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@ARTICLE{Weigel:156071,
      author       = {Weigel, R and Volk, C. M. and Kandler, K. and Hösen, E.
                      and Günther, Gebhard and Vogel, Bärbel and Grooss,
                      Jens-Uwe and Khaykin, S. and Belyaev, G. V. and Borrmann,
                      S.},
      title        = {{E}nhancements of the refractory submicron aerosol fraction
                      in the {A}rctic polar vortex: feature or exception ?},
      journal      = {Atmospheric chemistry and physics / Discussions},
      volume       = {14},
      issn         = {1680-7367},
      address      = {Katlenburg-Lindau},
      publisher    = {EGU},
      reportid     = {FZJ-2014-04954},
      pages        = {9849-9901},
      year         = {2014},
      abstract     = {In situ measurements with a 4-channel stratospheric
                      condensation particle counter (CPC) were conducted at up to
                      20 km altitude on board the aircraft M-55 Geophysica from
                      Kiruna, Sweden, in January through March (EUPLEX 2003;
                      RECONCILE 2010) and in December (ESSenCe, 2011). During all
                      campaigns air masses from the upper stratosphere and
                      mesosphere were subsiding inside the Arctic winter vortex,
                      thus transporting refractory aerosol into the lower
                      stratosphere (Θ<500 K) by vertical dispersion. The strength
                      and extent of this downward transport varied between the
                      years depending on the dynamical evolution of the vortex.
                      Inside the vortex and at altitudes of potential temperatures
                      Θ ≥ 450 K as many as eight of eleven particles per cm3
                      contained refractory material, thermally stable residuals
                      with diameters from 10 nm to a few μm which endure heat
                      exposure of 250 °C. Particle mixing ratios (up to 150
                      refractory particles per milligram of air) and fractions of
                      non-volatile particles (up to $75\%$ of totally detected
                      particles) reach highest values in air masses with lowest
                      content of nitrous oxide (N2O, down to 70 nmol mol−1).
                      This indicates that refractory aerosol originates from the
                      upper stratosphere or the mesosphere. From mixing ratios of
                      the long lived tracer N2O (simultaneously measured in situ)
                      an empirical index was derived which serves to differentiate
                      air masses according to their origin from inside the vortex,
                      the vortex edge region, and outside the vortex. Previously,
                      observed high fractions of refractory submicron aerosol in
                      the 2003 Arctic vortex were ascribed to unusually strong
                      subsidence during that winter. Measurements under perturbed
                      vortex conditions in 2010 and during early winter in
                      December 2011, however, revealed similarly high values.
                      Thus, the abundance of refractory aerosol at high levels
                      appears to be a feature rather than the exception for the
                      Arctic vortices. During December, the import from aloft into
                      the lower stratosphere appears to be developing; thereafter
                      the abundance of refractory aerosol inside the vortex
                      reaches its highest levels until March. A measurement-based
                      estimate of the total mass of refractory aerosol inside the
                      vortex is provided for each campaign. Based on the derived
                      increase of particle mass in the lower stratospheric vortex
                      (100–67 hPa pressure altitude) on the order of 32 × 106
                      kg between early and late winter and assuming a mesospheric
                      origin, we estimate the total mass of mesospheric particles
                      deposited in the Arctic vortex and compare it to the
                      expected atmospheric influx of meteoritic material (110 ±
                      55 × 103 kg per day). Such estimates at present still hold
                      considerable uncertainties which are discussed in detail.
                      Nevertheless, the results strongly suggest that the Arctic
                      vortex easily achieves the drainage of all meteoric material
                      deposited on the upper atmosphere.},
      cin          = {IEK-7},
      ddc          = {550},
      cid          = {I:(DE-Juel1)IEK-7-20101013},
      pnm          = {234 - Composition and Dynamics of the Upper Troposphere and
                      Stratosphere (POF2-234)},
      pid          = {G:(DE-HGF)POF2-234},
      typ          = {PUB:(DE-HGF)16},
      doi          = {10.5194/acpd-14-9849-2014},
      url          = {https://juser.fz-juelich.de/record/156071},
}