Results of Double-Theodolite Observations at Bishop, Cal., in Connection with the “Bishop-Wave” Phenomena *

Abstract

A double-theodolite pilot-balloon observation program was inaugurated at the Bishop, California, Weather Bureau station in order to obtain data on the actual air currents in that area. The results of the observations for the period from February through May 1951 are discussed. Comparisons between single- and double-theodolite computations are shown. The mean actual ascension rates are compared for each month, and the mean ascension rates for the entire period are compared with the standard assumed single-thodolite ascension rates. Relations between the mean actual ascension rates and the local topography, the elevation of the balloon, the direction and speed of the general upper-level wind are shown. Several examples are given showing the existence of the standing (“Bishop” or “Sierra”)-wave pattern in the double-theodolite data. In some cases, the location of the up and downdrafts as well as the horizontal wave length can be determined.