Development and calibration of a sea-ice - climate - glacier model for Northern Iceland

Situated just south of the Arctic Circle, Iceland is the biggest land mass and the most important source of terrestrial records of environmental and climatic changes in the predominantly marine environment of the North Atlantic. Important atmospheric and oceanic boundaries such as the polar front and the southern limit of the North Atlantic sea-ice oscillate around Iceland. Thus Iceland lies in a crucial position for the understanding of the North Atlantic circulation system, which controls climatic conditions over wide parts of Europe. The ca. 250 small corrie and valley glaciers of the Tröllaskagi and Flateyjarskagi peninsulas in Northern Iceland react very rapidly to changes in temperature and precipitation, thus they provide high-resolution climate proxy data. A detailed Holocene glacier history has been established in Northern Iceland in recent years. Quantitative palaeoclimatic reconstructions on the basis of this record are however hampered by the lack of calibrated climate - glacier relationships. The climatic parameters governing glacier behaviour in Northern Iceland are highly correlated to the occurrence of sea-ice around Iceland. Therefore, the latter is an important element for the calibration of climate - glacier relationships in this area, and provides the link to the larger-scale North Atlantic atmospheric and oceanic circulation. Against this background, the aim of the proposed research project is the development and calibration of a model describing the relationships between sea-ice, temperature and precipitation conditions and glacier extents in Northern Iceland for the period since the mid 19th century, when continuous and homogeneous meteorological records in Iceland start. The available climate proxy data in Northern Iceland demonstrates that this period has shown climatic extremes which are comparable to the Holocene optima and pessima. Thus this model allows quantitative palaeoclimatic reconstructions for the Holocene before the beginning of meteorological measurements. The adopted approach of relating glacier behaviour to temperature and precipitation guarantees that the climatic parameters reconstructed by means of this model can be compared to palaeoclimatic data based on other proxy records in Northern Iceland. As an additional result of the model calibration, a GIS-based glacier inventory following the standard of the UNESCO World Glacier Inventory is established for Northern Iceland.