THERMAL INDEXES FOR THE IDENTIFICATION OF HEAT WAVES APPLIED TO STATE OF PARANÁ, BRAZIL.

Abstract

The purpose of this work is to analyze the variability of the maximum annual temperatures in the state of Paraná from 1976 to 2015 to identify the occurrence of periods of extreme heat. Two different indexes were applied: 1) spring - summer (P - V) and 2) daily index (ID). The P-V index allows you to detect only the most extreme events. It was found that they occur more frequently in the months of November to February. The ID index identifies the anomalous warming events that occur throughout the year. It was found that the largest records occur in the autumn and winter seasons. Analyzing both indices it was possible to discover that the stations located in the northern and western regions of Paraná, mainly those located north of the Tropic of Capricorn, presented more significant heat waves, with longer duration and with higher temperatures. On the other hand, the stations located in the center-south registered heat waves with less intensity and duration. Due to the fact that the heat waves are characterized in different ways by the applied methods, the results are dependent on the index used, so the selection of the criterion to determine the heat waves depends on the purpose of the study.

The purpose of this work is to analyze the variability of the maximum annual temperatures in the state of Paraná from 1976 to 2015 to identify the occurrence of periods of extreme heat. Two different indexes were applied: 1) spring - summer (P - V) and 2) daily index (ID). The P-V index allows you to detect only the most extreme events. It was found that they occur more frequently in the months of November to February. The ID index identifies the anomalous warming events that occur throughout the year. It was found that the largest records occur in the autumn and winter seasons. Analyzing both indices it was possible to discover that the stations located in the northern and western regions of Paraná, mainly those located north of the Tropic of Capricorn, presented more significant heat waves, with longer duration and with higher temperatures. On the other hand, the stations located in the center-south registered heat waves with less intensity and duration. Due to the fact that the heat waves are characterized in different ways by the applied methods, the results are dependent on the index used, so the selection of the criterion to determine the heat waves depends on the purpose of the study.