% 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{Poshyvailo:858099,
      author       = {Poshyvailo, Liubov and Müller, Rolf and Konopka, Paul and
                      Günther, Gebhard and Riese, Martin and Podglajen, Aurelien
                      and Ploeger, Felix},
      title        = {{S}ensitivities of modelled water vapour in the lower
                      stratosphere: temperature uncertainty, effects of horizontal
                      transport and small-scale mixing},
      journal      = {Atmospheric chemistry and physics},
      volume       = {18},
      number       = {12},
      issn         = {1680-7324},
      address      = {Katlenburg-Lindau},
      publisher    = {EGU},
      reportid     = {FZJ-2018-07017},
      pages        = {8505 - 8527},
      year         = {2018},
      abstract     = {Water vapour (H2O) in the upper troposphere and lower
                      stratosphere (UTLS) has a significant role for global
                      radiation. A realistic representation of H2O is therefore
                      critical for accurate climate model predictions of future
                      climate change. In this paper we investigate the effects of
                      current uncertainties in tropopause temperature, horizontal
                      transport and small-scale mixing on simulated H2O in the
                      lower stratosphere (LS).To assess the sensitivities of
                      simulated H2O, we use the Chemical Lagrangian Model of the
                      Stratosphere (CLaMS). First, we examine CLaMS, which is
                      driven by two reanalyses, from the European Centre of
                      Medium-Range Weather Forecasts (ECMWF) ERA-Interim and the
                      Japanese 55-year Reanalysis (JRA-55), to investigate the
                      robustness with respect to the meteorological dataset.
                      Second, we carry out CLaMS simulations with transport
                      barriers along latitude circles (at the Equator, 15 and
                      35°N/S) to assess the effects of horizontal transport.
                      Third, we vary the strength of parametrized small-scale
                      mixing in CLaMS.Our results show significant differences
                      (about 0.5ppmv) in simulated stratospheric H2O due to
                      uncertainties in the tropical tropopause temperatures
                      between the two reanalysis datasets, JRA-55 and ERA-Interim.
                      The JRA-55 based simulation is significantly moister when
                      compared to ERA-Interim, due to a warmer tropical tropopause
                      (approximately 2K). The transport barrier experiments
                      demonstrate that the Northern Hemisphere (NH) subtropics
                      have a strong moistening effect on global stratospheric H2O.
                      The comparison of tropical entry H2O from the sensitivity
                      15°N/S barrier simulation and the reference case shows
                      differences of up to around 1ppmv. Interhemispheric exchange
                      shows only a very weak effect on stratospheric H2O.
                      Small-scale mixing mainly increases
                      troposphere–stratosphere exchange, causing an enhancement
                      of stratospheric H2O, particularly along the subtropical
                      jets in the summer hemisphere and in the NH monsoon regions.
                      In particular, the Asian and American monsoon systems during
                      a boreal summer appear to be regions especially sensitive to
                      changes in small-scale mixing, which appears crucial for
                      controlling the moisture anomalies in the monsoon UTLS. For
                      the sensitivity simulation with varied mixing strength,
                      differences in tropical entry H2O between the weak and
                      strong mixing cases amount to about 1ppmv, with small-scale
                      mixing enhancing H2O in the LS.The sensitivity studies
                      presented here provide new insights into the leading
                      processes that control stratospheric H2O, which are
                      important for assessing and improving climate model
                      projections.},
      cin          = {IEK-7 / JARA-HPC},
      ddc          = {550},
      cid          = {I:(DE-Juel1)IEK-7-20101013 / $I:(DE-82)080012_20140620$},
      pnm          = {244 - Composition and dynamics of the upper troposphere and
                      middle atmosphere (POF3-244) / Chemisches Lagrangesches
                      Modell der Stratosphäre (CLaMS) $(jicg11_20090701)$},
      pid          = {G:(DE-HGF)POF3-244 / $G:(DE-Juel1)jicg11_20090701$},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000435484300003},
      doi          = {10.5194/acp-18-8505-2018},
      url          = {https://juser.fz-juelich.de/record/858099},
}