资源环境科技发展态势分析平台

The study investigated temporal variations of record and absolute maximum and minimum air temperatures (T-max and T-min, respectively), and surface and upper atmospheric conditions in years, in which the highest number of events were observed at 90 stations of Turkey during period of 1950-2015. The results have shown that annual frequency of record T-min events revealed an evident decreasing since mid-1980s while frequency of T-max events increased particularly starting from the year of 2000. Half of record T-max events were recorded during 2000-2015 period. On the other hand, daily absolute T-max occurred mostly in 2000, whereas daily absolute T-min events were mostly recorded in 1953.

With respect to linkages to atmospheric teleconnection patterns, statistically significant negative relationships were detected between numbers of Turkey's record T-max events and the North Atlantic Oscillation Index (NAOI) in July, December, and annually, and between the Arctic Oscillation Index (AOI) and the record T-max events in winter months. The North Sea-Caspian Pattern Index (NCPI)had a significantly strong negative relationship with record-breaking T-max events in February, March, August, October, and annually. However, statistically significant relationships found between the NCPI and record T-min events in November, January, and annually are different from other atmospheric oscillations.

Well-defined synoptic-scale surface and upper atmospheric circulation anomalies closely controlled occurrence and nature/magnitude of highest number of recordbreaking T-max events in Turkey by carrying frequently the tropical origin weather systems and continental tropical warm/hot air masses towards Turkey and her surroundings. On the other hands, record-breaking T-min events detected were related closely with the patterns of surface and upper atmospheric circulation anomalies carrying frequently polar and subpolar or mid-latitudinal weather systems with the continental polar air masses mostly cold and stable to Turkey and her surrounding regions.