How tropical cyclones drive extreme positive glacier mass balance in the central–eastern Himalayas

Abstract. Extreme climate events are increasingly recognized as important drivers of glacier change. Although tropical cyclones (TCs) are a type of extreme weather event, their impacts on glacier mass balance and the associated physical processes remain poorly understood. This study used more than 10 years of in situ observational data and an energy–mass balance model to reconstruct the energy and mass balance of Naimona’nyi Glacier over 2000–2024, and analyzed the impacts of TC Tauktae on glacier mass balance and associated physical mechanisms in May 2021. During May 18–21, 2021, meteorological and energy conditions changed markedly. Precipitation reached its highest level for the same period since 2000 and occurred almost entirely as snowfall, enhancing mass accumulation and surface albedo. Meanwhile, increased cloud cover reduced incoming shortwave radiation, and higher relative humidity decreased latent heat flux. These variations reduced melt energy, suppressed melt and sublimation, and increased mass accumulation, resulting in an extreme positive glacier mass balance for four consecutive days. Regional analysis shows that the associated meteorological and energy anomalies extended across the central and eastern Himalayas. This study reveals the physical mechanisms through which TCs drive glacier change on the Tibetan Plateau from an energy-balance perspective, filling a research gap in this area and providing important insights for regional glacier assessment and future projections.