Drivers of the Extreme Early Spring Glacier Melt of 2022 on the Central Tibetan Plateau.

Extreme glacier melt has important implications for climate change studies and glacier‐related hazards. Few attempts have been made to study the characteristics and mechanisms of extreme melt on the Tibetan Plateau (TP) and surroundings, one of the largest concentrations of glaciers beyond the polar regions. To address this gap, we investigated the magnitude and possible drivers of anomalous early spring glacier melt in 2022 on the central TP using multi‐source observations (October 2020–July 2022) of Kuoqionggangri and Sangqu glaciers and an energy and mass balance model. Our results show that anomalous melt of both glaciers occurred in early spring (18 March–10 April 2022), when glaciers are traditionally expected to be frozen. There were 89 cumulative hours with air temperatures above 0°C, with a positive cumulative air temperature of 121.80°C hour at 5,700 m on Kuoqionggangri Glacier. The glacier‐wide cumulative melts on Kuoqionggangri and Sangqu glaciers from 18 March to 10 April 2022 were 22 ± 14.2 and 48 ± 37.5 mm w.e., respectively. Such anomalous glacier melt was driven by high incoming shortwave radiation and sensible heat flux, which were influenced by low cloud fraction and precipitation, and high air temperature during early spring. The weakening and northward‐shift of the westerlies, coupled with descending air motions over the central TP, reduced cloud fraction and hindered the transport of cold, moist air to the central TP. These changes occurred both in the central TP and the Himalaya, indicating the influence of macroscale atmospheric circulation patterns on this extreme glacier melt. Plain Language Summary: The Tibetan Plateau (TP) and surroundings have the largest amount of ice outside of the Arctic and Antarctic. Extreme glacier melt not only accelerates glacier mass loss, but is also important for changing climates and triggering glacier‐related disasters. Here, results show that extreme weather conditions and anomalous glacier melt occurred in early spring 2022 on the central TP. High air temperature, low cloud fraction and precipitation were the main characteristics of extreme weather events. Accompanying this extreme event, anomalously high incoming shortwave radiation and sensible heat flux control extreme glacier melt. We found that extreme weather conditions occurred in both the central TP and the northern foothills of the Himalaya. Our results indicate that extreme weather events and glacier melt were linked to large‐scale atmospheric circulation and regional climate conditions. This study contributes to a deeper insight into the characteristics and processes of glacier melt. In the future, more efforts are needed to monitor glacier melt and identify the causes of extreme glacier melt on the TP, which holds significant scientific and practical importance. Key Points: Extreme weather conditions and glacier melt occurred in the early spring of 2022 on central Tibetan PlateauExtreme glacier melt was driven by anomalously high incoming shortwave radiation and sensible heat fluxA strong northward shift of westerly winds in early spring 2022 led to extreme weather conditions and glacier melt [ABSTRACT FROM AUTHOR]