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Observations of water vapor by ground-based microwave radiometers and Raman lidarIn November to December 1991, a substantial number of remote sensors and in situ instruments were operated together in Coffeyville, Kansas, during the climate experiment First ISCCP Regional Experiment Phase 2 (FIRE 2). Includede in the suite of instruments were (1) the NOAA Environmental Technology Laboratory (ETL) three-channel microwave radiometer, (2) the NASA GSFC Raman lidar, (3) ETL radio acoustic sounding system (RASS), and (4) frequent, research-quality radiosondes. The Raman lidar operated only at night and the focus of this portion of the experiment concentrated on clear conditions. The lidar data, together with frequent radiosondes and measurements of temperature profiles (every 15 min) by RASS allowed profiles of temperature and absolute humidity to be estimated every minute. We compared 20 min measurements of brightness temperature (T(sub b) with calculations of T(sub b) that were based on the Liebe and Layton (1987) and Liebe et al. (1993) microwave propagation models, as well as the Waters (1976) model. The comparisons showed the best agreement at 20.6 GHz with the Waters model, with the Liebe et al. (1993) model being best at 31.65 GHz. The results at 90 GHz gave about equal success with the Liebe and Layton (1987) and Liebe et al. (1993) models. Comparisons of precipitable water vapor derived independently from the two instruments also showed excellent agreement, even for averages as short as 2 min. The rms difference between Raman and radiometric determinations of precipitable water vapor was 0.03 cm which is roughly 2%. The experiments clearly demonstrate the potential of simultaneous operation of radiometers and Raman lidars for fundamental physical studies of water vapor.
Document ID
19950052928
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Han, Yong
(National Oceanic and Atmospheric Administration, Boulder, CO United States)
Snider, J. B.
(National Oceanic and Atmospheric Administration, Boulder, CO United States)
Westwater, E. R.
(National Oceanic and Atmospheric Administration, Boulder, CO United States)
Melfi, S. H.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Ferrare, R. A.
(Hughes-STX Corp. Lanham, MD, United States)
Date Acquired
August 16, 2013
Publication Date
September 20, 1994
Publication Information
Publication: Journal of Geophysical Research
Volume: 99
Issue: D9
ISSN: 0148-0227
Subject Category
Meteorology And Climatology
Accession Number
95A84527
Distribution Limits
Public
Copyright
Other

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