Significant climatic differences in the period 1991-2020 and analysis of its representativeness for climatic characterization in the Center Region of Jalisco

Abstract

The objective of the current research was to compare statistically on a monthly and annual scale, the climatologies 1961-1990 and1991-2020 in the Central Region of Jalisco, in order to determine (in case there are) differences between both climatologies and thatway be able to conclude on the adequate data period to characterize the current climatology of the region. Climatic informationfrom six meteorological stations with data for the period 1961-2020 was analyzed, which was divided into the sub-periods 1961-1990 and 1991-2020, and then carried out a comparative statistical analysis that included a data normality test, correlation analysis,and Tukey HSD test. The results of the correlation analysis but also the Tukey tests, show the presence of numerous evidence thatthe climate has changed during the last 30 years both on a monthly and annual scale and in diverse areas of the Central Region. Theannual mean maximum and minimum temperatures are changing significantly over the years. The changes found in the regionalclimate patterns are more evident in the temperature regime than in the precipitation regime, since in more than 61% of the monthlydata of mean maximum temperature and more than 55% of the monthly data of mean minimum temperature, a significant changewas found in the 1991-2020 climatology. According to the results, the current climatology in the study region must be characterizedby a time series of the last three decades or one that does not go beyond the first years of the 1980s, a period of time in whichclimate change began to manifest itself evidently. For that reason, the suggested options are the period 1991-2020 or 1985-2020.Climate series older than 40 years can be used to characterize extreme or irregular climatic events, and their return periods.