This study investigates the relationship between teleconnection patterns and the frequency and intensity of daily extreme precipitation across Turkey. Using the high-resolution ERA5-Land daily precipitation dataset for the period 1950–2023, indices for extreme precipitation frequency (R95N, R99N) and precipitation total from these events (R95AM, R99AM) were calculated. A Pearson correlation and Empirical Orthogonal Function (EOF) analysis was then performed between these indices and the prominent teleconnection patterns North Atlantic Oscillation (NAO), Arctic Oscillation (AO), North Sea-Caspian Pattern (NCP), and Eastern Atlantic Pattern (EA) on annual and seasonal timescales. The results indicate that the NAO is the dominant influence, explaining more than 30% of the variance in the annual frequency of daily extreme precipitation, with statistically significant correlations covering 33% (16%) of Turkey for R95N (R99N). A negative NAO phase correlates significantly with an increased frequency and amount of extreme precipitation events, particularly in western Turkey during (17% of area for R95N) and autumn (15% for R95N). The AO is the second most influential pattern, showing significant correlations in both winter (~ 17% of area for R95N/R95AM) and summer (~ 20–24% for all indices, especially in Central Anatolia). In contrast, the impacts of the NCP and EA are weaker and more seasonally constrained, with NCP showing maximum influence in summer (17% for R95N) and EA primarily affecting spring precipitation (16–20% for R95N/R95AM). The influence of all teleconnections is strongest in winter and exhibits clear regional differentiation, wherein western, Mediterranean-influenced regions are most sensitive. These findings confirm that atmospheric teleconnections are a fundamental control on the occurrence of daily precipitation extremes in Turkey. Using a comprehensive spatial dataset (8055 grid cells at 0.1° resolution) and combining correlation analysis with EOF decomposition, this study provides the first systematic assessment of how four major teleconnection patterns simultaneously influence daily extreme precipitation indices across Turkey. These findings provide valuable information for determining risk management strategies, improving preparedness for disasters caused by extreme precipitation, and developing climate change adaptation strategies, especially in the regions most vulnerable to daily extreme precipitation events in Turkey.
Güler et al. (Sun,) studied this question.