Climate and Dynamics
An analysis of satellite, radiosonde, and lidar observations of upper tropospheric water vapor from the Atmospheric Radiation Measurement Program
Article first published online: 25 FEB 2004
Copyright 2004 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 109, Issue D4, 27 February 2004
How to Cite
2004), An analysis of satellite, radiosonde, and lidar observations of upper tropospheric water vapor from the Atmospheric Radiation Measurement Program, J. Geophys. Res., 109, D04105, doi:10.1029/2003JD003828., , , and (
- Issue published online: 25 FEB 2004
- Article first published online: 25 FEB 2004
- Manuscript Accepted: 12 NOV 2003
- Manuscript Revised: 29 OCT 2003
- Manuscript Received: 2 JUN 2003
- upper tropospheric water vapor;
- remote sensing
 To improve our understanding of the distribution and radiative effects of water vapor, the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Program has conducted a series of coordinated water vapor Intensive Observation 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 colocated geostationary satellite radiances at 6.7 μm. 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.