Effects of Sea Salt Aerosol Emissions for Marine Cloud Brightening on Atmospheric Chemistry: Implications for Radiative Forcing
| Autor: | Hannah M. Horowitz, Becky Alexander, Jiayue Huang, Christopher D. Holmes, Shuting Zhai, Mat J. Evans, Qianjie Chen, Lyatt Jaeglé, Alicia Wright, Xuan Wang, Tomás Sherwen |
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| Rok vydání: | 2019 |
| Předmět: |
Atmospheric Science
atmospheric chemistry food.ingredient Ozone 010504 meteorology & atmospheric sciences Chemical transport model General or Miscellaneous Atmospheric Composition and Structure 010502 geochemistry & geophysics Atmospheric sciences 01 natural sciences chemistry.chemical_compound Oceanography: Biological and Chemical food Paleoceanography geoengineering Research Letter marine cloud brightening Global Change Sea salt aerosol 0105 earth and related environmental sciences Aerosols Sea salt Radiative forcing Aerosols and Particles Research Letters Aerosol sea salt aerosols Geophysics Pollution: Urban and Regional chemistry Atmospheric chemistry Cloud albedo General Earth and Planetary Sciences Environmental science reactive halogens Troposphere: Composition and Chemistry |
| Zdroj: | Geophysical Research Letters |
| ISSN: | 0094-8276 |
| Popis: | Marine cloud brightening (MCB) is proposed to offset global warming by emitting sea salt aerosols to the tropical marine boundary layer, which increases aerosol and cloud albedo. Sea salt aerosol is the main source of tropospheric reactive chlorine (Cly) and bromine (Bry). The effects of additional sea salt on atmospheric chemistry have not been explored. We simulate sea salt aerosol injections for MCB under two scenarios (212–569 Tg/a) in the GEOS‐Chem global chemical transport model, only considering their impacts as a halogen source. Globally, tropospheric Cly and Bry increase (20–40%), leading to decreased ozone (−3 to −6%). Consequently, OH decreases (−3 to −5%), which increases the methane lifetime (3–6%). Our results suggest that the chemistry of the additional sea salt leads to minor total radiative forcing compared to that of the sea salt aerosol itself (~2%) but may have potential implications for surface ozone pollution in tropical coastal regions. Key Points Sea salt aerosol emissions for Marine Cloud Brightening geoengineering are implemented in a global chemical transport modelThis leads to changes in global tropospheric Bry and Cly (+20 to 40%), ozone (−3 to −6%), OH (−2 to −4%), and methane lifetime (+3 to 6%)Chemistry of the added sea salt leads to minor total radiative forcing (−20 to −50 mW/m2) but may have implications for ozone pollution |
| Databáze: | OpenAIRE |
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