Record-breaking rain falls at Greenland summit controlled by warm moist-air intrusion

• Published in: Environmental Research Letters
• Main Authors: Xu, Min, Yang, Qinghua, Hu, Xiaoming, Liang, Kaixin, Vihma, Timo
• Other Authors: National Natural Science Foundation of China, Guangdong Basic and Applied Basic Research Foundation, Research Funds for the Central Universities, Academy of Finland, European Centre for Medium-Range Weather Forecasts, NOAA’s Air Resources Laboratory, Polar Prediction Project, World Meteorological Organization
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: IOP Publishing 2022
• Subjects: Greenland; Ice Sheet
• Online Access: http://dx.doi.org/10.1088/1748-9326/ac60d8; https://iopscience.iop.org/article/10.1088/1748-9326/ac60d8; https://iopscience.iop.org/article/10.1088/1748-9326/ac60d8/pdf

Abstract On 14 August 2021, rain fell on the peak of Greenland for the first time on record. The atmospheric circulation and water vapour transport responsible for the rain were investigated. A high-pressure ridge favoured southwesterly advection of warm and moist air, the intrusion of which contributed to the rainfall. At the same time, Summit station observed above-freezing temperatures, which was the third time in a decade, after summers 2012 and 2019. The previous two warm events also included influxes of moisture, but no rainfall. Comparison between them and the 2021 event show different atmospheric pressure fields and water vapour transports. In 2021, the moisture from the southwest ascended the sloping ice sheet, whereas in the prior events moisture was transported from the southeast in smaller amounts. The sufficient supply of warm and moist air was the key factor in the 2021 rain event.