Trends of maximum and minimum temperatures in Ecuador and Homogeneity evaluation during the 1961-90

Before attempting to start any climatological analysis of time series, for instance temperature during a particular period, it is very important to have access to reliable data that are free from non-climatological variables. This is of particular importance when one is dealing with climate change detection. This work analyzes firstly the homogeneity of the basic data, mean monthly maximum and minimum temperatures provided by the Meteorological and Hydrological Service of Ecuador for the Normal 1961-90, and secondly it analyzes trends and deviations from long-term means for that region of the world. The 15 longest-record climatological stations were used; most of the stations are located south of the equator line, 12 of them. All were examined first for homogeneity, mainly applying an introduced modified version (by the author) of the Alexandersson´s homogeneity test and other common practices for dealing with inhomogeneities and their adjustments. Then, the long-term means and their deviations were determined for each station. These deviations were standardized for comparisons and averaging purposes in all Ecuador. Next step was to calculate and draw the trends and analyze particular subperiods. The results show an increase of the minimum temperatures and a reduction of the daily temperature ranges in most of the stations, especially the ones located at higher altitudes. These results agree quite well with others reported elsewhere in South America, especially in Venezuela, Colombia and Bolivia all these countries analyzed previously by the author.