Butene Emissions From Coastal Ecosystems May Contribute to New Particle Formation

Abstract

Marine ecosystems are important drivers of the global climate system. They emit volatile species into the atmosphere, involved in complex reaction cycles that influence the lifetime of greenhouse gases. Sea spray and marine biogenic aerosols affect Earth's climate by scattering solar radiation and controlling cloud microphysical properties. Here we show larger than expected marine biogenic emissions of butenes, three orders of magnitude higher than dimethyl sulfide, produced by the coastal part of the Benguela upwelling system, one of the most productive marine ecosystems in the world. We show that these emissions may contribute to new particle formation in the atmosphere within the marine boundary layer through production of Criegee intermediates that oxidize SO2 to H2SO4. Butene emissions from the marine biota may affect air quality and climate through ozone, secondary organic aerosol, and cloud condensation nuclei formation even in pristine regions of the world. Our results indicate a potentially important role of butene emissions in marine particle formation that requires investigation in other regions.

Marine biogenic emissions of benzene and toluene and their contribution to secondary organic aerosols over the polar oceans

“…Cruise mean ambient air benzene mole fractions were lower than typically observed at terrestrial or coastal sites (benzene, 14 ± 17 pmol mol −1 ) ( 25 , 29 ), while toluene mole fractions were essentially near zero and below the LOD for most of the cruise track. Such low ambient air mole fractions over the Southern Ocean are similar to observations by Guérette e t al.…”

“…The ratio between benzene and toluene has been used in the past to spot petroleum combustion plumes from local anthropogenic activity beyond the research/sampling vessel, as in the work of Giorio et al. ( 29 ) (see the Supporting Information thereof). A toluene/benzene ratio of 2 or above is generally considered indicative of fresh fossil fuel burning emissions.…”

“…Recently, Giorio et al (29) (see the Supporting Information thereof ) observed toluene in the headspace of seawater and ocean foam samples from the Benguela upwelling system. They evoked a biological source and a sea-to-air flux to explain the high toluene air mole fractions observed in marine air (29). Rocco et al (30) suggested a phytoplankton source of benzene and toluene in the surface ocean.…”

Sources and Distribution of Light NMHCs in the Marine Boundary Layer of the Northern Indian Ocean During Winter: Implications to Aerosol Formation

“…In a recent study, Giorio et al. (2022) reported significant contributions of marine biogenic butenes to the NPF in the productive coastal region of the Benguela upwelling system. The NPF in the MBL can impact the Earth's radiation budget through the formation of CCN and scattering and absorption of solar radiation (Donaldson & George, 2012; Zhu et al., 2019).…”

“…Due to their higher reactivity, alkenes can potentially influence the O 3 and OH concentrations in the marine atmosphere and also enhance particle formation in the pristine regions. In a recent study, Giorio et al (2022) reported significant contributions of marine biogenic butenes to the NPF in the productive coastal region of the Benguela upwelling system. The NPF in the MBL can impact the Earth's radiation budget through the formation of CCN and scattering and absorption of solar radiation (Donaldson & George, 2012;Zhu et al, 2019).…”