Chemical Speciation of Sulfur in Marine Cloud Droplets and Particles: Analysis of Individual Particles from the Marine Boundary Layer Over the California Current

Journal Article · Wed Feb 27 00:00:00 EST 2008 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/2007JD008954· OSTI ID:985029

Hopkins, Rebecca J; Desyaterik, Yury; Tivanski, Alexei V; Zaveri, Rahul A; Berkowitz, Carl M; Tyliszczak, T; Gilles, Marry K; Laskin, Alexander

Detailed chemical speciation of the dry residue particles from individual cloud droplets and interstitial aerosol collected during the Marine Stratus Experiment (MASE) was performed using a complementary combination of microanalysis techniques. Techniques include computer controlled scanning electron microscopy with energy dispersed analysis of X-rays (CCSEM/EDX), time-of-flight secondary ionization mass spectrometry (TOFSIMS), and scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). Samples were collected at the ground site located in Point Reyes National Seashore, approximately 1 km from the coast. This manuscript focuses on the analysis of individual particles sampled from an air mass that originated over the open ocean and then passed through the area of the California current located along the northern California coast. Based on composition, morphology, and chemical bonding information, two externally mixed, distinct classes of sulfur containing particles were identified: chemically modified (aged) sea salt particles and secondary formed sulfate particles. The results indicate substantial heterogeneous replacement of chloride by methanesulfonate (CH₃SO₃^-) and non-sea salt sulfate (nss-SO₄^2-) in sea-salt particles with the characteristic ratios of CH₃SO₃^-/nss-SO₄^2-> 0.6. Although this value seems too high for a mid-latitude site, our model calculations suggest that high CH₃SO₃^-/nss-SO₄^2- ratios are expected during the early stages of dimethyl sulfide (DMS) oxidation when CH₃SO₃H forms more rapidly than H₂SO₄.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Environmental Molecular Sciences Lab. (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 985029
• Report Number(s): PNNL-SA-55376; 19792; KP1704020; TRN: US201016%%1722
• Journal Information: Journal of Geophysical Research, Vol. 113, Issue d4; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ABSORPTION
AEROSOLS
BONDING
BOUNDARY LAYERS
CHLORIDES
CLOUDS
DIMETHYL SULFIDE
FINE STRUCTURE
INTERSTITIALS
IONIZATION
MASS SPECTROSCOPY
MICROANALYSIS
MICROSCOPY
MORPHOLOGY
OXIDATION
RESIDUES
SCANNING ELECTRON MICROSCOPY
SPECTROSCOPY
SULFATES
SULFUR
sea salt particles
methanesulfonate
nss-sulfate
Environmental Molecular Sciences Laboratory