CHANGES IN FREQUENCY, PERSISTENCE AND INTENSITY OF EXTREME HIGH-TEMPERATURE EVENTS IN THE ROMANIAN PLAIN
DRAGOTĂ CARMEN-SOFIA, HAVRIŞ LOREDANA-ELENA
ABSTRACT. – Changes in frequency, persistence and intensity of extreme high-temperature events in the Romanian Plain. Recent summer heat waves (2003, 2010) had a strong socio-economic impact in different parts of the continent by means of crop shortfalls and forest fires. Sustained hot days became more frequent in the recent decades in many European regions, affecting human health and leading to additional deaths. This signal has been outlined in many studies conducted in Romania, suggesting that the southern region of Romania is particularly subject to large temperature increase. This work investigates the changing annual and seasonal heat waves at regional scale of the Romanian Plain, over period 1961-2014. Daily maximum temperature recorded at six weather stations available from the ECA&D project (European Climate Assessment and Datasets) were analyzed. The changes in the seasonal frequency, duration and intensity of heat waves were studied using the Mann-Kendall nonparametric trend test, as recommended by the scientific expert team on climate change detection. The likelyhood of higher maximum temperatures rise, particularly after the mid 1980s, and the changes in the upper tail of the probability density functions of these temperatures, within the extreme domain (beyond the 95% percentile level), explain the persistence and intensity of heat waves. The upward trends are dominant most of the year, and many of the calculated decadal slopes were found statistically significant (relative to the 5% level), proving an ongoing and strong warming all over the region. Our findings are in good agreement with several recent studies carried out at European and national scale and pledge for further scientific analyses i.e. heat stress impact on public health and agriculture.
Keywords: heat waves, 95% percentile level, frequency, persistence, intensity, Romanian Plain region.