The WSR-57 weather radar operated by the National
Weather Service at Sacramento, California, plus a network
of precipitation gages provided data for this comparison
of radar reflectivity with precipitation rates. Located
in a valley with mountains within range of the radar on
three sides, this radar has varying sensitivity for
precipitation rates as a result of the terrain effects.
Variation in the terrain surrounding the radar has led
to a very wide scatter in precipitation rates associated
with any particular radar reflectivity. The radar failed
to detect precipitation up to 77% of the time over the
Coast Range at ranges greater than 100 nm. Linear
regression analyses revealed very poor correlation between
the raingage indicated precipitation rate and the radar
reflectivity. These analyses resulted in values of (R²),
the coefficient of determination, ranging from zero as
a minimum to only 0.502 as a maximum. Such results are
generally much poorer than results obtained by others.
The poor correlations and both overestimation and
underestimation of rainfall resulted from factors such
as range, terrain blocking, windward or leeward exposure,
freezing level height, beam height and width, and the
distribution of water vapor in the vertical. / Graduation date: 1976
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29370 |
| Date | 30 June 1975 |
| Creators | Strem, Eric Thomas |
| Contributors | Decker, Fred W. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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