Reactive nitrogen distribution and partitioning in the North American troposphere and lowermost stratosphere

Authors

H B. Singh, NASA
L Salas, NASA
D Herlth, NASA
R Koyler, NASA
M A. Avery, NASAFollow
J H. Crawford, Georgia Institute of TechnologyFollow
R B. Pierce, NOAA
Glen Sachse, National Institute of AerospaceFollow
D R. Blake, University of California, Irvine
Ronald C. Cohen, University of California - Berkeley
T H. Bertram, University of California - Berkeley
A E. Perring, University of California - BerkeleyFollow
Paul J. Wooldridge, University of California - Berkeley
Jack E. Dibb, University of New HampshireFollow
L Gregory Huey, Georgia Institute of Technology - Main Campus
R C. Hudman, Harvard University
S Turquety, Harvard UniversityFollow
L K. Emmons, National Center for Atmospheric Research
F Flocke, National Center for Atmospheric Research
Youhua Tang, University of Iowa
Gregory R. Carmichael, University of Iowa
Larry Horowitz, NOAA

Abstract

A comprehensive group of reactive nitrogen species (NO, NO₂, HNO₃, HO₂NO₂, PANs, alkyl nitrates, and aerosol-NO₃⁻) were measured over North America during July/August 2004 from the NASA DC-8 platform (0.1–12 km). Nitrogen containing tracers of biomass combustion (HCN and CH₃CN) were also measured along with a host of other gaseous (CO, VOC, OVOC, halocarbon) and aerosol tracers. Clean background air as well as air with influences from biogenic emissions, anthropogenic pollution, biomass combustion, convection, lightning, and the stratosphere was sampled over the continental United States, the Atlantic, and the Pacific. The North American upper troposphere (UT) was found to be greatly influenced by both lightning NO_x and surface pollution lofted via convection and contained elevated concentrations of PAN, ozone, hydrocarbons, and NO_x. Observational data suggest that lightning was a far greater contributor to NO_x in the UT than previously believed. PAN provided a dominant reservoir of reactive nitrogen in the UT while nitric acid dominated in the lower troposphere (LT). Peroxynitric acid (HO₂NO₂) was present in sizable concentrations peaking at around 8 km. Aerosol nitrate appeared to be mostly contained in large soil based particles in the LT. Plumes from Alaskan fires contained large amounts of PAN and aerosol nitrate but little enhancement in ozone. A comparison of observed data with simulations from four 3-D models shows significant differences between observations and models as well as among models. We investigate the partitioning and interplay of the reactive nitrogen species within characteristic air masses and further examine their role in ozone formation.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

6-27-2007

Journal Title

Journal of Geophysical Research

Publisher

Wiley

Digital Object Identifier (DOI)

10.1029/2006JD007664

Document Type

Article

Recommended Citation

Singh, H. B., et al. (2007), Reactive nitrogen distribution and partitioning in the North American troposphere and lowermost stratosphere, J. Geophys. Res., 112, D12S04, doi:10.1029/2006JD007664.

Rights

Copyright 2007 by the American Geophysical Union.