Air temperature trend analysis of Târgu Mureș, Romania, between 1986-2020

Abstract

One of the processes with the greatest impact on humanity in the second half of the twentieth century was global warming. Detection, estimation and prediction of trends are important aspects of climate research (Hansen and Lebedeff, 1987). Trends have become the most frequently used technique to identify climatic variability on a regional and local basis (Amadi et. al., 2014). Trend is a long-term change (increase or decrease) in a time series (Ragatoa, 2018). In the current context of climate change, we considered that a study on the evolution of air temperature in the last 35 years is needed, especially since it is the first study of its kind for this area. The aim of this study was to highlight long-term trends (magnitude and direction) in terms of air temperature (average, minimum, maximum, anomalies), at different time scales (multiannual, seasonal and monthly), in the city of Târgu Mureș, between 1986-2020. The analyzed data series come from the archive of the National Meteorological Administration with the records made by the local meteorological station. The analysis was performed using MS Excel spreadsheets with MAKESENS software to evaluate trend and data distribution (Mann-Kendall, Sen's slope, Kurtosis and Skewness). According to the results of the Mann-Kendall test and the estimation of the slope of Sen, there were statistically significant positive trends in the warmer months (June, July and August). Average temperature values increased by up to 1.6° C, and the average slope varied by 0.049° C / 35 years. Regarding the multiannual average, with one exception (2011), the last 13 years have shown positive trends. Consequently, the average annual temperature in Târgu Mureș shows obvious growth trends in the last 35 years.