An energetic perspective on hydrological cycle changes in the Geoengineering Model Intercomparison Project. Issue 23 (11th December 2013)

• Record Type: Journal Article
• Authors: Kravitz, Ben; Rasch, Philip J.; Forster, Piers M.; Andrews, Timothy; Cole, Jason N. S.; Irvine, Peter J.; Ji, Duoying; Kristjánsson, Jón Egill; Moore, John C.; Muri, Helene; Niemeier, Ulrike; Robock, Alan; Singh, Balwinder; Tilmes, Simone; Watanabe, Shingo; Yoon, Jin‐Ho
• Is Part Of: Journal of geophysical research. Volume 118:Issue 23(2013)
• Page Start: 13, 087
• Page End: 13, 102
• Publication Date: 2013-12-11
• Subjects: Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1002/2013JD020502
• Languages: English
• ISSNs: 2169-897X

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>[1] Analysis of surface and atmospheric energy budget responses to CO<sub>2</sub> and solar forcings can be used to reveal mechanisms of change in the hydrological cycle. We apply this energetic perspective to output from 11 fully coupled atmosphere‐ocean general circulation models simulating experiment <italic>G1</italic> of the Geoengineering Model Intercomparison Project (GeoMIP), which achieves top‐of‐atmosphere energy balance between an abrupt quadrupling of CO<sub>2</sub> from preindustrial levels (<italic>abrupt4xCO2</italic>) and uniform solar irradiance reduction. We divide the climate system response into a <italic>rapid adjustment</italic>, in which climate response is due to adjustment of the atmosphere and land surface on short time scales, and a <italic>feedback response</italic>, in which the climate response is predominantly due to feedback related to global mean temperature changes. Global mean temperature change is small in <italic>G1</italic>, so the feedback response is also small. <italic>G1</italic> shows a smaller magnitude of land sensible heat flux rapid adjustment than in <italic>abrupt4xCO2</italic> and a larger magnitude of latent heat flux adjustment, indicating a greater reduction of evaporation and less land temperature increase than <italic>abrupt4xCO2</italic>. The sum of surface flux changes in <italic>G1</italic> is small, indicating little ocean heat uptake. Using an energetic perspective to assess precipitation changes, <italic>abrupt4xCO2</italic> shows decreased mean evaporative moisture flux and increased moisture convergence, particularly over land. However, most changes in precipitation in <italic>G1</italic> are in mean evaporative flux, suggesting that changes in mean circulation are small.</p> </abstract>