20-MICRON TRANSPARENCY AND ATMOSPHERIC WATER VAPOR AT THE WYOMING INFRARED OBSERVATORY

Abstract

ABSTRACT The authors have examined the atmospheric transparency at 19.5 and 23 μm from the Wyoming Infrared Observatory over the past six years. They find that the transparency is largely controlled by the season. Four months: June, July, August, and September have very poor 20-μm transparency. During the rest of the year the transparency is usually quite good at 19.5 μm and moderately good at 23 μm. Using Rawinsonde data and theoretical calculations for the expected infrared transparency the authors have calibrated their measures of 20-micron transparency in terms of atmospheric water-vapor content. The water vapor over the Wyoming Infrared Observatory is found to compare favorably with that above other proposed or developed sites: Mauna Kea, Mount Graham, and Wheeler Peak.