HISTORICAL EVOLUTION OF THE AIR TEMPERATURE IN THE CITY OF BOA VISTA – RORAIMA

EVOLUCIÓN HISTÓRICA DE LA TEMPERATURA DEL AIRE EN LA CIUDAD DE BOA VISTA - RORAIMA

Abstract

The climate has undergone significant changes since the 20th Century on a global and regional scale, and these changes are clearly evident in the dynamics of air temperature. Thermal studies carried out in the Northern Amazon are still incipient, especially when treated on a local scale. The present study aims to evaluate the dynamics of air temperature in the city of Boa Vista, Roraima, for the period from 1944 to July/2024. The methodology included the analysis of average, maximum and minimum annual, monthly and daily temperatures throughout the historical series, for the periods of climatological normals from 1961-1990 and 1991-2020 to the present period. The second stage included the analysis of thermal conditions for the periods of occurrence of El Niño and La Niña events. The results show that annual temperatures fluctuated by 3.5ºC, determining an average temperature of 28.7ºC (1944-2023), in which 93.55% of the values above the average occurred after 1991. The monthly averages indicated a positive variation of 08ºC between the periods of climatological normals (1961-1990 and 1990-2020). After the second period, an acceleration of thermal conditions was observed for the current period (2021-July/2024) with an average monthly gain of 1.7ºC. This dynamic was very evident in the calculation of the frequency of monthly temperatures and in the daily thermal performance. The El Niño and La Niña events have short-term thermal influences, with emphasis on the monthly and daily values. The first event showed a strong association with the increase in temperature, while the La Niña events show a propensity for a decrease in temperatures.