Organic carbon in marine atmospheric particulate matter: Concentration and particle size distribution

Abstract

Organic carbon (OC) was determined in atmospheric particulate matter collected at several remote marine locations in the northern and southern hemispheres (Bermuda, Hawaii, Samoa). The OC concentrations were rather similar at all three locations, generally ranging from 0.2 to 0.4 µg/m³ STP. The major mass of the OC at all three locations was found on the smallest particles (radii less than 0.5 µm). However, the major mass of OC on laboratory generated atmospheric sea salt particles was found on particles with radii from 1‐3 µm, the same size as the major mass of the sea salt in both the laboratory experiments and in ambient marine air. This suggests that most of the organic material in marine atmospheric particulate matter is not associated with sea salt. Gas‐particle interactions involving organic compounds could explain the observed size distribution of the OC‐containing particles and the rather constant concentrations of organic carbon found in marine atmospheric particulate matter at the locations studied.

Transport and diagenesis of dissolved and particulate terrigenous organic matter in the North Pacific Ocean

“…Indications are that the 0.1-0.7 mm size fraction could account for as much as 40-50% of suspended POC Altabet, 1990). Studies have shown that carbon associated with aerosol particles are largely in this size fraction (Hoffman and Duce, 1977;Chesselet et al, 1981) and that the d 13 C of aerosols (À26.5 to À26.7%) over the Pacific and Atlantic Oceans indicate a terrigenous origin (Chesselet et al, 1981). A simple mixing model, in which all particles greater than 0.7-0.8 mm are considered marine with a d 13 C of À22%, and all smaller particles are considered terrestrial with a d 13 C of À27%, results in total particulate d 13 C values more depleted than À24%.…”

On aerosol production and enrichment by breaking wind waves

“…Wallace and Duce (1978) report enrichments of particulate organic matter of about 50 in a froth. Hoffman and Duce (1976) found aerosol enrichments of 250 for near-shore samples and of 75 for Sargasso Sea samples. Gershey (1983) found enrichments of the order of 300 to 500 for North Atlantic waters.…”

“…Of increasing interest has been the enrichment of various trace constituents of the ocean in the aerosol, including bacteria (Blanchard and Syzdek, 1982), viruses (Bayloret al, 1977), heavy metals (Duce, 1982), radioactivity (Fraizier et al, 1977), as well as inert organic material (Hoffman and Duce, 1977;Gagosianetal., 1982;Wallace and Duce, 1978). Jacobs (1937) was the first to link the bubbling process with the production of aerosol from the ocean.…”

Potential origin of organic cloud condensation nuclei observed at marine site

“…Laboratory studies have suggested that submicrometer sea-salt particles will contain enriched amounts of organics from the ocean surface layer [Hoffman and Duce, 1976]. Thus it is reasonable that our simulation consider an organic particle flux.…”