In the fall of 1997 the Atmospheric Radiation Measurement program conducted a study of water-vaporabundance-measurement at its southern Great Plains site. The large number of instruments included four solar radiometers to measure the columnar water vapor (CWV) by measuring solar transmittance in the 0.94-micrometer water-vapor absorption band. At first, no attempt was made to standardize our procedures to the same radiative transfer model and its underlying water-vapor spectroscopy. In the second round of comparison we used the same line-by-line code (which includes recently corrected H2O spectroscopy) to retrieve CWV from all four solar radiometers, thus decreasing the mean CWV by 8–13%. The remaining spread of 8% is an indication of the other-than-model uncertainties involved in the retrieval.
Revised: June 9, 2004 |
Published: April 20, 2001
Citation
Schmid B., J.J. Michalsky, D.W. Slater, J.C. Barnard, R. Halthore, J.C. Liljegren, and B.N. Holben, et al. 2001.Comparison of Columnar Water-Vapor Measurements from Solar Transmittance Methods.Applied Optics 40, no. 12:1886-1896.PNNL-SA-34665.