Greenland has a major influence on the atmospheric circulation of the North Atlantic-western European region, dictating the location and strength of mesoscale weather systems around the coastal seas of Greenland and directly influencing synoptic-scale weather systems both locally and downstream over Europe. High winds associated with the local weather systems can induce large air-sea fluxes of heat, moisture, and momentum in a region that is critical to the overturning of the thermohaline circulation, and thus play a key role in controlling the coupled atmosphere-ocean climate system.

The Greenland Flow Distortion Experiment (GFDex) is investigating the role of Greenland in defining the structure and predictability of both local and downstream weather systems through a program of aircraft-based observation and numerical modeling. The GFDex observational program is centered upon an aircraft-based field campaign in February and March 2007, at the dawn of the International Polar Year. Twelve missions were flown with the Facility for Airborne Atmospheric Measurements' BAe-146, based out of the Keflavik, Iceland. These included the first aircraft-based observations of a reverse tip jet event, the first aircraft-based observations of barrier winds off of southeast Greenland, two polar mesoscale cyclones, a dramatic case of lee cyclogenesis, and several targeted observation missions into areas where additional observations were predicted to improve forecasts.

In this overview of GFDex the background, aims and objectives, and facilities and logistics are described. A summary of the campaign is provided, along with some of the highlights of the experiment.

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School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom

Department of Physics, University of Toronto, Toronto, Ontario, Canada

Department of Geophysics, University of Oslo, Oslo, Norway

Department of Physics, University of Iceland, Reykjavik, Iceland, and University of Bergen, Bergen, Norway

Department of Meteorology, University of Reading, Reading, United Kingdom

Met Office, Exeter, United Kingdom

Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, Maryland

European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom

Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

NOAA/Environmental Technology Laboratory, Boulder, Colorado

Facility for Airborne Atmospheric Measurement, Cranfield, United Kingdom