Isotopic constraints on the origin of reactive chlorine in the troposphere.

ABSTRACT: Oceanic and anthropogenic processes, such as sea-salt emissions and combustion activities, release substantial amount of reactive chlorine into the troposphere, affecting air quality, ozone depletion, and climate change. However, distinguishing between these sources for reactive chlorine remains challenging. Here, we establish isotopic constraints on the origin of tropospheric reactive chlorine using chemical ionization mass spectrometry to analyze nitryl chloride (ClNO₂). Field observations from four regions in China reveal a much broader isotopic value (δ³⁷Cl) range for ClNO₂ (-21 to +39‰) than previously documented for Earth's chlorine reservoirs. Notably, significant δ³⁷Cl differences for ClNO₂ from sea-salt emissions (-9 ± 4‰) and

SUBMITTER: Zong Z 

PROVIDER: S-EPMC12810628 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature