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Sea spray geoengineering experiments in the geoengineering model intercomparison project (GeoMIP): Experimental design and preliminary results
Author(s) -
Kravitz Ben,
Forster Piers M.,
Jones Andy,
Robock Alan,
Alterskjær Kari,
Boucher Olivier,
Jenkins Annabel K. L.,
Korhonen Hannele,
Kristjánsson Jón Egill,
Muri Helene,
Niemeier Ulrike,
Partanen AnttiIlari,
Rasch Philip J.,
Wang Hailong,
Watanabe Shingo
Publication year - 2013
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/jgrd.50856
Subject(s) - environmental science , cloud forcing , radiative forcing , climatology , climate model , aerosol , atmospheric sciences , forcing (mathematics) , climate change , albedo (alchemy) , cloud albedo , radiative transfer , arctic , coupled model intercomparison project , geoengineering , meteorology , cloud computing , cloud cover , oceanography , geology , geography , art , physics , quantum mechanics , performance art , computer science , art history , operating system
Marine cloud brightening through sea spray injection has been proposed as a method of temporarily alleviating some of the impacts of anthropogenic climate change, as part of a set of technologies called geoengineering. We outline here a proposal for three coordinated climate modeling experiments to test aspects of sea spray geoengineering, to be conducted under the auspices of the Geoengineering Model Intercomparison Project (GeoMIP). The first, highly idealized, experiment ( G1ocean‐albedo ) involves a uniform increase in ocean albedo to offset an instantaneous quadrupling of CO 2 concentrations from preindustrial levels. Results from a single climate model show an increased land‐sea temperature contrast, Arctic warming, and large shifts in annual mean precipitation patterns. The second experiment ( G4cdnc ) involves increasing cloud droplet number concentration in all low‐level marine clouds to offset some of the radiative forcing of an RCP4.5 scenario. This experiment will test the robustness of models in simulating geographically heterogeneous radiative flux changes and their effects on climate. The third experiment ( G4sea‐salt ) involves injection of sea spray aerosols into the marine boundary layer between 30°S and 30°N to offset 2 W m −2 of the effective radiative forcing of an RCP4.5 scenario. A single model study shows that the induced effective radiative forcing is largely confined to the latitudes in which injection occurs. In this single model simulation, the forcing due to aerosol‐radiation interactions is stronger than the forcing due to aerosol‐cloud interactions.