winds from the less heated region to the more heated region, that is, from the ocean surface towards the land surface, during the day. On the other hand, the land breeze occurs basically inversely, during the night, when the land surface is less heated than the ocean, generating circulations that go from the land to the ocean. Although it appears that one is the opposite of the other, there are differences, as the land breeze occurs with less intensity than the sea breeze, because at night the thermodynamic forcing is weaker. In this research, the thermodynamic theory of convective circulation was used to compare its results with the reanalysis data obtained from ERA5, which are reanalysis times with a spatial resolution of ~28 km. The analysis period covered the entire year of 2018. This made it possible to analyze the temperature difference between the ocean and land, the thermodynamic efficiency of the system and the difference in atmospheric pressure, with the aim of verifying the veracity of the thermodynamic theory of convective circulation and analyze, through this theory and reanalysis data, the circulation of sea and land breezes on the coast of Ceará. For this, a point A and a B were used as reference, one located in the ocean and the other on the earth's surface, respectively. Furthermore, to obtain the results, a fixed gamma value of 0.26 was initially applied. Although it provided satisfactory results, this gamma value was varied monthly to improve results, as its variation influences dissipation near the surface. Based on the analyses, the results reveal that the theory provides a good basis for understanding and predicting breeze circulation patterns, demonstrating good agreement with observed data, especially in the case of sea breezes. It was also observed that the difference in temperature between the ocean and land directly interferes with the observation of breezes, in which the rainy months have lower temperature values, which makes it difficult to observe breezes.