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| Titel |
The prevalence of MSP-core sulphuric particles in the stratospheric Junge layer |
| VerfasserIn |
Graham Mann, James Brooke, John Plane, Sandip Dhomse, Wuhu Feng, Ryan Neely, Chuck Bardeen, Nicolas Bellouin, Mohit Dalvi, Colin Johnson, Luke Abraham |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250153810
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| Publikation (Nr.) |
 EGU/EGU2017-18833.pdf |
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| Zusammenfassung |
| 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 (Weigel et al., 2014; Curtius et al., 2005), Antarctic (Campbell and Deshler, 2014) and mid-latitudes (Murphy et al. 2013; Murphy et al., 1998). The key role such MSP inclusions play in enabling stratospheric aerosol particles to nucleate into polar stratospheric clouds (PSCs) has been established from microphysical PSC simulations (Hoyle et al., 2013; Engel et al., 2013) and space-borne lidar measurements (Pitts et al., 2011).
In this study, we apply the UM-UKCA stratosphere-troposphere composition-climate model with interactive modal aerosol microphysics (Dhomse et al., 2014) to assess the global distribution of these MSP-core sulphuric particles in the stratosphere. In our 80km top UM-UKCA model, we impose a monthly-varying MSP number and mass distribution based on separate simulations with the NCAR 120km top WACCM-CARMA model, which has sectional aerosol microphysics (e.g. Bardeen et al., 2008). In UM-UKCA, the MSP-core particles are tracked in a separate mode from the homogeneously nucleated particles, and the two different types of sulphuric particles both take up and evaporate off sulphuric acid vapour according to ambient conditions.
By comparing simulations particle concentrations to balloon-borne stratospheric aerosol measurements, we observationally constrain the MSP input into the upper atmosphere, and identify the treatment of H2SO4 photolysis as an important sensitivity in model predictions. We illustrate how the MSP-core sulphuric are not restricted to polar regions, but are prevalent at all latitudes, particularly in the upper part of the Junge layer. We show there is a steep vertical profile in particle morphology, the layer transitioning from being mostly homogeneously nucleated particles in the lower stratosphere to being mostly heterogeneously nucleated particles at the top.
Bardeen, C. G. et al. “Numerical simulations of the three-dimensional distribution of meteoric dust in the mesosphere and upper stratosphere”, J. Geophys. Res., 113, D17202, doi:10.1029/2007JD009515, 2008.
Campbell, P. and Deshler, T. “Condensation nuclei measurements in the midlatitude (1982–2012) and Antarctic (1986–2010) stratosphere between 20 and 35km” vol. 119, 137–152, doi:10.1002/2013JD019710
Curtius, J. et al. “Observations of meteoric material and implications for aerosol nucleation in the winter Arctic lower stratosphere derived from in situ particle measurements”, Atmos. Chem. Phys., 5, 3053–3069, 2005.
Dhomse, S. S. et al. “Aerosol microphysics simulations of the Mt. Pinatubo eruption with the UM-UKCA composition-climate model”, Atmos. Chem. Phys., 14, 11221–11246, 2014.
Engel, I. et al. “Arctic stratospheric dehydration – Part 2: Microphysical modelling”, Atmos. Chem. Phys., 14, 3231–3246, 2014.
Hoyle, C.R. et al., “Heterogeneous formation of polar stratospheric clouds – Part 1: Nucleation of nitric acid trihydrate (NAT)”, Atmos. Chem. Phys., 13, 9577–9595, 2013.
Murphy, D. M. et al., “In Situ Measurements of Organics, Meteoritic Material, Mercury, and Other Elements in Aerosols at 5 to 19 Kilometers, Science, VOL 282, 1664—1669,1998.
Murphy, D. M. et al.”Observations of the chemical composition of stratospheric aerosol particles” Q. J. R. Meteorol. Soc. 140: 1269–1278,,2014.
Pitts, M. C. “The 2009–2010 Arctic polar stratospheric cloud season: a CALIPSO perspective”, Atmos. Chem. Phys., 11, 2161–2177, 2011.
Voigt C. et al., “Nitric Acid Trihydrate (NAT) formation at low NAT supersaturation in Polar Stratospheric Clouds (PSCs)” Atmos. Chem. Phys., 5, 1371–1380, 2005.
Weigel R. et al. “Enhancements of the refractory submicron aerosol fraction in the Arctic polar vortex: feature or exception?” Atmos. Chem. Phys., 14, 12319–12342, 2014. |
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