Reactive nitrogen in Asian continental outflow over the western Pacific: Results from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission

Authors

R. Talbot, University of New HampshireFollow
Jack E. Dibb, University of New HampshireFollow
Eric Scheuer, University of New Hampshire - Main CampusFollow
Garry Seid, University of New Hampshire - Main Campus
R. S. Russo, University of New Hampshire
S T. Sandholm, Georgia Institute of Technology
D Tan, Georgia Institute of Technology - Main CampusFollow
H B. Singh, NASA
D R. Blake, University of California, Irvine
N J. Blake, University of California, IrvineFollow
Elliot Atlas, NCARFollow
G W. Sachse, NASA Langley Research CenterFollow
C. Jordan, University of New Hampshire
Melody A. Avery, NASAFollow

Abstract

We present here results for reactive nitrogen species measured aboard the NASA DC-8 aircraft during the Transport and Chemical Evolution over the Pacific (TRACE-P) mission. The large-scale distributions total reactive nitrogen (NO_y,sum = NO + NO₂ + HNO₃ + PAN + C₁–C₅alkyl nitrates) and O₃ and CO were better defined in the boundary layer with significant degradation of the relationships as altitude increased. Typically, NO_y,sum was enhanced over background levels of ∼260 pptv by 20-to-30-fold. The ratio C₂H₂/CO had values of 1–4 at altitudes up to 10 km and as far eastward as 150°E, implying significant vertical mixing of air parcels followed by rapid advection across the Pacific. Analysis air parcels originating from five principal Asian source regions showed that HNO₃ and PAN dominated NO_y,sum. Correlations of NO_y,sum with C₂Cl₄ (urban tracer) were not well defined in any of the source regions, and they were only slightly better with CH₃Cl (biomass tracer). Air parcels over the western Pacific contained a complex mixture of emission sources that are not easily resolvable as shown by analysis of the Shanghai mega-city plume. It contained an intricate mixture of pollution emissions and exhibited the highest mixing ratios of NO_y,sum species observed during TRACE-P. Comparison of tropospheric chemistry between the earlier PEM-West B mission and the recent TRACE-P data showed that in the boundary layer significant increases in the mixing ratios of NO_y,sum species have occurred, but the middle and upper troposphere seems to have been affected minimally by increasing emissions on the Asian continent over the last 7 years.

Department

Earth Sciences, Earth Systems Research Center

Publication Date

10-27-2003

Journal Title

Journal of Geophysical Research

Publisher

Wiley

Digital Object Identifier (DOI)

10.1029/2002JD003129

Document Type

Article

Recommended Citation

Talbot, R., et al. (2003), Reactive nitrogen in Asian continental outflow over the western Pacific: Results from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission, J. Geophys. Res., 108, 8803, doi:10.1029/2002JD003129, D20.

Rights

Copyright 2003 by the American Geophysical Union.