Organosulfates in aerosols downwind of an urban region in central Amazon

Journal Article · Thu Nov 01 04:00:00 EDT 2018 · Environmental Science: Processes & Impacts

DOI:https://doi.org/10.1039/c8em00413g· OSTI ID:1633049

Glasius, Marianne ^[1]; Bering, Mads S. ^[2]; Yee, Lindsay D. ^[3]; de Sa, S S. ^[4]; Isaacman-VanWertz, Gabriel ^[3]; Wernis, Rebecca ^[3]; Barbosa, Henrique ^[5]; Alexander, M L. ^[6]; Palm, Brett B. ^[7]; Hu, Weiwei ^[7]; Campuzano-Jost, Pedro ^[8]; Day, D A ^[7]; Jimenez, Jose L. ^[8]; Shrivastava, ManishKumar B. ^[9]; Martin, Scot T. ^[4]; Martin, Scot T. ^[4]; Goldstein, Allen H. ^[3]

---

1. VISITORS
2. Aarhus Universitet
3. University of California, Berkeley
4. Harvard University
5. Universidade Federal de So Paulo
6. PNNL
7. University of Colorado at Boulder
8. University of Colorado
9. BATTELLE (PACIFIC NW LAB)

Organosulfates are formed in the atmosphere from reactions between reactive organic compounds (such as oxidation products of isoprene) and acidic sulfate aerosol. Here we investigated speciated organosulfates in an area typically downwind of the city of Manaus situated in the Amazon forest in Brazil during “GoAmazon2014/5” in both the wet se,son (February–March) and dry season (August–October). We observe products consistent with the reaction of isoprene photooxidation products and sulfate aerosols, leading to formation of several types of isoprene-derived organosulfates, which contribute 3% up to 42% of total sulfate aerosol measured by aerosol mass spectrometry. During the wet season the average contribution of summed organic sulfate concentrations to total sulfate was 19 10% and similarly during the dry season the contribution was 19 8%. This is the highest fraction of speciated organic sulfate to total sulfate observed at any reported site. Organosulfates appeared to be dominantly formed from isoprene epoxydiols (IEPOX), averaging 104 73 ng m3 (range 15–328 ng m3) during the wet season, with much higher abundance 610 400 ng m3 (range 86–1962 ng m3) during the dry season. The concentration of isoprene-derived organic sulfate correlated with total inorganic sulfate (R2 ¼ 0.35 and 0.51 during the wet and dry seasons, respectively), implying the significant influence of inorganic sulfate aerosol for the heterogeneous reactive uptake of IEPOX. Organosulfates also contributed to organic matter in aerosols (3.5 1.9% during the wet season and 5.1 2.5% during the dry season). The present study shows that an important fraction of sulfate in aerosols in the Amazon downwind of Manaus consists of multifunctional organic chemicals formed in the atmosphere, and that increased SO2 emissions would substantially increase SOA formation from isoprene.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1633049
• Report Number(s): PNNL-SA-139877
• Journal Information: Environmental Science: Processes & Impacts, Journal Name: Environmental Science: Processes & Impacts Journal Issue: 11 Vol. 20
• Country of Publication: United States
• Language: English