Along with air temperatures, the freezing level height (FLH) has risen over the last decades. The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the FLH, mainly due to a decrease in accumulation and increase of energy for ablation caused by reduced albedo. Knowledge of future changes in the FLH is thus crucial to estimating changes in glacier extents. Since in situ data are scarce at altitudes where glaciers exist (above ~4800 m above sea level (asl)), reliable FLH estimates must be derived from multiple data types. Here we assessed the FLHs and their spatiotemporal variability, as well as the related snow/rain transition in the two largest glacier-covered regions in Peru by combining data from two climate reanalysis products, Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar Bright Band data, Micro Rain Radar data, and meteorological ground stati...

Water from glaciers is crucial for the Peruvian hydropower production. Hence, we investigate the glacier-atmosphere and climate interactions in the Cordillera Vilcanota, considering scenarios of significant precipitation reductions until 2100. The glacier mass balance model ITGG-2.0 is used for analysing the energy balance components regarding the projections. The results indicate that a precipitation decrease not only affects the accumulation rate of glaciers but also influences the ablation energy availability. Therefore, glacier retreat in the Central Andes is expected to accelerate, making water availability unsustainable and likely leading to future shortages for the hydropower sector and for other water consuming systems.