An overview of barrier winds off southeastern Greenland during the Greenland Flow Distortion experiment
During the Greenland Flow Distortion experiment, barrier flow was observed by an instrumented aircraft on 1, 2, 5 and 6 March 2007 off southeastern Greenland. During this time period the barrier flow increased from a narrow jet, ~15 m s-1, to a jet filling almost the whole of the Denmark Strait with...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | unknown |
Published: |
2009
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Subjects: | |
Online Access: | https://ueaeprints.uea.ac.uk/id/eprint/24340/ https://doi.org/10.1002/qj.455 |
Summary: | During the Greenland Flow Distortion experiment, barrier flow was observed by an instrumented aircraft on 1, 2, 5 and 6 March 2007 off southeastern Greenland. During this time period the barrier flow increased from a narrow jet, ~15 m s-1, to a jet filling almost the whole of the Denmark Strait with maximum wind speed exceeding 40 m s-1. Dropsonde observations show that the barrier flow was capped by a sharp temperature inversion below mountain height. Below the inversion was a cold and dry jet, with a larger northerly wind component than that of the flow above, which was also warmer and more moist. Thus, the observations indicate two air masses below mountain height: a cold and dry barrier jet of northern origin and, above this, a warmer and moister air mass that was of cyclonic origin. Numerical simulations emphasize the non-stationarity of the Greenland barrier flow and its dependence on the synoptic situation in the Greenland--Iceland region. They show that the barrier jet originated north of the Denmark Strait and was drawn southward by a synoptic-scale cyclone, with the strength and location of the maximum winds highly dependent on the location of the cyclone relative to the orography of Greenland. Experiments without Greenland's orography suggest a ~20 m s-1 enhancement of the low-level peak wind speeds due to the presence of the barrier. Thus, the Greenland barrier flows are not classic geostrophically balanced barrier flows but have a significant ageostrophic component and are precisely controlled by synoptic-scale systems. |
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