Water vapor paper accepted in J. Climate#

Our latest paper: The vertical structure of tropospheric water vapor: comparing radiative and ocean-driven climate changes, by Rose and Rencurrel, is now accepted for publication in Journal of Climate.

The paper looks at rates of change of precipitable water with surface temperature in a suite of simulations driven by different combinations of greenhouse gas forcing and prescribed ocean heat uptake. We find fractional rates ranging between 3.6 and 11 %/K globally. These results seem at first glance to suggest substantial departures from Clausius-Clapeyron scaling, but actually result from different spatial patterns of temperature change and nearly fixed relative humidity.

To reach this conclusion we developed a new diagnostic to decompose precipitable water changes into additive contributions from changes in surface temperature, lapse rates, and relative humidity. The central message is that different forcing mechanisms produce substantially different 3D patterns of temperature change, which constrain the vapor-storage capacity of the atmosphere in different ways.