Використання інформації відкритих баз метеоданих у дослідженнях новітніх кліматичних змін в західному регіоні України

Abstract

Studies of the regional manifestations of recent climate changes have a big practical importance for different scientific fields and applied purposes. Open databases of historical weather conditions can serve as a valuable source of information on recent climate changes for Ukrainian scientists with limited funds available. These data can be preprocessed, analyzed and plotted with open-source data processing software. ECAD and GHCN datasets have a plenty of uploadable weather data that can be processed with the free R software environment. ECAD has data for 39 Ukrainian weather stations, while GHCN database contains temperature and precipitation data for 190 Ukrainian weather stations, although with variable time span and completeness. Preprocessing of these data in R may involve creating special scripts to automatize and speed up the work. The data on daily temperatures and precipitation sums for three weather stations in Western Ukraine (Lviv, Chernivtsi, and Uzhhorod) were uploaded from GHCN dataset for the common period of 1960 – 2014 yrs. The completeness of temperature data was significantly higher (less than 0.16% dates omitted) than that of precipitation data (11 – 12% dates omitted). The date field was split to three separate fields for year, month and day, and weather data were summarized to obtain yearly average temperatures and precipitation sums. In addition, separate temperature averages and precipitation sums were calculated for each of four seasons by filtering data with appropriate month numbers. Linear and quadratic models were built on derived time series to detect possible trends. Coefficients of determination were calculated and analyzed for significance for linear and quadratic models. For significant linear trends, regression coefficients were calculated which characterize the rate of change average for the time period, while in case of significant quadratic trends theirs directions were determined. It was established that while average annual temperatures have significantly increased in each of the three analyzed locations, this increase was nearly twice as large in Chernivtsi than that in Uzhhorod. In Lviv, temperatures have increased the most in spring and winter, while in other two locations the summer increase was the largest. Summer temperatures were increasing with acceleration, which can be a warning sign. Autumn was the only season when temperatures did not increase significantly in any of the analyzed locations. Trends in precipitation amounts were much less salient: precipitation somewhat decreased in Chernivtsi in winter and spring, and somewhat increased in Lviv in spring.