Influence of urban pollution on the production of organic particulate matter from isoprene epoxydiols in central Amazonia
Journal Article
·
· Atmospheric Chemistry and Physics (Online)
more »
- Harvard Univ., Cambridge, MA (United States)
- Univ. of Colorado, Boulder, CO (United States)
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Univ. of California, Berkeley, CA (United States); Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
- Univ. of California, Berkeley, CA (United States)
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- Univ. de Sao Paulo, Sao Paulo (Brazil); Univ. Blaise Pascal, Aubiere (France)
- Univ. de Sao Paulo, Sao Paulo (Brazil)
- Instituto Nacional de Pesquisas da Amazonia, Amazonas (Brazil)
- Univ. do Estado do Amazonas, Amazonas (Brazil)
- The Univ. of North Carolina, Chapel Hill, NC (United States)
The atmospheric chemistry of isoprene contributes to the production of a substantial mass fraction of the particulate matter (PM) over tropical forests. Isoprene epoxydiols (IEPOX) produced in the gas phase by the oxidation of isoprene under HO2-dominant conditions are subsequently taken up by particles, thereby leading to production of secondary organic PM. The present study investigates possible perturbations to this pathway by urban pollution. The measurement site in central Amazonia was located 4 to 6 h downwind of Manaus, Brazil. Measurements took place from February through March 2014 of the wet season, as part of the GoAmazon2014/5 experiment. Mass spectra of organic PM collected with an Aerodyne Aerosol Mass Spectrometer were analyzed by positive-matrix factorization. One resolved statistical factor ("IEPOX-SOA factor") was associated with PM production by the IEPOX pathway. The IEPOX-SOA factor loadings correlated with independently measured mass concentrations of tracers of IEPOX-derived PM, namely C5-alkene triols and 2-methyltetrols (R = 0.96 and 0.78, respectively). The factor loading, as well as the ratio f of the loading to organic PM mass concentration, decreased under polluted compared to background conditions. For an increase in NOy concentration from 0.5 to 2 ppb, the factor loading and f decreased by two to three fold. Overall, sulfate concentration explained 37 % of the variability in the factor loading. After segregation of factor loading into subsets based on NOy concentration, the sulfate concentration explained up to 75 % of the variability. Considering both factors, the data sets show that the suppressing effects of increased NO concentrations dominated over the enhancing effects of higher sulfate concentrations. Furthermore, the pollution from Manaus elevated NOy concentrations more significantly than sulfate concentrations relative to background conditions. In this light, increased emissions of nitrogen oxides, as anticipated for some scenarios of Amazonian economic development, could significantly alter pathways of PM production that presently prevail over the tropical forest, implying changes to air quality and regional climate.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1363989
- Report Number(s):
- PNNL-SA--125341; KP1701000
- Journal Information:
- Atmospheric Chemistry and Physics (Online), Journal Name: Atmospheric Chemistry and Physics (Online) Journal Issue: 11 Vol. 17; ISSN 1680-7324
- Publisher:
- European Geosciences UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Influence of urban pollution on the production of organic particulate matter from isoprene epoxydiols in central Amazonia
Observationally Constrained Modeling of the Reactive Uptake of Isoprene-Derived Epoxydiols under Elevated Relative Humidity and Varying Acidity of Seed Aerosol Conditions
Effect of Organic Coatings, Humidity and Aerosol Acidity on Multiphase Chemistry of Isoprene Epoxydiols
Journal Article
·
Mon Jun 05 20:00:00 EDT 2017
· Atmospheric Chemistry and Physics: Discussions
·
OSTI ID:1341692
Observationally Constrained Modeling of the Reactive Uptake of Isoprene-Derived Epoxydiols under Elevated Relative Humidity and Varying Acidity of Seed Aerosol Conditions
Journal Article
·
Tue Mar 28 20:00:00 EDT 2023
· ACS Earth and Space Chemistry
·
OSTI ID:1970743
Effect of Organic Coatings, Humidity and Aerosol Acidity on Multiphase Chemistry of Isoprene Epoxydiols
Journal Article
·
Tue Jun 07 00:00:00 EDT 2016
· Environmental Science and Technology
·
OSTI ID:1324908