Record Details
On the relationship between winter storms, strong winds, and the associated pressure field along a rugged western coast
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | On the relationship between winter storms, strong winds, and the associated pressure field along a rugged western coast |
| Names |
McDonough, Thomas Andrew
(creator) Decker, Fred W. (advisor) |
| Date Issued | 1976-09-21 (iso8601) |
| Note | Graduation date: 1977 |
| Abstract | Two successive years of wind speed and direction data, from January 1973 through December 1974, have been measured and recorded at Yaquina Head, 6 km north of Newport, Oregon. Analysis of the data permitted 65 cases of strong wind to be isolated and separated into four distinct wind speed categories. With the aid of surface charts, upper air sounding, and sea level pressures from several stations, numerous meteorological events, occurring concurrently with peak winds at Yaquina Head, have been evaluated for a significant contribution to the local wind. Cyclone centers associated with strong coastal wind have been plotted and analyzed with regard to location, speed and direction of motion, sea surface pressure, and pressure change during periods of strong winds. The result of this analysis indicates that many cases of strong coastal wind measured at Yaquina Head are associated with cyclones located southwest of Vancouver Island, British Columbia. The pressure change experienced by these cyclones is related to the strength of the observed wind at Yaquina Head. Likewise, the locations of these pressure centers are related to the duration of strong wind measured at Yaquina Head. The direction of motion of the cyclones and the value of the sea surface pressure at the center of the cyclones seem unrelated to local wind speed. Frontal zones associated with cases of strong wind have been evaluated with regard to type, speed, and direction of motion prior to strong surface winds. No relationship was found between these factors and the strength of the wind. The direction of the wind versus the speed of the wind was reviewed and the results were separated into several classes. The result of this classification indicated that in 73 percent of the cases the measured peak wind occurred prior to an abrupt veering of the wind. Only 21 percent of the cases lacked this wind shift. The local pressure field was examined for pressure differences which might result in a strong coastal wind flow. Station pressures from three locations were used as well as barograms from Newport, Oregon, in describing the pressure field. No correlation between these pressures differences and the strength of the local wind could be found. Finally, the north-south component of the geostrophic wind was calculated and compared with speed of the measured wind. No consistent agreement could be established between the measured surface wind speed and the calculated north- south component of the geostrophic wind. The lack of data west of Yaquina Head and Oregon Coast continue to present a problem for those who consider coastal winds. |
| Genre | Thesis/Dissertation |
| Topic | Atmospheric pressure |
| Identifier | http://hdl.handle.net/1957/28951 |
