The March 1972 northwest Greenland windstorm: evidence of downslope winds associated with a trapped lee wave

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Author: Moore, G. W. K.
• Other Authors: Natural Sciences and Engineering Research Council of Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2016
• Subjects: Greenland; Ice cap
• Online Access: http://dx.doi.org/10.1002/qj.2744; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.2744; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.2744

Abstract In M arch 1972, a severe windstorm buffeted T hule A ir F orce B ase in northwest G reenland with sustained surface winds in excess of 30 m s −1 and gusts exceeding 90 m s −1 – one of the highest surface wind speeds ever directly observed. The high winds were associated with an extratropical cyclone that propagated into the region from the L abrador S ea. It has been argued that katabatic flow off the nearby ice cap contributed to the high winds during the event. Here we use surface and radiosonde data from the region along with an operational analysis as well as both conventional and ‘surface data’ reanalyses to examine the conditions in the region during the windstorm. We find that during the event there was southeasterly flow in the region suggesting that katabatic flow, which would have resulted in easterly or northeasterly flow, was not a significant contributor to the high winds observed at T hule. Rather, we find that the environmental conditions immediately prior to the event were conducive to the excitation of a trapped lee wave forced by the flow over the topographic ridge upwind of T hule. Radiosonde data during the event is consistent with this interpretation and suggests that downslope winds associated with this trapped lee wave were responsible for the observed high winds. Evidence is also presented that corner jets excited by the coastal topography also occur in the region and one such jet contributed to the high wind speeds during this event.