Importance of large scale extreme precipitation to the surface mass balance of the Greenland Ice sheet

• Main Author: Hallberg, Moa
• Format: Other/Unknown Material
• Language: English
• Published: Lunds universitet/Förbränningsfysik 2018
• Subjects: Ice sheet; Greenland; surface mass balance; atmospheric rivers; Physics and Astronomy; Ice Sheet
• Online Access: http://lup.lub.lu.se/student-papers/record/8951640

The ongoing climate change has affected Greenland's ice sheet with heighten near surface temperatures, an extended melt season and change in precipitation. These effects have caused Greenland's ice sheet to melt at an accelerating rate. This study focuses on the importance of large scale extreme precipitation to the surface mass balance of Greenland. The surface mass balance of Greenland's ice sheet is the difference between the accumulation and ablation. The large scale extreme precipitation in this study is mainly focused on the precipitation brought to Greenland by atmospheric rivers. An atmospheric river is a weather phenomenon were a large amount of water is being transfered over large distances in the atmosphere. The precipitation and surface mass balance data is calculated by HIRHAM5 and the atmospheric river data retrieved from ERA-Interim AR detection catalog. How the surface mass balance is affected by atmospheric rivers depends to a large extent on the season. The result showed that an atmospheric river occurring during the summer season most likely will negatively affect the surface mass balance, as the one occurring in 2012 did, while atmospheric rivers occurring during the winter usually has a positive influence, as seen in 1996. During the summer season a decreasing trend in the surface mass balance can seen due to the increasing near surface temperatures and the extended melt season. The west coast of Greenland is the most affected by atmospheric rivers, since the main precipitation brought to the west coast of Greenland is by atmospheric rivers even if the east coast experience a higher amount of daily precipitation.