Variabilidade espaço-temporal do Índice Humidex sobre a região Nordeste do Brasil

Abstract

Thermal comfort, Humidex, is a very important variable to assess the degree of thermal stress on living beings. Because it depends on climatic variables, Humidex has a space-timeintensity variation conditioned to various weather and climate attenuators. Thus, the objective of this work is to verify possible trends and spatio-temporal analysis of the Humidex index on the Northeast of Brazil (NEB). ERA5 data distributed by ECMWF was used for the period from 1990 to 2019. It was found that the MATOPIBA region was the one that stood out the most with positive discomfort trends over NEB, as well as the region with the largest Humidex indexes. While on the NEB coast there were low Humidex valleys which may be associated with oceanic influence. It was observed that the night time has a positive trend on NEB, especially on MATOPIBA. In addition to the hourly scale, it was also found that on the monthly, seasonal and annual scale, this region of MATOPIBA has a highlight. This is due to the fact that the replacement of the natural forest by agricultural production, in which, it directly affects the energy balance in this region. It was found that in the La Niña period it was considered relatively more comfortable thermally, whereas in the El Niño period it was reversed. The reduction and increase in precipitation on the NEB due to El Niño and La Niña led to the attenuation of the Humidex index. Therefore, the Humidex index was studied and the attenuation of this index in relation to the time-spatial scale was altered due to meteorological systems, change due to the modification of land use and attenuation due to the El Niño and La Niña phenomena.