The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water
Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmospher...
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2018-01-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/1171/2018/acp-18-1171-2018.pdf |
| _version_ | 1818539309451444224 |
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| author | M. M. H. El-Sayed D. L. Ortiz-Montalvo C. J. Hennigan |
| author_facet | M. M. H. El-Sayed D. L. Ortiz-Montalvo C. J. Hennigan |
| author_sort | M. M. H. El-Sayed |
| collection | DOAJ |
| description | Isoprene oxidation produces water-soluble organic gases capable of
partitioning to aerosol liquid water. The formation of secondary organic
aerosols through such aqueous pathways (aqSOA) can take place either
reversibly or irreversibly; however, the split between these fractions in the
atmosphere is highly uncertain. The aim of this study was to characterize the
reversibility of aqSOA formed from isoprene at a location in the eastern
United States under substantial influence from both anthropogenic and
biogenic emissions. The reversible and irreversible uptake of water-soluble
organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using
measurements of particulate water-soluble organic carbon (WSOC<sub>p</sub>)
in alternating dry and ambient configurations. WSOC<sub>p</sub> evaporation
with drying was observed systematically throughout the late spring and
summer, indicating reversible aqSOA formation during these times. We show
through time lag analyses that WSOC<sub>p</sub> concentrations, including
the WSOC<sub>p</sub> that evaporates with drying, peak 6 to 11 h after
isoprene concentrations, with maxima at a time lag of 9 h. The absolute
reversible aqSOA concentrations, as well as the relative amount of reversible
aqSOA, increased with decreasing NO<sub><i>x</i></sub> ∕ isoprene ratios, suggesting
that isoprene epoxydiol (IEPOX) or other low-NO<sub><i>x</i></sub> oxidation products may
be responsible for these effects. The observed relationships with NO<sub><i>x</i></sub>
and isoprene suggest that this process occurs widely in the atmosphere, and
is likely more important in other locations characterized by higher isoprene
and/or lower NO<sub><i>x</i></sub> levels. This work underscores the importance of
accounting for both reversible and irreversible uptake of isoprene oxidation
products to aqueous particles. |
| first_indexed | 2024-12-11T21:40:21Z |
| format | Article |
| id | doaj.art-897a1d5ba8c84f03b438c1b4368e2da0 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-11T21:40:21Z |
| publishDate | 2018-01-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-897a1d5ba8c84f03b438c1b4368e2da02022-12-22T00:49:51ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242018-01-01181171118410.5194/acp-18-1171-2018The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol waterM. M. H. El-Sayed0D. L. Ortiz-Montalvo1C. J. Hennigan2Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, USANational Institute of Standards and Technology (NIST), Gaithersburg, MD, USADepartment of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, USAIsoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using measurements of particulate water-soluble organic carbon (WSOC<sub>p</sub>) in alternating dry and ambient configurations. WSOC<sub>p</sub> evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation during these times. We show through time lag analyses that WSOC<sub>p</sub> concentrations, including the WSOC<sub>p</sub> that evaporates with drying, peak 6 to 11 h after isoprene concentrations, with maxima at a time lag of 9 h. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NO<sub><i>x</i></sub> ∕ isoprene ratios, suggesting that isoprene epoxydiol (IEPOX) or other low-NO<sub><i>x</i></sub> oxidation products may be responsible for these effects. The observed relationships with NO<sub><i>x</i></sub> and isoprene suggest that this process occurs widely in the atmosphere, and is likely more important in other locations characterized by higher isoprene and/or lower NO<sub><i>x</i></sub> levels. This work underscores the importance of accounting for both reversible and irreversible uptake of isoprene oxidation products to aqueous particles.https://www.atmos-chem-phys.net/18/1171/2018/acp-18-1171-2018.pdf |
| spellingShingle | M. M. H. El-Sayed D. L. Ortiz-Montalvo C. J. Hennigan The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water Atmospheric Chemistry and Physics |
| title | The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| title_full | The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| title_fullStr | The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| title_full_unstemmed | The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| title_short | The effects of isoprene and NO<sub><i>x</i></sub> on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| title_sort | effects of isoprene and no sub i x i sub on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water |
| url | https://www.atmos-chem-phys.net/18/1171/2018/acp-18-1171-2018.pdf |
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