Premium
Effects of Sea Salt Aerosol Emissions for Marine Cloud Brightening on Atmospheric Chemistry: Implications for Radiative Forcing
Author(s) -
Horowitz Hannah M.,
Holmes Christopher,
Wright Alicia,
Sherwen Tomás,
Wang Xuan,
Evans Mat,
Huang Jiayue,
Jaeglé Lyatt,
Chen Qianjie,
Zhai Shuting,
Alexander Becky
Publication year - 2020
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2019gl085838
Subject(s) - sea salt , sea salt aerosol , aerosol , cloud albedo , atmospheric sciences , radiative forcing , environmental science , troposphere , dimethyl sulfide , tropospheric ozone , atmospheric chemistry , climatology , ozone , meteorology , chemistry , cloud cover , geology , cloud computing , geography , sulfur , organic chemistry , computer science , operating system
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 (Cl y ) and bromine (Br y ). 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 Cl y and Br y 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.