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@ARTICLE{Hoffmann:1009095,
      author       = {Hoffmann, Lars and Konopka, Paul and Clemens, Jan Heinrich
                      and Vogel, Bärbel},
      title        = {{L}agrangian transport simulations using the extreme
                      convection parameterization: an assessment for the {ECMWF}
                      reanalyses},
      journal      = {Atmospheric chemistry and physics},
      volume       = {23},
      number       = {13},
      issn         = {1680-7316},
      address      = {Katlenburg-Lindau},
      publisher    = {EGU},
      reportid     = {FZJ-2023-02634},
      pages        = {7589–7609},
      year         = {2023},
      abstract     = {Atmospheric convection plays a key role in tracer transport
                      from the planetary boundary layer to the free troposphere.
                      Lagrangian transport simulations driven by meteorological
                      fields from global models or reanalysis products, such as
                      the European Centre for Medium-Range Weather Forecasts'
                      (ECMWF's) ERA5 and ERA-Interim reanalysis, typically lack
                      proper explicit representations of convective updrafts and
                      downdrafts because of the limited spatiotemporal resolution
                      of the meteorology. Lagrangian transport simulations for the
                      troposphere can be improved by applying parameterizations to
                      better represent the effects of unresolved convective
                      transport in the global meteorological reanalyses. Here, we
                      implemented and assessed the effects of the extreme
                      convection parameterization (ECP) in the Massive-Parallel
                      Trajectory Calculations (MPTRAC) model. The ECP is
                      conceptually simple. It requires the convective available
                      potential energy (CAPE) and the height of the equilibrium
                      level (EL) as input parameters. Assuming that unresolved
                      convective events yield well-mixed vertical columns of air,
                      the ECP randomly redistributes the air parcels vertically
                      between the surface and the EL if CAPE is present. We
                      analyzed statistics of explicitly resolved and parameterized
                      convective updrafts and found that the frequencies of strong
                      updrafts due to the ECP, i.e., 20 K potential temperature
                      increase over 6 h or more, increase by 2 to 3 orders of
                      magnitude for ERA5 and 3 to 5 orders of magnitude for
                      ERA-Interim compared to the explicitly resolved updrafts. To
                      assess the effects of the ECP on tropospheric tracer
                      transport, we conducted transport simulations for the
                      artificial tracer e90, which is released globally near the
                      surface and which has a constant e-folding lifetime of
                      90 d throughout the atmosphere. The e90 simulations were
                      conducted for the year 2017 with both ERA5 and ERA-Interim.
                      Next to sensitivity tests on the choice of the CAPE
                      threshold, an important tuning parameter of the ECP, we
                      suggest a modification of the ECP method, i.e., to take into
                      account the convective inhibition (CIN) indicating the
                      presence of warm, stable layers that prevent convective
                      updrafts in the real atmosphere. While ERA5 has higher
                      spatiotemporal resolution and explicitly resolves more
                      convective updrafts than ERA-Interim, we found there is
                      still a need for both reanalyses to apply a convection
                      parameterization such as the ECP to better represent tracer
                      transport from the planetary boundary layer into the free
                      troposphere on the global scale.},
      cin          = {JSC / IEK-7 / CASA},
      ddc          = {550},
      cid          = {I:(DE-Juel1)JSC-20090406 / I:(DE-Juel1)IEK-7-20101013 /
                      I:(DE-Juel1)CASA-20230315},
      pnm          = {5111 - Domain-Specific Simulation $\&$ Data Life Cycle Labs
                      (SDLs) and Research Groups (POF4-511) / 2112 - Climate
                      Feedbacks (POF4-211)},
      pid          = {G:(DE-HGF)POF4-5111 / G:(DE-HGF)POF4-2112},
      typ          = {PUB:(DE-HGF)16},
      UT           = {WOS:001054196800001},
      doi          = {10.5194/acp-23-7589-2023},
      url          = {https://juser.fz-juelich.de/record/1009095},
}