Heterogeneous Reactivity of HCI on CaCO3 Aerosols at Stratospheric Temperature

R e ce n t l y proposed as a possible alternative to sulfatep.fffciesfor stratospheric solartadiationmanagemen management (SSRM), calcite (CaCO3) aerosoishavebeenmndeled to have minimal negativeimpactonburhstratosPhericozonelevel, through heterogeneous chemlsrr'anCstratospherictemperatore. However, the heterogeneous chemistry of CaCO3 aerosols with relevant tracegasessuchasHcf, atstratosphericconditionsisstill underexamined. We studied the kinericsefmciuptakeonairborne r soot xCaC 3aerosolsatstratosph:rictemperature,207 3Kiby performing experuentsunderdtyconditionsusinganaeroshifow tube coupled with acuston-h-iltuuadrhpolechemica110nizationnassspecttometer(C iM S) for HCl detecr- o n The' reactive uptake coefficient for HCI was measured to be 0.076 o.009.Thisexceedsthereactiveupfakecoefficientof0.013+o-00lthat we previouslyreported for thissystemai,u6 K, consistenfvffnfhee21ected negativetemperaturedependence0fgasuptakeuusurid surfaces.Thisfindingsuggests an initial strong reactive uptakeot4cigasuucacoaaerosol surfaces in the stratosphere. ICEI ozone,solarradiationnanagement, stratospheric aerosol

Automated summary

Calcite aerosols have been suggested as a potential alternative for stratospheric solar radiation management, with minimal negative impact on stratospheric ozone levels and temperature. However, the heterogeneous chemistry of calcite aerosols with trace gases, such as HCl, at stratospheric conditions, particularly their strong reactive uptake capability, needs further examination.