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@ARTICLE{Hoffmann:834516,
      author       = {Hoffmann, Lars and Hertzog, Albert and Rössler, Thomas and
                      Stein, Olaf and Wu, Xue},
      title        = {{I}ntercomparison of meteorological analyses and
                      trajectories in the {A}ntarctic lower stratosphere with
                      {C}oncordiasi superpressure balloon observations},
      journal      = {Atmospheric chemistry and physics},
      volume       = {17},
      number       = {13},
      issn         = {1680-7324},
      address      = {Katlenburg-Lindau},
      publisher    = {EGU},
      reportid     = {FZJ-2017-04447},
      pages        = {8045 - 8061},
      year         = {2017},
      abstract     = {In this study we compared temperatures and horizontal winds
                      of meteorological analyses in the Antarctic lower
                      stratosphere, a region of the atmosphere that is of major
                      interest regarding chemistry and dynamics of the polar
                      vortex. The study covers the European Centre for
                      Medium-Range Weather Forecasts (ECMWF) operational analysis,
                      the ERA-Interim reanalysis, the Modern-Era Retrospective
                      analysis for Research and Applications version 1 and 2
                      (MERRA and MERRA-2), and the National Centers for
                      Environmental Prediction and National Center for Atmospheric
                      Research (NCEP/NCAR) reanalysis. The comparison was
                      performed with respect to long-duration observations from 19
                      superpressure balloon flights during the Concordiasi field
                      campaign in September 2010 to January 2011. Most of the
                      balloon measurements were conducted at altitudes of
                      17–18.5 km and latitudes of 60–85° S. We found that
                      large-scale state temperatures of the analyses have a mean
                      precision of 0.5–1.4 K and a warm bias of 0.4–2.1 K
                      with respect to the balloon data. Zonal and meridional winds
                      have a mean precision of 0.9–2.3 m s−1 and a bias
                      below ±0.5 m s−1. Standard deviations related to
                      small-scale fluctuations due to gravity waves are reproduced
                      at levels of $15–60 \%$ for temperature and
                      $30–60 \%$ for the horizontal winds. Considering the
                      fact that the balloon observations have been assimilated
                      into all analyses, except for NCEP/NCAR, notable differences
                      found here indicate that other observations, the forecast
                      models, and the data assimilation procedures have a
                      significant impact on the analyses as well. We also used the
                      balloon observations to evaluate trajectory calculations
                      with our new Lagrangian transport model Massive-Parallel
                      Trajectory Calculations (MPTRAC), where vertical motions of
                      simulated trajectories were nudged to pressure measurements
                      of the balloons. We found relative horizontal transport
                      deviations of $4–12 \%$ and error growth rates of
                      60–170 km day−1 for 15-day trajectories. Dispersion
                      simulations revealed some difficulties with the
                      representation of subgrid-scale wind fluctuations in MPTRAC,
                      as the spread of air parcels simulated with different
                      analyses was not consistent. However, although case studies
                      suggest that the accuracy of trajectory calculations is
                      influenced by meteorological complexity, diffusion generally
                      does not contribute significantly to transport deviations in
                      our analysis. Overall, evaluation results are satisfactory
                      and compare well to earlier studies using superpressure
                      balloon observations.},
      cin          = {JSC},
      ddc          = {550},
      cid          = {I:(DE-Juel1)JSC-20090406},
      pnm          = {511 - Computational Science and Mathematical Methods
                      (POF3-511)},
      pid          = {G:(DE-HGF)POF3-511},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:000404773700002},
      doi          = {10.5194/acp-17-8045-2017},
      url          = {https://juser.fz-juelich.de/record/834516},
}