Chemical Signatures of Seasonally Unique Anthropogenic Influences on Organic Aerosol Composition in the Central Amazon
Journal Article
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· Environmental Science and Technology
- Univ. of California, Berkeley, CA (United States); Colorado State Univ., Fort Collins, CO (United States); University of California, Berkeley
- Univ. of California, Berkeley, CA (United States)
- Univ. of California, Berkeley, CA (United States); Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
- Aerosol Dynamics, Inc., Berkeley, CA (United States)
- Univ. of California, Berkeley and Riverside, CA (United States)
- Univ. of Colorado, Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences (CIRES); National Center for Atmospheric Research (NCAR), Boulder, CO (United States)
- Univ. of Colorado, Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences (CIRES); Chinese Academy of Sciences (CAS), Guangzhou (China). Guangzhou Institute of Geochemistry
- Univ. of Colorado, Boulder, CO (United States). Cooperative Inst. for Research in Environmental Sciences (CIRES)
- National Institute for Space Research (INPE), São Paulo (Brazil)
- Univ. of Sao Paulo (Brazil)
- Amazonas State University, Manaus (Brazil)
- Harvard Univ., Cambridge, MA (United States)
Urbanization and fires perturb the quantities and composition of fine organic aerosol in the central Amazon, with ramifications for radiative forcing and public health. These disturbances include not only direct emissions of particulates and secondary organic aerosol (SOA) precursors, but also changes in the pathways through which biogenic precursors form SOA. The composition of ambient organic aerosol is complex and incompletely characterized, encompassing millions of potential structures relatively few of which have been synthesized and characterized. Through analysis of submicron aerosol samples from the Green Ocean Amazon (GoAmazon2014/5) field campaign by two-dimensional gas chromatography coupled with machine learning, ~1300 unique compounds were traced and characterized over two seasons. Fires and urban emissions produced chemically and interseasonally distinct impacts on product signatures, with only ~50% of compounds observed in both seasons. Seasonally unique populations point to the importance of aqueous processing in Amazonian aerosol ageing, but further mechanistic insights are impeded by limited product identity knowledge. Further, less than 10% of compounds were identifiable at an isomer-specific level. Overall, the findings (i) provide compositional characterization of anthropogenic influence on submicron organic aerosol in the Amazon, (ii) identify key season-to-season differences in chemical signatures, and (iii) highlight high-priority knowledge gaps in current speciated knowledge.
- Research Organization:
- Univ. of California, Berkeley, CA (United States)
- Sponsoring Organization:
- National Science Fund (NSF); USDOE Office of Science (SC), Biological and Environmental Research (BER)
- Grant/Contract Number:
- SC0011105; SC0020051
- OSTI ID:
- 1995728
- Journal Information:
- Environmental Science and Technology, Journal Name: Environmental Science and Technology Journal Issue: 15 Vol. 57; ISSN 0013-936X
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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OSTI ID:1593306