Elevation Dependence of Rainfall and Snowfall in Global Mountains: Insights From Reanalysis and Convection‐Permitting Models

Abstract

Mountain precipitation varies systematically with elevation—a relationship known as the elevation dependence of precipitation. This dependence governs hydrological partitioning and ecosystem stability in high‐mountain regions worldwide. However, the elevation dependence of precipitation and its underlying physical drivers across global high‐mountain regions remain poorly understood. Here, we use reanalysis data sets and convection‐permitting models (CPMs) to elucidate elevation‐dependent precipitation characteristics across four major high‐mountain regions, including the Tibetan Plateau, the North American Cordillera, the Andes, and the Alps. Our results reveal that along windward slopes across all four regions, precipitation increases with elevation, reaches a maximum at intermediate elevations, and then decreases. Regionally, the precipitation maxima over the Tibetan Plateau and the North American Cordillera are mainly controlled by the topographic contribution, whereas those over the subtropical Andes and the Alps are primarily governed by wind convergence. By contrast, in non‐windward regions, precipitation increases consistently with elevation. Regarding the precipitation phase, snowfall increases with elevation across most areas of the four mountain regions, driven by phase transitions and enhanced precipitation efficiency that together outweigh reduced moisture supply at high altitudes. Rainfall shows similar elevation dependence to total precipitation, but reaches its maximum at lower elevations on windward slopes, reflecting a transition from rainfall to snowfall. CPMs capture these features well, resolving finer vertical precipitation structures over windward slopes and showing stronger elevation dependence in non‐windward regions, with the physical processes responsible for the stronger elevation dependence in ICON varying regionally. These findings improve our understanding of the relationship between topography and precipitation and have important implications for water‐resource management and climate adaptation in mountainous regions worldwide.