% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Schumann:841587,
      author       = {Schumann, Ulrich and Kiemle, Christoph and Schlager, Hans
                      and Weigel, Ralf and Borrmann, Stephan and $D\&apos$ and
                      Amato, Francesco and Krämer, Martina and Matthey, Renaud
                      and Protat, Alain and Voigt, Christiane and Volk, C.
                      Michael},
      title        = {{L}ong-lived contrails and convective cirrus above the
                      tropical tropopause},
      journal      = {Atmospheric chemistry and physics},
      volume       = {17},
      number       = {3},
      issn         = {1680-7324},
      address      = {Katlenburg-Lindau},
      publisher    = {EGU},
      reportid     = {FZJ-2017-08625},
      pages        = {2311 - 2346},
      year         = {2017},
      abstract     = {This study has two objectives: (1) it characterizes
                      contrails at very low temperatures and (2) it discusses
                      convective cirrus in which the contrails occurred. (1)
                      Long-lived contrails and cirrus from overshooting convection
                      are investigated above the tropical tropopause at low
                      temperatures down to −88 °C from measurements with the
                      Russian high-altitude research aircraft M-55 "Geophysica",
                      as well as related observations during the SCOUT-O3 field
                      experiment near Darwin, Australia, in 2005. A contrail was
                      observed to persist below ice saturation at low temperatures
                      and low turbulence in the stratosphere for nearly 1 h. The
                      contrail occurred downwind of the decaying convective system
                      "Hector" of 16 November 2005. The upper part of the contrail
                      formed at 19 km altitude in the tropical lower
                      stratosphere at $∼ 60 \%$ relative humidity over ice
                      at −82 °C. The ∼ 1 h lifetime is explained by
                      engine water emissions, slightly enhanced humidity from
                      Hector, low temperature, low turbulence, and possibly nitric
                      acid hydrate formation. The long persistence suggests large
                      contrail coverage in case of a potential future increase of
                      air traffic in the lower stratosphere. (2) Cirrus observed
                      above the strongly convective Hector cloud on 30 November
                      2005 was previously interpreted as cirrus from overshooting
                      convection. Here we show that parts of the cirrus were
                      caused by contrails or are mixtures of convective and
                      contrail cirrus. The in situ data together with data from an
                      upward-looking lidar on the German research aircraft
                      "Falcon", the CPOL radar near Darwin, and NOAA-AVHRR
                      satellites provide a sufficiently complete picture to
                      distinguish between contrail and convective cirrus parts.
                      Plume positions are estimated based on measured or analyzed
                      wind and parameterized wake vortex descent. Most of the
                      non-volatile aerosol measured over Hector is traceable to
                      aircraft emissions. Exhaust emission indices are derived
                      from a self-match experiment of the Geophysica in the polar
                      stratosphere in 2010. The number of ice particles in the
                      contrails is less than $1 \%$ of the number of
                      non-volatile aerosol particles, possibly because of
                      sublimation losses and undetected very small ice particles.
                      The radar data show that the ice water content in convective
                      overshoots is far higher than measured along the flight
                      path. These findings add insight into overshooting
                      convection and are of relevance with respect to hydration of
                      the lower stratosphere.},
      cin          = {IEK-7},
      ddc          = {550},
      cid          = {I:(DE-Juel1)IEK-7-20101013},
      pnm          = {244 - Composition and dynamics of the upper troposphere and
                      middle atmosphere (POF3-244)},
      pid          = {G:(DE-HGF)POF3-244},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000395118000006},
      doi          = {10.5194/acp-17-2311-2017},
      url          = {https://juser.fz-juelich.de/record/841587},
}