Water-vapor climate feedback inferred from climate fluctuations, 2003–2008
Article first published online: 23 OCT 2008
Copyright 2008 by the American Geophysical Union.
Geophysical Research Letters
Volume 35, Issue 20, October 2008
How to Cite
2008), Water-vapor climate feedback inferred from climate fluctuations, 2003–2008, Geophys. Res. Lett., 35, L20704, doi:10.1029/2008GL035333., , and (
- Issue published online: 23 OCT 2008
- Article first published online: 23 OCT 2008
- Manuscript Accepted: 19 SEP 2008
- Manuscript Revised: 16 SEP 2008
- Manuscript Received: 13 JUL 2008
- water vapor;
 Between 2003 and 2008, the global-average surface temperature of the Earth varied by 0.6°C. We analyze here the response of tropospheric water vapor to these variations. Height-resolved measurements of specific humidity (q) and relative humidity (RH) are obtained from NASA's satellite-borne Atmospheric Infrared Sounder (AIRS). Over most of the troposphere, q increased with increasing global-average surface temperature, although some regions showed the opposite response. RH increased in some regions and decreased in others, with the global average remaining nearly constant at most altitudes. The water-vapor feedback implied by these observations is strongly positive, with an average magnitude of λq = 2.04 W/m2/K, similar to that simulated by climate models. The magnitude is similar to that obtained if the atmosphere maintained constant RH everywhere.