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

Siiri Wickström,John J. Cassano,Marius O. Jonassen,Timo Vihma

doi:10.1029/2019jd032155

Abstract

AbstractThe 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.

Highlights

The Svalbard Archipelago and its rapidly changing climate have received a lot of attention, both scientifically and among the media in recent years
Our results suggest that sea ice explains a large part of the local variability in both 2 m temperature and precipitation
atmospheric circulation (AC) Distribution As a consequence of Svalbard's location at the periphery of the North Atlantic storm track, the vast majority of the AC types are cyclonic in all seasons (Figure 2)

Summary

Introduction

The Svalbard Archipelago and its rapidly changing climate have received a lot of attention, both scientifically and among the media in recent years. Several studies have addressed the rapid warming rates and the Svalbard temperature climatology (Førland et al, 2012; Gjelten et al, 2016; Isaksen et al, 2016; Nordli et al, 2014). Alongside these temperature changes, the frequency of extreme precipitation events has been documented to increase (Łupikasza et al, 2019; Peeters et al, 2019; Rinke et al, 2017; Serreze et al, 2015; Vikhamar‐Schuler et al, 2016). Warm winter events resulting in rain‐on‐snow (ROS) have drawn attention due to their potential consequences for the cryosphere, ecosystems, and infrastructure in SIIRI ET AL

Results

Discussion

Conclusion