Climate Change and Precipitation Variability Influence on the Greenland Ice Sheet

Abstract: Climate changes have a large impact on precipitation patterns and precipitation variability change. With this in mind, precipitation over Greenland is studied. This is done for present day precipitation model data from 1991-2010 compared to future model simulations of precipitation for 2081-2100. Furthermore, precipitation drives Surface Mass Balance (SMB), which is the sum of accumulation and the loss of mass by melting of the ice sheet, meaning it decides the evolution of glaciers. In order to find more information about future changes of precipitation distribution between the seasons of the year and possible changes, precipitation variability is investigated. Also, the aim includes an examination of the difference in mean annual precipitation between the time periods. Model simulations with EC-Earth downscaled through HIRHAM5 is mainly used for this study. Also the global atmospheric re-analysis ERA-Interim is used and a new model with modified ice sheet topography called GT2. There will be an increase in mean annual precipitation over Greenland for 2081-2100 compared to 1991-2010, a conclusion made according to the results obtained using RCP8.5, a scenario with high rates of combustion. The SMB mass term will with this scenario, become more negative in the future compared to present day, meaning there will be a greater mass loss of the Greenland ice sheet. In the final analysis, the precipitation variability as well as the seasonality will change for Greenland in the future according to the RCP8.5 scenario.