Abstract
ERA5-Land and GPCC data (at 0.1° and 0.25° resolution, respectively) cover the Balkan Peninsula with 7,297 and 1,496 grid cells. The reanalysis datasets show a very high level of agreement with in situ measurements in Montenegro, although precipitation is underestimated in mountainous areas. In the region of about 550,000 km
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, for the period 1950–2024, ERA5-Land (GPCC) indicates decreases in seasonal and annual precipitation: in winter in 90% (64%), in spring in 80% (57%), in summer in 70% (62%), in autumn in 42% (38%), and annually in 83% (60%) of the Balkan grid cells. The proportion of territory experiencing significant reductions is relatively small, with the annual trend decreasing markedly over approximately 12% of the region. Results show that 10 out of 11 atmospheric oscillation indices have a spatially significant impact on winter precipitation, especially NAO, AO, EAWR, and NCP. In other seasons and annually, precipitation is influenced by fewer oscillations. Conversely, the effect of two anthropogenic greenhouse gas (GHG) indicators was largely insignificant and ambiguous. Correlation analyses further reveal that only in limited areas do two of five oceanic oscillations significantly influence winter and summer precipitation (AMM and AMO), while PDO affects spring precipitation variability. These findings highlight the importance for policymakers to consider changing precipitation regimes in the Balkans, regardless of cause, given water’s central role in supporting life and socio-economic development.
