Understanding climate change projections for precipitation over western Europe with a weather typing approach

摘要: Precipitation over western Europe (WE) is projected to increase (decrease) roughly northward (equatorward) of 50°N during the 21st century. These changes are generally attributed alterations in regional large-scale circulation, e.g., jet stream, cyclone activity, and blocking frequencies. A novel weather typing within sector (30°W–10°E, 25–70°N) used for a more comprehensive dynamical interpretation precipitation changes. k-means clustering on daily mean sea level pressure was undertaken ERA-Interim reanalysis (1979–2014). Eight types identified: S1, S2, S3 (summertime types), W1, W2, W3 (wintertime B1, B2 (blocking-like types). Their distinctive characteristics allow identifying main precipitation-driving mechanisms. Simulations with 22 Coupled Model Intercomparison Project 5 models recent climate conditions show biases reproducing observed seasonality types. In particular, an overestimation type frequencies associated zonal airflow identified. Considering projections following (Representative Concentration Pathways) RCP8.5 scenario 2071–2100, three driest (S1, B2, W3) (mainly +4%) detriment rainiest types, particularly W1 (−3%). explain most WE. However, type-independent background signal identified (increase/decrease northern/southern WE), suggesting modifications precipitation-generating processes and/or model inability accurately simulate these processes. Despite caveats scenarios WE, which must be duly taken into account, our approach permits better understanding trends