ABSTRACT Precipitation concentration is a key indicator for characterising spatio‐temporal heterogeneity of precipitation and assessing hydrological responses to climate change. Nevertheless, most existing studies have concentrated on total precipitation, neglecting how different precipitation phases (rainfall and snowfall) exhibit distinct concentration patterns and sensitivities to climatic forcing. This omission has limited understanding of hydro‐climatic processes in high‐altitude regions, where shift of precipitation from solid to liquid (SPSL) strongly modulates water resources and extreme events. Addressing this gap is challenging in the Asian Water Tower (AWT), given extreme topographic complexity, sparse observations, and strong influence of multiple circulation systems. Using ERA5‐Land reanalysis data at approximately 10 km (0.1°) spatial resolution (1980–2023), combined with a validated precipitation phase discrimination method, we investigate phase‐specific precipitation concentration indicators across the AWT. This study provides one of the first region‐wide, phase‐resolved assessments of precipitation concentration in the AWT by jointly quantifying rainfall and snowfall. It further examines their contrasting elevation‐dependent behaviours, extending previous work that focused solely on total precipitation concentration. Rainfall was strongly clustered in summer and exhibited relatively stable trends, whereas snowfall peaked in late winter–spring. Notably, snowfall concentration diverged by elevation, with increasing concentration at lower elevations but decreasing concentration at higher elevations, highlighting phase‐specific sensitivity to warming. Modulation of precipitation concentration by large‐scale circulations was evident. Indices such as ENSO and Indian Summer Monsoon Index (ISMI) significantly influenced seasonal concentration. El Niño conditions were associated with more temporally dispersed rainfall, whereas La Niña conditions enhanced clustering in southern AWT. In contrast, snowfall concentration index (SCI) was positively influenced by cold‐air outbreaks linked to Siberian High and mid‐latitude westerlies. By explicitly contrasting rainfall and snowfall concentration, this study advances beyond previous total‐precipitation analyses and demonstrates a new pathway to identify hydrological instability in alpine regions. Findings advance understanding of precipitation phase dynamics in high‐altitude regions and offer implications for disaster early warning, seasonal water allocation, and climate‐resilient reservoir management in snow‐dominated basins.
Tang et al. (Thu,) studied this question.