Record Details
A statistical study of the correlation between the surface and surface geostrophic winds in the Wilamette Valley
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | A statistical study of the correlation between the surface and surface geostrophic winds in the Wilamette Valley |
| Names |
Andrews, Leta
(creator) Mahrt, Larry J. (advisor) |
| Date Issued | 1974-10-23 (iso8601) |
| Note | Graduation date: 1975 |
| Abstract | Relationships among the surface wind, horizontal synoptic-scale pressure gradient and topography are studied in the Willamette Valley in western Oregon. Terrain features alter the standard surface wind-pressure gradient relationship such that the angle between the surface wind and the surface geostrophic wind is most frequently 60°. In winter the surface flow is predominantly southerly and surface geostrophic flow varies from southerly to westerly. Little diurnal change occurs in the average surface wind, the average surface geostrophic wind and their relationship with each other because the air in the valley is generally stably stratified throughout the day. Partially in response to the northward extension of the subtropical anticyclone summertime surface winds and surface geostrophic winds are northerly, except during afternoon episodes of marine air invasion when surface winds are westerly. The pressure gradient is 88% less intense in summer but the ratio of the magnitudes of the surface wind and surface geostrophic wind, R, is 125% greater than in winter. However, a sharp summertime morning maximum in R of -0.67 is diminished by early afternoon as differential surface heating establishes a strong afternoon pressure gradient. When the surface geostrophic wind vector is cross-valley, the surface wind is still most frequently parallel to the valley and the surface geostrophic wind speed is largest and most variable. Because of the importance of terrain and meso-scale events, little correlation between the surface winds and synoptic-scale pressure gradient is found. |
| Genre | Thesis/Dissertation |
| Topic | Winds -- Oregon -- Willamette River Valley |
| Identifier | http://hdl.handle.net/1957/29501 |
