Mesoscale Wind Variability near Point Conception, California during Spring 1983

Abstract

Wind variability in a mesoscale region near Point Conception, California is studied. The data base is derived from an array of near-surface meteorological recording stations yielding hourly winds during 51 days from 11 April to 31 May 1983, a transitionary period between seasons. Temporal variability of each record is examined using variance ellipses, rotary spectra, and complex demodulation. The results reveal large differences between the stations in the offshore or exposed areas compared to the sheltered or coastal areas within the Santa Barbara Channel. Considerable variability with 2?5-day periods occurred in the former region, while diurnal variability dominated the latter area. Also, diurnal fluctuations (sea breezes) were highly dependent upon the synoptic scale state. Spatial and temporal variability of all records were examined simultaneously by use of complex empirical orthogonal function (CEOF) analysis. Almost 85% of the total variance can be explained by the primary CEOF and this characteristic pattern may be identified with synoptic-scale forcing.