Variability and trends in record air temperature events of Turkey and their associations with atmospheric oscillations and anomalous circulation patterns

• Published in: International Journal of Climatology
• Main Authors: Türkeş M., Erlat E.
• Other Authors: Ege Üniversitesi
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley and Sons Ltd 2018
• Subjects: 20th century reanalysis data; air mass; atmospheric standard pressure levels; heat waves; Mediterranean Basin; potential temperature; vectoral and meridional winds; Arctic; North Atlantic; North Atlantic oscillation
• Online Access: https://hdl.handle.net/11454/15861; https://doi.org/10.1002/joc.5720

The study investigated temporal variations of record and absolute maximum and minimum air temperatures (Tmax and Tmin, 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 Tmin events revealed an evident decreasing since mid-1980s while frequency of Tmax events increased particularly starting from the year of 2000. Half of record Tmax events were recorded during 2000–2015 period. On the other hand, daily absolute Tmax occurred mostly in 2000, whereas daily absolute Tmin 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 Tmax events and the North Atlantic Oscillation Index (NAOI) in July, December, and annually, and between the Arctic Oscillation Index (AOI) and the record Tmax events in winter months. The North Sea–Caspian Pattern Index (NCPI) had a significantly strong negative relationship with record-breaking Tmax events in February, March, August, October, and annually. However, statistically significant relationships found between the NCPI and record Tmin 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 record-breaking Tmax 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 Tmin 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. © 2018 Royal Meteorological Society The authors are grateful the NOAA/OAR/ESRL/PSD (Boulder, CO) for providing us ?the 20th Century Reanalysis V2 data? at ?http://www.esrl.noaa.gov/psd/data/20thC_Rean/ and http://www.esrl.noaa.gov/psd/data/gridded/data.20thC_ReanV2.html?, and the Turkish Meteorological Service for providing us ?absolute and annual record Tmax and Tmin air temperature data.? --