All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 302 140 64
PDF Downloads 66 32 3

A Comparison of Modeled and Observed Relationships between Interannual Variations of Water Vapor and Temperature

De-Zheng SunProgram in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey

Search for other papers by De-Zheng Sun in
Current site
Google Scholar
PubMed
Close
and
Isaac M. HeldGeophysical Fluid Dynamics Laboratory/N0AA, Princeton, New Jersey

Search for other papers by Isaac M. Held in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

The correlations between interannual variations of tropical mean water vapor and temperature in the simulations by a low resolution (R15) GCM are stronger than those in the rawinsonde observations. The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is also larger than that from the observations. The largest discrepancies are found in the region immediately above the tropical convective boundary layer (850–600 mb). The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is close to that for a constant relative humidity. The correlations between variations of water vapor in the upper troposphere and those in the lower troposphere are also stronger in the model simulations than in the observations. In the horizontal, the characteristic spatial patterns of the normalized water vapor variations in the model simulations and observations are similar. The water vapor–temperature relationship in simulations by a GCM with a somewhat higher spatial resolution (R30) is almost identical to that in the simulations by the low resolution (R15) GCM. The implications of these findings for the radiative feedback of water vapor are discussed.

Abstract

The correlations between interannual variations of tropical mean water vapor and temperature in the simulations by a low resolution (R15) GCM are stronger than those in the rawinsonde observations. The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is also larger than that from the observations. The largest discrepancies are found in the region immediately above the tropical convective boundary layer (850–600 mb). The rate of fractional increase of tropical mean water vapor with temperature in the model simulations is close to that for a constant relative humidity. The correlations between variations of water vapor in the upper troposphere and those in the lower troposphere are also stronger in the model simulations than in the observations. In the horizontal, the characteristic spatial patterns of the normalized water vapor variations in the model simulations and observations are similar. The water vapor–temperature relationship in simulations by a GCM with a somewhat higher spatial resolution (R30) is almost identical to that in the simulations by the low resolution (R15) GCM. The implications of these findings for the radiative feedback of water vapor are discussed.

Save