Large-Scale Nitrogen Oxide Plumes in the Tropopause Region and Implications for Ozone
Dominik Brunner,
Johannes Staehelin,
*
Dominique Jeker
Continuous measurements of nitrogen oxide and ozone were performed
from a commercial airliner during 1 year at cruising altitudes below
and above the tropopause. The upper tropospheric nitrogen oxides
distribution was found to be strongly influenced by large-scale plumes
extending about 100 to 1300 kilometers along the flight track. The
plumes were frequently observed downwind of thunderstorms and frontal
systems, which most probably caused upward transport of polluted air
from the continental boundary layer or nitrogen oxide production in
lightning strokes, or both. Particularly in summer, average ozone
concentrations in the plumes were enhanced compared to the tropospheric
background levels.
D. Brunner, Atmospheric Composition Research Division, Royal
Netherlands Meteorological Institute, 3730 AE De Bilt, Netherlands. J. Staehelin and D. Jeker, Institute for Atmospheric Science, Swiss
Federal Institute of Technology, ETH Hoenggerberg HPP, CH-8093 Zurich,
Switzerland.
*
To whom correspondence should be addressed. E-mail:
staehelin{at}atmos.umnw.ethz.ch
