Extended Abstract (264K)P3.34
SNEX—The SNaefellsnes EXperiment
Haraldur Olafsson, University of Iceland and the Icelandic Meteorological Office, Reykjavik, Iceland; and H. Sigurjonsson and H. Agustsson
The SNaefellsnes EXperiment (SNEX) is an atmospheric field experiment in the Snaefellsnes peninsula in W-Iceland that took place from 1999-2002.
The purpose of SNEX is to gather data on local winds, with emphasis on downslope windstorms: their characteristics in time and space and how they are linked to the synoptic flow field. The goal is to establish a link between real weather and theories of simplified flow over mountains that have been developed during the last two decades.
Downslope windstorms are exceptionally frequent in Snaefellsnes, and unlike most mountain ridges, Snaefellsnes is almost surrounded by water and exceptionally well defined. This makes the area very well suitable for studies of the impact of mountains on the weather.
The field observations are mainly based on eight automatic weather stations in Snaefellsnes and radiosoundings from a site about a 100 km south of the mountain ridge. The automatic weather stations measure atmospheric pressure, temperature, humidity and winds. During events of strong windstorms data is collected with very high temporal resolution.
Two examples of typical downslope windstorms will be shown. In southerly windstorms gusts are often 40-50 m/s while the mean wind speed may only be 20-25 m/s. The airmass is stable, but a well defined inversion is not always present. Northerly windstorms are also gusty, but less frequent. They are usually associated with reverse wind shear at low levels. Amplified mountain waves are often observed during events of downslope windstorms.
Data from SNEX will undoubtedly serve for research of various aspects of mountain flow and it will be available in the near future.
Poster Session 3, Topographic Flows (with Coffee Break)
Thursday, 20 June 2002, 2:45 PM-4:30 PM
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