Spatial and Temporal Planetary Boundary Layer Moisture‐Source Variability of Crimean Peninsula Precipitation

The atmospheric water cycle is a key component of the global energy and moisture exchange. In order to gain better understanding of the atmospheric processes and temporal variability and trends affecting precipitation in Crimea, we use a Lagrangian moisture source detection technique based on reanalysis data from the European Center for Medium‐Range Weather Forecasts. The study presents a quantitative picture of the major moisture sources that feed precipitation on the Crimean peninsula from February 1979 to January 2017. In total 51.3% of moisture stems from marine sources. Specifically, the main individual contributors are the Mediterranean Sea (15.3%), the Black Sea (14.4%), and the North Atlantic Ocean (13.9%). Continental moisture recycling contributes additional 46.9%. The amounts of moisture contribution from marine and continental sources and their respective moisture transport pathways are subject to strong seasonality. Winter precipitation in Crimea is predominantly sourced by the Mediterranean Sea. Long‐term temporal trends in contribution from any of the major moisture sources are absent during the study period. Statistically significant negative correlation between the North Atlantic Oscillation (NAO) index and contribution from moisture sources exists in winter for the Mediterranean (R = −0.22) and Black Seas (R = −0.23), and for the southern continental moisture source (R = −0.37). The North Atlantic Ocean moisture source exhibits a statistically significant positive correlation with NAO index during spring (R = 0.32).Plain Language Summary: The atmospheric water cycle is a component of the global water cycle. It describes the behavior of water in the atmosphere from the evaporation in the source region to the final precipitation. This study presents a comprehensive picture of the precipitation water sources for the Crimean peninsula from 1979 to 2017. Additionally, trajectories allow to estimate travel times and pathways of air parcels. Approximately half of the Crimean precipitation originates in the marine sources: the Mediterranean Sea, Black Sea, and the North Atlantic Ocean. The other half derives from moisture recycling on the continent. Contributions from different sources vary seasonally. Despite considerable variability, there are no apparent long‐term trends in contributions from any precipitation source over the 38 years period. Sources are sensitive to the North Atlantic Oscillation index, particularly during winter.Key Points: Sources of precipitation for the Crimean peninsula in the Black Sea were identified using a Lagrangian approach. The main moisture sources are Mediterranean Sea, Black Sea, and Atlantic Ocean, as well as the continental landmass via moisture recycling. Variability in winter is partly related to the North Atlantic Oscillation. No significant temporal trends were detected over the study period.German Research Foundation (DFG)Humboldt‐Universität zu Berli