Analysis of thermal discomfort associated with synoptic conditions in the city of Pelotas, extreme south of Brazil

Abstract

This study aims to evaluate the outdoor environment conditions (synoptic weather conditions) on extreme events of human thermal discomfort in the city of Pelotas, Brazil, between 18th January and 20th August, 2019. Digital thermohygrographs were installed outside the residences in order to record of air temperature data, dew point temperature and air relative humidity. Five different macro-regions of the city were analyzes applying two different biometeorological indices. For the summer months, the Humidex Index was used, and for fall and winter, the wind chill index was used. The findings showed that the afternoons during the summer months were the most thermally uncomfortable, while the nights presented the greatest sensations of comfort. In the winter months, the opposite occurred: afternoons with more comfortable periods and nights with more thermally uncomfortable periods were observed. It was also noted that in the situation of extreme heat stress, in the summer, there was the influence of the South Atlantic Subtropical Anticyclone (SASA) on the region, which, in association with the low humidity of the air on the continent, favored, then, the extreme discomfort sensations. Likewise, situations of extreme discomfort due to cold that were also associated with low air humidity, and high atmospheric pressure systems (not necessarily the SASA), which caused drops in temperature and dry air.

Expert system as a tool for management of thermal comfort in heat environments in agribusiness

“…During the early morning hours (6:00 am-9:00 am), DIK values are relatively low, indicating thermal comfort or mild heat discomfort. This behavior can be attributed to the lower ambient temperatures and higher relative humidity typical of this period, as observed by Trassante et al (2024), who reported discomfort due to lower temperatures in the early morning hours in similar studies.…”