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The prevalence of meteoric-sulphuric particles within the stratospheric aerosol layer
  • +16
  • Graham Mann,
  • James Brooke,
  • Kamalika Sengupta,
  • Lauren Marshall,
  • Sandip Dhomse,
  • Wuhu Feng,
  • Ken Carslaw,
  • Charles Bardeen,
  • Nicolas Bellouin,
  • M Dalvi,
  • Colin Johnson,
  • Luke Abraham,
  • Samuel Remy,
  • Vincent Huijnen,
  • Simon Chabrillat,
  • Zak Kipling,
  • Terry Deshler,
  • Larry Thomason,
  • John Plane
Graham Mann
University of Leeds

Corresponding Author:g.w.mann@leeds.ac.uk

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James Brooke
University of Leeds
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Kamalika Sengupta
University of Leeds
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Lauren Marshall
University of Cambridge
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Sandip Dhomse
University of Leeds
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Wuhu Feng
University of Leeds
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Ken Carslaw
University of Leeds
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Charles Bardeen
National Center for Atmospheric Research
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Nicolas Bellouin
University of Reading
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M Dalvi
Met Office
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Colin Johnson
Met Office Hadley center for Climate Change
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Luke Abraham
University of Cambridge
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Samuel Remy
HYGEOS research consultancy
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Vincent Huijnen
Royal Netherlands Meteorological Institute
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Simon Chabrillat
Royal Belgian Institute for Space Aeronomy
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Zak Kipling
European Centre for Medium-Range Weather Forecasts
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Terry Deshler
University of Wyoming
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Larry Thomason
NASA Langley Research Center
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John Plane
University of Leeds
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Abstract

The widespread presence of meteoric smoke particles (MSPs) within a distinct class of stratospheric aerosol particles has become clear from in-situ measurements in the Arctic, Antarctic and at mid-latitudes. We apply an adapted version of the interactive stratosphere aerosol configuration of the composition-climate model UM-UKCA, to predict the global distribution of meteoric-sulphuric particles nucleated heterogeneously on MSP cores. We compare the UM-UKCA results to new MSP-sulphuric simulations with the European stratosphere-troposphere chemistry-aerosol modelling system IFS-CB05-BASCOE-GLOMAP. The simulations show a strong seasonal cycle in meteoric-sulphuric particle abundance results from the winter-time source of MSPs transported down into the stratosphere in the polar vortex. Coagulation during downward transport sees high latitude MSP concentrations reduce from ~500 per cm3 at 40km to ~20 per cm3 at 25km, the uppermost extent of the stratospheric aerosol particle layer (the Junge layer). Once within the Junge layer’s supersaturated environment, meteoric-sulphuric particles form readily on the MSP cores, growing to 50-70nm dry-diameter (Dp) at 20-25km. Further inter-particle coagulation between these non-volatile particles reduces their number to 1-5 per cc at 15-20km, particle sizes there larger, at Dp ~100nm. The model predicts meteoric-sulphurics in high-latitude winter comprise >90% of Dp > 10nm particles above 25km, reducing to ~40% at 20km, and ~10% at 15km. These non-volatile particle fractions are slightly less than measured from high-altitude aircraft in the lowermost Arctic stratosphere (Curtius et al., 2005; Weigel et al., 2014), and consistent with mid-latitude aircraft measurements of lower stratospheric aerosol composition (Murphy et al., 1998), total particle concentrations also matching in-situ balloon measurements from Wyoming (Campbell and Deshler, 2014). The MSP-sulphuric interactions also improve agreement with SAGE-II observed stratospheric aerosol extinction in the quiescent 1998-2002 period. Simulations with a factor-8-elevated MSP input form more Dp>10nm meteoric-sulphurics, but the increased number sees fewer growing to Dp ~100nm, the increased MSPs reducing the stratospheric aerosol layer’s light extinction.