Abstract

Nioghalfjerdsforden (also known as 79°N glacier after its location) is a tidal-outlet glacier with an 80km long floating tongue, in the northeast of Greenland. In recent years, the floating ice tongue has increased in velocity and a number of calving events have displayed the potential sensitivity of the glacier to changing conditions. Approximately 8% of the Greenland ice sheet drains into 79N, prompting belief that any instabilities may propagate upstream, and into the interior of the ice sheet. Melt ponds are a persistent feature on the surface of the glacier, and periodically drain to the base. Despite this, relatively little is known about the past or current meteorological conditions near the surface of 79°N. Without adequate knowledge of the climatology, the response of the glacier to future changes cannot be accurately assessed.

Here, I present analysis of the only meteorological observations taken on the floating tongue of the glacier. Sudden warming events, on the order of 10-40°C in 48 hours, are regularly observed. Using a 3-domain high-resolution setup of the Weather Research and Forecasting (WRF) model, I investigate the mechanisms responsible for an event with the largest magnitude of change.

Furthermore, details of the climatology of the region will be presented. From analysis of ERA -Interim reanalysis data, the annual air temperature over the last 35 years has increased by ~3°C. The inter-annual variability is largest in winter due to the increased variability of MSLP in the north Atlantic, and the high frequency of the sudden warming events. The combination of both leads to ‘coreless winters’ or the absence of a typical sinusoidal temperature signal. The impact of the both the short-term sudden warming events and the coreless winters on the surface mass balance of the glacier will be investigated in future work.