Water Vapor Feedback

A climate anomaly almost certainly leads to a perturbation to the atmosphere's humidity distribution.  Since water vapor is a strong absorber of infrared radiation, this would have a substantial impact on greenhouse trapping, and therefore would be a strong feedback to the original climate anomaly. The simplest hypothesis predicting how the humidity distribution is altered as climate changes is to assume that the atmosphere's relative humidity remains roughly constant as climate varies. Since the saturation mixing ratio of water vapor depends approximately exponentially on temperature, this implies a strongly positive water vapor feedback which roughly doubles the sensitivity of the climate system in the absence of other climate feedbacks. Much of the literature on water vapor feedback addresses the validity of this fixed relative humidity assumption.

Allan RP, Shine KP, Slingo A, Pamnet JA (1999) The dependence of clear-sky outgoing longwave radiation on surface temperature and relative humidity. Q.J.R. Meteor. Soc., 125, 2103-2126.

Bates JJ, Jackson DL (1997) A comparison of water vapor observations with AMIP I simulations. J. Geophys. Res., 102, 21,837-21,852. Download

Bates JJ, Jackson DL, Breon FM, Bergen ZD (2001) Variability of upper troposperic humidity 1979-1998. J. Geophys. Res., 106 (D23): 32,271-32,281. Download

Bony S, Duvel JP, Le Treut H (1995) Observed dependence of the water vapour and clear-sky greenhouse effect on sea surface temperature: comparison with climate warming experiments. Clim. Dyn., 11, 307-320.

Del Genio AD, Kovari W Jr, Yao MS (1994) Climatic implications of the seasonal variation of upper-troposphere water vapor. Geophys. Res. Lett., 21, 2701-2704. Download

Dessler AE, Sherwood SC (2000) Simulations of tropical upper-tropospheric humidity. J. Geophys. Res. 105(DI5), 20,155-20,163. Download

Elliott WP, Gaffen DJ (1991) On the utility of radiosonde humidity archives for climate studies. Bull. Am. Met. Soc., 72, 1507-1520. Download

Emanuel K, Pierrehumbert RT (1996) Microphysical and dynamical control of tropospheric water vapor. In Clouds, Chemistry, and Climate, NATO ASI Ser. 35, Springer-Verlag. 260.

Gaffen DJ, Rosen RD, Salstein DA, Boyle JS (1998) Evaluation of tropospheric water vapor simulations from the Atmospheric Model Intercomparison Project. J. Clim., 10, 1648-1661. Download

Hall A, Manabe S (1999) The role of water vapor feedback in unperturbed climate variability and global warming. J. Clim., 12, 2327-2346. Download

Hall A, Manabe S (2000) Effect of water vapor feedback on internal and anthropogenic variations of the global hydrologic cycle. J. Geophys. Res., 105(D5), 6935-6944. Download

Hall A, Manabe S (2000) ENSO Suppression in a Coupled Model Without Water Vapor Feedback. Clim. Dyn., 16, 393-403. Download

Held IM, Soden BJ (2000) Water vapor feedback and global warming. Annu Rev Energy Environ., 25, 441-475.

Inamdar AK, Ramanathan V (1998) Tropical and global scale interactions among water vapor, atmospheric greenhouse effect and surface temperature. J. Geophys. Res., 103, 32,177-32,194. Download

Kasting JF (1989) Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus. Icarus, 74, 472-494.

Lau KM, Ho CH, Chou MD (1996) Water vapor and cloud feedback over the tropical oceans: Can we use ENSO as a surrogate for climatic change? Geophys. Res. Lett., 23, 2971-2974. Download

Lindzen RS (1990) Some coolness concerning global warming. Bull. Am. Met. Soc., 71, 288-299. Download

Manabe S, Wetherald RT (1967) Thermal equilibrium of the atmosphere with a given distribution of relative humidity. J. Atmos. Sci., 24, 241-259. Download

Moller F (1963) On the influence of changes in CO2 concentration in air on the radiation balance of Earth's surface and on climate. J. Geophys. Res., 68, 3877-3886. Download

Raval A, Ramanathan V (1989) Observational determination of the greenhouse effect. Nature, 342, 758-762.

Rind D et al (1991) Positive water vapour feedback in climate models confirmed by satellite data. Nature, 349, 500-503.

Ross RJ, Elliott WP (1996) Tropospheric water vapor climatology and trends over North America: 1973-93. J. Clim., 9, 3561-3574. Download

Ross RJ, Gaffen DJ (1998) Comment on "Widespread tropical atmospheric drying from 1979-1995" by Schroeder and McGuirk. Geophys. Res. Lett., 25, 4357-4358. Download

Salath EP, Hartmann DL (1997) A trajectory analysis of tropical upper-tropospheric moisture and convection, J. Clim., 10, 2533-2547. Download

Salath EP, Hartmann DL (2000) Subsidence and upper-tropospheric drying along trajectories in a general circulation model. J. Clim., 13, 257-263. Download

Schneider EK, Kirtman BP, Lindzen RS (1999) Tropospheric water vapor and climate sensitivity. J. Atmos. Sci., 56, 1649-1658. Download

Schroder SR, McGuirk JP (1998) Widespread tropical atmospheric drying from 1979-1995. Geophys. Res. Lett., 25, 1301-1304. Download

Sherwood SC (1996) Maintenance of the free-tropospheric tropical water vapor distribution: II. Simulation by large-scale advection. J. Clim., 9, 2919-2934. Download

Shine KP, Sinha A (1991) Sensitivity of the earth's climate to height-dependent changes in the water vapour mixing ratio. Nature, 354, 38-84.

Soden BJ, Bretherton FP (1993) Upper tropospheric relative humidity from the GOES 6.7 micron channel: method and climatology for July 1987. J. Geophys. Res., 98, 16,669-16,688. Download

Soden BJ, Fu R (1995) A satellite analysis of deep convection, upper-tropospheric humidity and the greenhouse effect. J. Clim., 8, 2333-2351. Download

Soden BJ, Lanzante JR (1996) An assessment of satellite and radiosonde climatologies of upper-tropospheric water vapor. J. Clim., 9, 1235-1250. Download

Soden BJ (1997) Variations in the tropical greenhouse effect during El Nino. J. Clim., 10, 1050-1055. Download

Soden BJ, Schroeder SR (2000) Decadal variations in tropical water vapor: A comparison of observations and a model simulation. J. Clim., 13, 3337-3340. Download

Spencer RW, Braswell WD (1997) How dry is the tropical free troposphere? Implications for global warming theory. Bull. Am. Met. Soc., 78, 1097-1106. Download

Stephens GL, Greenwald TJ (1991) Observations of the earth's radiation budget in relation to atmospheric hydrology: I. Clear sky greenhouse effect and water vapor feedback. J. Geophys. Res., 96, 15,311-15,324. Download

Sun DZ, Lindzen RS (1993) Distribution of tropical tropospheric water vapor. J. Atmos. Sci., 50, 1643-1660. Download

Sun DZ, Held IM (1996) A comparison of modeled and observed relationships between interannual variations of water vapor and temperature. J. Clim., 9, 665-675. Download

Tompkins AM, Emanuel KA (2000) The vertical resolution sensitivity of simulated equilibrium temperature and water vapor profiles. Quart. J. Roy. Met. Soc., 126, 1219-1238.