A Reverse Tip Jet during the Greenland Flow Distortion experiment

Greenland is the third largest mountain range in the world. Its location and topography means it has a strong influence on the air flow in the region, and has a downstream effect on the weather patterns over Northern Europe. It also plays a major part in the production of many of the weather phenomenon observed in the area, including tip jets, barrier winds, lee cyclones and reverse tip jets. The Greenland Flow Distortion experiment (GFDex) has provided detailed measurements of a number of these weather phenomena, including the first in situ observations of a reverse (easterly) tip jet.

This reverse tip jet event was observed to have wind speed reaching nearly 50ms-1, and has been simulated using the UK Met Office Unified Model. While the model reproduces the overall event reasonably well, the simulations are sensitive to the boundary conditions e.g. SST, sea ice etc. The improvements made to the boundary conditions to allow the model to better simulate the event will be examined, along with a comparison of the models results to the in situ measurements, taken during the GFDex field campaign. The underlying dynamics of the event will also be discussed and a complete momentum budget will be presented.