Effects of climate change on Balıkesir province: Investigation of temperature extremes for the period 1975-2023

Abstract

This study aimed to analyse the changes and trends in the temperature extremes at the Ayvalık, Balıkesir, Bandırma, Burhaniye, Dursunbey, Edremit, and Gönen meteorological stations in Balıkesir province, all of which have long-term meteorological observation records. In this framework, 16 extreme temperature indices such as the maximum value of the daily maximum temperature (TXx), the minimum value of the daily minimum temperature (TNn), summer days (SU25), and tropical nights (TR20) were calculated using the daily temperature data from these stations for the 1975 to 2023 period. The temperature indices were evaluated in three main categories: degrees, days, and percentages. Trends in these extreme temperature indicators, calculated using the RClimdex package, were analysed with the Mann-Kendall trend test and slope estimate. The results indicate significant increases in the warming-related temperature indices at most stations, while the cooling-related indices generally show a decreasing trend. Over the 49-year period, the SU25 index increased by 25 days in Balıkesir and Edremit, while the TR20 index increased by 65 days in Bandırma and by 58 nights in Ayvalık. The percentage of warm nights (TN90p) increased between 5% and 19% across the stations, whereas the number of cold days (TX10p) decreased by 10% to 13%. These findings demonstrate that climate change has a substantial impact on temperature extremes in Balıkesir province, with both global climate change and urbanisation contributing to these changes.