Statistical Characterization of Precipitable Water Vapor at San Pedro Martir Sierra in Baja California

Abstract

We present time series of precipitable water vapor (PWV) for San Pedro Martir Sierra in 2006, obtained from measurements of atmospheric emission as a function of elevation angle from a 210 GHz tipping radiometer. These radiometric measurements are employed together with collocated surface temperature and pressure data to determine a mathematical relationship for the conversion of 210 GHz zenith optical depth to PWV in the atmospheric column for San Pedro Martir. The PWV time series are statistically analyzed to gain insights on its probability density function and cumulative distributions, as well as to learn the number of continuous hours over a year that the PWV remains below given thresholds, namely 1 mm, 2 mm, and 3 mm. This information is of interest to evaluate the expected performance of telescopes operating from optical to millimeter wavelengths at this site.