Impacts of sea spray geoengineering on ocean biogeochemistry. Issue 14 (22nd July 2016)

• Record Type: Journal Article
• Authors: Partanen, Antti‐Ilari; Keller, David P.; Korhonen, Hannele; Matthews, H. Damon
• Is Part Of: Geophysical research letters. Volume 43:Issue 14(2016)
• Page Start: 7600
• Page End: 7608
• Publication Date: 2016-07-22
• Subjects: geoengineering -- phytoplankton -- biogeochemical modeling -- carbon cycle -- net primary productivity -- Earth System Modeling; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2016GL070111
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: We used an Earth system model of intermediate complexity to study the effects of Solar Radiation Management (SRM) by sea spray geoengineering on ocean biogeochemistry. SRM slightly decreased global ocean net primary productivity (NPP) relative to the control run. The lower temperatures in the SRM run decreased NPP directly but also indirectly increased NPP in some regions due to changes in nutrient availability resulting from changes in ocean stratification and circulation. Reduced light availability had a minor effect on global total NPP but a major regional effect near the nutrient‐rich upwelling region off the coast of Peru, where light availability is the main limiting factor for phytoplankton growth in our model. Unused nutrients from regions with decreased NPP also fueled NPP elsewhere. In the context of RCP4.5 simulation used here, SRM decreased ocean carbon uptake due to changes in atmospheric CO2 concentrations, seawater chemistry, NPP, temperature, and ocean circulation. Key Points: Sea spray geoengineering changed regional ocean net primary productivity (NPP) significantly (± ~700 mg C m −2 d −1 ) in model simulations Changes in NPP were mainly caused by lower temperatures in the geoengineering run than in the control run instead of lower available light The geoengineering run had lower ocean carbon uptake than the control run (difference up to 0.08 Gt C yr −1 ) in a low‐CO2 emission scenario