Composition and Chemistry
Validation of ground-based microwave radiometers at 22 GHz for stratospheric and mesospheric water vapor
Article first published online: 8 DEC 2009
Copyright 2009 by the American Geophysical Union.
Journal of Geophysical Research: Atmospheres (1984–2012)
Volume 114, Issue D23, 16 December 2009
How to Cite
2009), Validation of ground-based microwave radiometers at 22 GHz for stratospheric and mesospheric water vapor, J. Geophys. Res., 114, D23305, doi:10.1029/2009JD011997., , , , , , , , , and (
- Issue published online: 8 DEC 2009
- Article first published online: 8 DEC 2009
- Manuscript Accepted: 29 JUL 2009
- Manuscript Revised: 22 JUL 2009
- Manuscript Received: 3 MAR 2009
- water vapor;
- middle atmosphere
 We present a detailed intercomparison of five ground-based 22 GHz microwave radiometers for stratospheric and mesospheric water vapor. Four of these instruments are members of the Network for the Detection of Atmospheric Composition Change (NDACC). The global measurements of middle atmospheric water vapor of the Microwave Limb Sounder (MLS) onboard the Aura satellite serve as reference and allow intercomparison of the ground-based systems that are located between 45°S and 57°N. The retrievals of water vapor profiles from the ground-based radiation measurements have been made consistent to a large extent: for the required temperature profiles, we used the global temperature measurements of MLS and we agreed on one common set of spectroscopic parameters. The agreement with the reference measurements is better than ±8% in the altitude range from 0.01 to 3 hPa. Strong correlation is found between the ground-based and the reference data in the mesosphere with respect to seasonal cycle and planetary waves. In the stratosphere the measurements are generally more noisy and become sensitive to instrumental instabilities toward lower levels (pressures greater than 3 hPa). We further present a compilation of a NDACC data set based on the retrieval parameters described herein but using a temperature climatology derived from the MLS record. This makes the ground-based measurements independent of additional information and allows extension of the data set for years in a homogeneous manner.