CaltechAUTHORS
Published March 10, 2016 | Version Supplemental Material
Journal Article Open

Observational Constraints on the Oxidation of NO_x in the Upper Troposphere

Creators

  • 1. ROR icon University of California, Berkeley
  • 2. ROR icon Pennsylvania State University
  • 3. ROR icon University of Colorado Boulder
  • 4. ROR icon California Institute of Technology
  • 5. ROR icon University of New Hampshire
  • 6. ROR icon National Center for Atmospheric Research
  • 7. ROR icon Georgia Institute of Technology
  • 8. ROR icon National Oceanic and Atmospheric Administration
  • 9. ROR icon Oak Ridge Associated Universities
  • 10. ROR icon Earth System Research Laboratory
  • 11. ROR icon Air Resources Laboratory
  • 12. ROR icon Universität Innsbruck

Abstract

NO_x (NO_x ≡ NO + NO_2) regulates O_3 and HO_x (HO_x ≡ OH + HO_2) concentrations in the upper troposphere. In the laboratory, it is difficult to measure rates and branching ratios of the chemical reactions affecting NO_x at the low temperatures and pressures characteristic of the upper troposphere, making direct measurements in the atmosphere especially useful. We report quasi-Lagrangian observations of the chemical evolution of an air parcel following a lightning event that results in high NO_x concentrations. These quasi-Lagrangian measurements obtained during the Deep Convective Clouds and Chemistry experiment are used to characterize the daytime rates for conversion of NOx to different peroxy nitrates, the sum of alkyl and multifunctional nitrates, and HNO_3. We infer the following production rate constants [in (cm^3/molecule)/s] at 225 K and 230 hPa: 7.2(±5.7) × 10^(–12) (CH_3O_2NO_2), 5.1(±3.1) × 10^(–13) (HO_2NO_2), 1.3(±0.8) × 10^(–11) (PAN), 7.3(±3.4) × 10^(–12) (PPN), and 6.2(±2.9) × 10^(–12) (HNO_3). The HNO_3 and HO_2NO_2 rates are ∼30–50% lower than currently recommended whereas the other rates are consistent with current recommendations to within ±30%. The analysis indicates that HNO_3 production from the HO_2 and NO reaction (if any) must be accompanied by a slower rate for the reaction of OH with NO_2, keeping the total combined rate for the two processes at the rate reported for HNO_3 production above.

Additional Information

© 2015 American Chemical Society. Received 11 August 2015; published online 17 November 2015; published in print 10 March 2016. BAN was supported by the National Science Foundation Graduate Research Fellowship under grant no. DGE 1106400. BAN, CG, PWJ, and RCC acknowledge funding support from NASA (NNX12AB79G). PTR-MS measurements aboard the NASA DC-8 were supported by the Austrian Federal Ministry for Transport, Innovation and Technology (bmvit) through the Austrian Space Applications Programme (ASAP) of the Austrian Research Promotion Agency (FFG). TM was supported by an appointment to the NASA Postdoctoral Program at the Langley Research Center, administered by Oak Ridge Associated Universities through a contract with NASA. JDC and POW acknowledge funding support from NASA (NNX12AC06G and NNX14AP46G). PCJ and JLJ acknowledge funding form NASA (NNX12AC03G and NNX15AH33A). JD and ES acknowledge funding from NASA (NNX12AB80G). BAN would like to thank Joshua L. Laughner in his assistance in setting up and running the GEOS-Chem model. The authors also want to thank the ground and flight crews of the DC-8 and the DC3 science team. Finally, the authors want to thank Donald Blake for the use of the whole air sampler measurements, Glenn Diskin for the use of the CH_4 observations, and the reviewers for their constructive and thoughtful comments.

Attached Files

Supplemental Material - jp5b07824_si_001.pdf

Files

jp5b07824_si_001.pdf

Files (571.5 kB)

Name Size
md5:93f288bec91d7f8ad368d76171d7c2ec
571.5 kB Preview Download

Additional details

Identifiers

Eprint ID
66026
DOI
10.1021/acs.jpca.5b07824
Resolver ID
CaltechAUTHORS:20160408-121404439

Related works

Describes
10.1021/acs.jpca.5b07824 (DOI)

Funding

NSF Graduate Research Fellowship
DGE 1106400
NASA
NNX12AB79G
Bundesministerium für Verkehr, Innovation und Technologie (BMVIT)
Österreichische Forschungsförderungsgesellschaft (FFG)
NASA Postdoctoral Program
NASA
NNX12AC06G
NASA
NNX14AP46G
NASA
NNX12AC03G
NASA
NNX15AH33A
NASA
NNX12AB80G

Dates

Created
2016-04-15
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS)