NOx lifetime and NOy partitioning during WINTER

Authors

Hannah S. Kenagy, University of California
Tamara L. Sparks, University of California
Carlena J. Ebben, University of California
Paul J. Wooldrige, University of California
Felipe D. Lopez-Hilfiker, University of Washington
Ben H. Lee, University of Washington
Joel A. Thornton, University of Washington
Erin E. McDuffie, National Oceanic and Atmospheric Administration
Dorothy L. Fibiger, National Oceanic and Atmospheric Administration
Steven S. Brown, National Oceanic and Atmospheric Administration
Denise D. Montzka, National Center for Atmospheric Research
Andrew J. Weinheimer, National Center for Atmospheric Research
Jason C. Schroder, University of Colorado
Pedro Campuzano-Jost, University of Colorado
Douglas A. Day, University of Colorado
Jose L. Jimenez, University of Colorado
Jack E. Dibb, University of New HampshireFollow
Teresa Campos, National Center for Atmospheric Research
Viral Shah, University of Washington
Lyatt Jaegle, University of Washington
Ronald C. Cohen, University of California

Abstract

Although urban NOx lifetimes have been examined extensively during summertime conditions, wintertime NOx chemistry has been comparatively less studied. We use measurements of NOx and its oxidation products from the aircraft-based WINTER (Wintertime INvestigation of Transport, Emissions, and Reactivity) experiment over the northeastern United States during February–March 2015 to describe the NOx lifetime during conditions when days are shorter, actinic flux is reduced, and temperatures are colder. By analyzing regional outflow from the East Coast, we show that NOx is long lived during the winter, with a longer daytime lifetime (29 hr) than nighttime lifetime (6.3 hr). We demonstrate that wintertime NOx emissions have an overall lifetime controlled by the nighttime conversion of NOx to nitric acid (HNO3) via N2O5 heterogeneous chemistry, and we discuss constraints on the rates of NOx conversion to HNO3. Additionally, analysis of the nighttime Ox budget suggests that approximately 15% of O3 is lost overnight through N2O5 production and subsequent reaction with aerosol to form HNO3.

Department

Earth Systems Research Center

Publication Date

8-1-2018

Journal Title

JGR: Atmospheres

Publisher

AGU

Digital Object Identifier (DOI)

https://dx.doi.org/10.1029/2018JD028736

Document Type

Article

Recommended Citation

Kenagy, H. S., T. L. Sparks, C. J. Ebben, P. J. Wooldridge, F. D. Lopez-Hilfiker, B. H. Lee, J. A. Thornton, E. E. McDuffie, D. L. Fibiger, S. S. Brown, D. D. Montzka, A. J. Weinheimer, J. C. Schroder, P. Campuzano-Jost, D. A. Day, J. L. Jimenez, J. E. Dibb, T. Campos, V. Shah, L. Jaegle, and R. C. Cohen (2018), NOx lifetime and NOy partitioning during WINTER, Journal of Geophysical Research: Atmospheres, 123. https:doi.org/10.1029/2018JD028736.