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Volume 8, Issue 10 (Suppl)
J Earth Sci Clim Change, an open access
ISSN: 2157-7617
Climate Change 2017
October 19-21, 2017
Page 22
conference
series
.com
CLIMATE CHANGE
October 19-21, 2017 | Rome, Italy
4
th
World Conference on
Agustin J Colussi, J Earth Sci Clim Change 2017, 8:10(Suppl)
DOI: 10.4172/2157-7617-C1-035
Autocatalytic conversion of oceanic dimethyl sulfide emissions into cloud condensations nuclei
affecting the Earth’s albedo
T
he oxidation of biogenic dimethyl sulfide (DMS) emissions is a global source of cloud condensation nuclei. The amounts
of the nucleating H
2
SO
4
(g) species produced in such process, however, remain uncertain. Hydrophobic DMS is mostly
oxidized in the gas-phase into H
2
SO
4
(g)+DMSO (g) (dimethyl sulfoxide), whereas water-soluble DMSO is oxidized into
H
2
SO
4
(g) in the gas-phase but into SO4
2
-+MeSO3
-
(methane sulfonate) on water surfaces. Thus, R=MeSO3
-
/non-sea-salt-
SO4
2
- ratios would therefore gauge both the strength of DMS sources and the extent of DMSO heterogeneous oxidation
if Rhet=MeSO3
-
/SO4
2
- for DMSO(aq)+•OH(g) were known. Here, we report that Rhet=2.7, a value obtained from online
electrospray mass spectra of DMSO (aq)+•OH (g) reaction products, which quantifies the MeSO3
-
produced in DMSO
heterogeneous oxidation on aqueous aerosols for the first time. On this basis, the inverse R-dependence on particle radius
in size-segregated aerosol collected over Syowa station and Southern oceans is shown to be consistent with the competition
between DMSO gas-phase oxidation and its mass accommodation followed by oxidation on aqueous droplets. Geographical
R variations are thus associated with variable contributions of the heterogeneous pathway to DMSO atmospheric oxidation,
which increase with the specific surface area of local aerosols.
Biography
Agustin J Colussi is a Research Professor at California Institute of Technology, USA since 1998 and has published more than 200 papers in environmental physical
chemistry.
ajcoluss@caltech.eduAgustin J Colussi
Linde Center for Global Environmental Science, USA