Elevational dependency of precipitation climatology and trends in global mountains: a model view

High-altitude regions have been identified as hotspots of climate change. In particular, the dependence of warming rates on elevation, known as Elevation-Dependent Warming (EDW), has been extensively discussed in the literature. Recently, the focus has expanded to the broader concept of Elevation-Dependent Climate Change (EDCC), with attention to precipitation and its extremes, given their importance for mountain hydrological resources and their role in triggering geo-hydrological hazards. Recent studies have investigated the elevational stratification of precipitation in  in-situ observations and reanalysis datasets, showing a lack of uniform patterns of EDCC across the world, which point to the need for common methodologies and insight in the driving mechanisms. In this study, we extend results we obtained with the ERA5 reanalysis to CMIP6 global climate models, and study EDCC in key mountain regions of the world: Tibetan Plateau, the US Rocky Mountains, the Greater Alpine Region, and the Andes. We focus on precipitation and its extremes, assessing the ability of the models  to reproduce historical patterns of stratification by comparison with ERA5 reanalysis data and other observation-based gridded datasets. We also explore how the stratification in other key climate variables, such as cloud cover, humidity, besides temperature, influence the elevational patterns of precipitation and precipitation extremes and their trends. Our analysis aims to determine whether the observed elevation-dependent precipitation patterns are primarily driven by dynamical, thermodynamical, or microphysical processes, identifying seasonal variations and the specific precipitation type (i.e., stratiform vs convective)  mostly affected. Particular attention is given to the role of the model spatial resolution, including regional climate models in a case study analysis over the Greater Alpine Region.