Melt Trends Over the Arctic Over the Last Millenium Estimated by Climate Models

• Main Author: Rumyantseva, Nadiya V.
• Format: Thesis
• Language: unknown
• Published: 2011
• Subjects: Arctic; Greenland; Ice Sheet
• Online Access: https://oceanrep.geomar.de/id/eprint/28336/

The Surface Melt estimations and Northern Hemisphere plays an important role in climate changing studies. Melting of Greenland ice sheet can results in significant sea level rise n the future. That is why it is necessary to investigate how does it went in the past. Our goal was to estimate surface melt trends in Arctic during the last millenium. In order to reach it we handled to a 1200-year long record of simulated temperature data provided by community Simulations of Last Millenium. In the frame if Last Millenium run project these data were simulated with the Max-Planck Institute for Meteorology Earth System Model. A dataset of surface temperatures at 2 meter for years 800-2005 AD with the spatial resulution of (grid cells of 3,75°lon , 3,71°lat) and temporal resolution of 6 hours was produced in Linux using CDO, NCO, GMT and Ferret. The study was focused on Greenland area as the largest ice sheet in NH. To estimate surface melt, Positive Degree-Days (PDD (°C days)) indices were calculated. PDD trends wer estimated, mapped and plotted for several locations in Greenland for millenial, centennial and decimal time scales. In order to validate the simulated data, a 10-year record was compared with the one from AWS Humboldt provided be Greenland Climate Network GC-Net. The correlation was estimated as well as temperature sets were plotted as graphs and analyzed. Finally, to check how adequately the model temperature simulation is, temperatures for several years through the millenium were plotted as graphs for the different location in Greenland. That figured out the pecularities of a certain model behavior, which make difficulties for provide surface melt estimations. According to these pecularities we discussed our results and made an assumption, for which locations in Greenland our trends estimations are realistic.