An Analysis of Satellite, Radiosonde, and Lidar Observations of Upper Tropospheric Water Vapor from the Atmospheric Radiation Measurement Program

Journal Article · Wed Feb 25 04:00:00 EST 2004 · Journal of Geophysical Research. D. (Atmospheres), 109(D4):D04105

DOI:https://doi.org/10.1029/2003JD003828· OSTI ID:15010589

Soden, Brian J; Turner, David D; Lesht, B M; Miloshevich, Larry M

To improve our understanding of the distribution and radiative effects of water vapor, the U.S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has conducted a series of coordinated water vapor Intensive Observational Periods (IOPs). This study uses observations collected from four ARM IOPs to accomplish two goals: first, we compare radiosonde and Raman lidar observations of upper tropospheric water vapor with co-located geostationary satellite radiances at 6.7 micrometers. During all four IOPs, we find excellent agreement between the satellite and Raman lidar observations of upper tropospheric humidity with systematic differences of ~10%. In contrast, radiosondes equipped with Vaisala sensors are shown to be systematically drier in the upper troposphere by ~40% relative to both the lidar and satellite measurements. Second, we assess the performance of various "correction" strategies designed to rectify known deficiencies in the radiosonde measurements. It is shown that existing methods for correcting the radiosonde dry bias, while effective in the lower troposphere, offer little improvement in the upper troposphere. An alternative method based on variational assimilation of satellite radiances is presented and, when applied to the radiosonde measurements, is shown to significantly improve their agreement with coincident Raman lidar observations. It is suggested that a similar strategy could be used to improve the quality of the global historical record of radiosonde water vapor observations during the satellite era.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15010589
• Report Number(s): PNNL-SA-39836; KP1201030
• Journal Information: Journal of Geophysical Research. D. (Atmospheres), 109(D4):D04105, Journal Name: Journal of Geophysical Research. D. (Atmospheres), 109(D4):D04105
• Country of Publication: United States
• Language: English