Present Temperature, Precipitation, and Rain‐on‐Snow Climate in Svalbard

• Published in: Journal of Geophysical Research: Atmospheres
• Main Authors: Wickström, Siiri, Jonassen, Marius Opsanger, Cassano, John J., Vihma, Timo Pekka
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Arctic; Svalbard; Svalbard Archipelago; Sea ice
• Online Access: https://hdl.handle.net/11250/2761478; https://doi.org/10.1029/2019JD032155

The Svalbard Archipelago has undergone rapid warming in the recent decades leading to warmer and wetter winter conditions. This study relates the present (2013–2018) 2 m temperature, precipitation, and rain-on-snow (ROS) climate in Svalbard to different atmospheric circulation (AC) types utilizing the high-resolution numerical weather prediction model Application of Research to Operations at Mesoscale (AROME)-Arctic. We find that the 2 m median temperatures vary most across AC types in winter and spring and in summer they vary the least. In all seasons the 10th percentile 2 m temperatures are above 0°C with southwesterly AC types over Svalbard. In comparison, the relationship between AC type and precipitation varies more spatially, with most accumulated precipitation and highest median precipitation intensities with onshore flow over open water. Our results suggest that sea ice explains a large part of the local variability in both 2 m temperature and precipitation. In the studied period ROS is a frequent phenomenon up to 150 m above sea level (ASL) on land, with most events in the southwestern parts of the archipelago (57 cases during five winter seasons). ROS events in winter occur predominantly with AC types from the southerly sector or during a low-pressure center/trough passage. The southwesterly cyclonic AC type, with a low-pressure center west of Svalbard, is the most frequent AC type for ROS events. In addition to being the most frequent, the southwesterly AC has the largest spatial coverage of ROS. publishedVersion