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Heterogeneous N 2 O 5 Uptake During Winter: Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of Current Parameterizations
Author(s) -
McDuffie Erin E.,
Fibiger Dorothy L.,
Dubé William P.,
LopezHilfiker Felipe,
Lee Ben H.,
Thornton Joel A.,
Shah Viral,
Jaeglé Lyatt,
Guo Hongyu,
Weber Rodney J.,
Michael Reeves J.,
Weinheimer Andrew J.,
Schroder Jason C.,
CampuzanoJost Pedro,
Jimenez Jose L.,
Dibb Jack E.,
Veres Patrick,
Ebben Carly,
Sparks Tamara L.,
Wooldridge Paul J.,
Cohen Ronald C.,
Hornbrook Rebecca S.,
Apel Eric C.,
Campos Teresa,
Hall Samuel R.,
Ullmann Kirk,
Brown Steven S.
Publication year - 2018
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2018jd028336
Subject(s) - aerosol , chemical transport model , troposphere , nitrate , atmospheric sciences , chemistry , mixing ratio , environmental science , meteorology , physics , organic chemistry
Nocturnal dinitrogen pentoxide (N 2 O 5 ) heterogeneous chemistry impacts regional air quality and the distribution and lifetime of tropospheric oxidants. Formed from the oxidation of nitrogen oxides, N 2 O 5 is heterogeneously lost to aerosol with a highly variable reaction probability, γ (N 2 O 5 ), dependent on aerosol composition and ambient conditions. Reaction products include soluble nitrate (HNO 3 or NO 3 − ) and nitryl chloride (ClNO 2 ). We report the first‐ever derivations of γ (N 2 O 5 ) from ambient wintertime aircraft measurements in the critically important nocturnal residual boundary layer. Box modeling of the 2015 Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign over the eastern United States derived 2,876 individual γ (N 2 O 5 ) values with a median value of 0.0143 and range of 2 × 10 −5 to 0.1751. WINTER γ (N 2 O 5 ) values exhibited the strongest correlation with aerosol water content, but weak correlations with other variables, such as aerosol nitrate and organics, suggesting a complex, nonlinear dependence on multiple factors, or an additional dependence on a nonobserved factor. This factor may be related to aerosol phase, morphology (i.e., core shell), or mixing state, none of which are commonly measured during aircraft field studies. Despite general agreement with previous laboratory observations, comparison of WINTER data with 14 literature parameterizations (used to predict γ (N 2 O 5 ) in chemical transport models) confirms that none of the current methods reproduce the full range of γ (N 2 O 5 ) values. Nine reproduce the WINTER median within a factor of 2. Presented here is the first field‐based, empirical parameterization of γ (N 2 O 5 ), fit to WINTER data, based on the functional form of previous parameterizations.