Method and instrument for retrieving total columnar water vapor from solar transmittance

摘要

Abstract: The design of a three-channel solar radiometer for obtaining total columnar water vapor using solar transmittance and differential absorption is presented. Water vapor transmittance is determined using a modified Langley approach and converted to columnar water vapor using a band model developed at the University of Arizona. Several cases are presented in which columnar water vapor amounts determined using the current instrument and method are compared to sounding balloon results. Tests using simulated data indicate that columnar water vapor may be retrieved with an uncertainty less than 10%. !19