Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016
The Arctic winter 2015–2016 was characterized by exceptionally low stratospheric temperatures, favouring the formation of polar stratospheric clouds (PSCs) from mid-December until the end of February down to low stratospheric altitudes. Observations by GLORIA (Gimballed Limb Observer for Radiance Im...
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Online Access: | https://doi.org/10.5194/acp-19-13681-2019 https://www.atmos-chem-phys.net/19/13681/2019/ |
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ftcopernicus:oai:publications.copernicus.org:acp74448 2023-05-15T14:59:05+02:00 Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 Braun, Marleen Grooß, Jens-Uwe Woiwode, Wolfgang Johansson, Sören Höpfner, Michael Friedl-Vallon, Felix Oelhaf, Hermann Preusse, Peter Ungermann, Jörn Sinnhuber, Björn-Martin Ziereis, Helmut Braesicke, Peter 2019-11-11 info:eu-repo/semantics/application/pdf https://doi.org/10.5194/acp-19-13681-2019 https://www.atmos-chem-phys.net/19/13681/2019/ eng eng info:eu-repo/grantAgreement/EC/FP7/603557 doi:10.5194/acp-19-13681-2019 https://www.atmos-chem-phys.net/19/13681/2019/ info:eu-repo/semantics/openAccess eISSN: 1680-7324 info:eu-repo/semantics/Text 2019 ftcopernicus https://doi.org/10.5194/acp-19-13681-2019 2019-12-24T09:48:14Z The Arctic winter 2015–2016 was characterized by exceptionally low stratospheric temperatures, favouring the formation of polar stratospheric clouds (PSCs) from mid-December until the end of February down to low stratospheric altitudes. Observations by GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) on HALO (High Altitude and LOng range research aircraft) during the PGS (POLSTRACC–GW-LCYCLE II–SALSA) campaign from December 2015 to March 2016 allow the investigation of the influence of denitrification on the lowermost stratosphere (LMS) with a high spatial resolution. Two-dimensional vertical cross sections of nitric acid ( HNO 3 ) along the flight track and tracer–tracer correlations derived from the GLORIA observations document detailed pictures of wide-spread nitrification of the Arctic LMS during the course of an entire winter. GLORIA observations show large-scale structures and local fine structures with enhanced absolute HNO 3 volume mixing ratios reaching up to 11 ppbv at altitudes of 13 km in January and nitrified filaments persisting until the middle of March. Narrow coherent structures tilted with altitude of enhanced HNO 3 , observed in mid-January, are interpreted as regions recently nitrified by sublimating HNO 3 -containing particles. Overall, extensive nitrification of the LMS between 5.0 and 7.0 ppbv at potential temperature levels between 350 and 380 K is estimated. The GLORIA observations are compared with CLaMS (Chemical Lagrangian Model of the Stratosphere) simulations. The fundamental structures observed by GLORIA are well reproduced, but differences in the fine structures are diagnosed. Further, CLaMS predominantly underestimates the spatial extent of HNO 3 maxima derived from the GLORIA observations as well as the overall nitrification of the LMS. Sensitivity simulations with CLaMS including (i) enhanced sedimentation rates in case of ice supersaturation (to resemble ice nucleation on nitric acid trihydrate (NAT)), (ii) a global temperature offset, (iii) modified growth rates (to resemble aspherical particles with larger surfaces) and (iv) temperature fluctuations (to resemble the impact of small-scale mountain waves) slightly improved the agreement with the GLORIA observations of individual flights. However, no parameter could be isolated which resulted in a general improvement for all flights. Still, the sensitivity simulations suggest that details of particle microphysics play a significant role for simulated LMS nitrification in January, while air subsidence, transport and mixing become increasingly important for the simulated HNO 3 distributions towards the end of the winter. Other/Unknown Material Arctic Copernicus Publications: E-Journals Arctic Atmospheric Chemistry and Physics 19 21 13681 13699 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
The Arctic winter 2015–2016 was characterized by exceptionally low stratospheric temperatures, favouring the formation of polar stratospheric clouds (PSCs) from mid-December until the end of February down to low stratospheric altitudes. Observations by GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) on HALO (High Altitude and LOng range research aircraft) during the PGS (POLSTRACC–GW-LCYCLE II–SALSA) campaign from December 2015 to March 2016 allow the investigation of the influence of denitrification on the lowermost stratosphere (LMS) with a high spatial resolution. Two-dimensional vertical cross sections of nitric acid ( HNO 3 ) along the flight track and tracer–tracer correlations derived from the GLORIA observations document detailed pictures of wide-spread nitrification of the Arctic LMS during the course of an entire winter. GLORIA observations show large-scale structures and local fine structures with enhanced absolute HNO 3 volume mixing ratios reaching up to 11 ppbv at altitudes of 13 km in January and nitrified filaments persisting until the middle of March. Narrow coherent structures tilted with altitude of enhanced HNO 3 , observed in mid-January, are interpreted as regions recently nitrified by sublimating HNO 3 -containing particles. Overall, extensive nitrification of the LMS between 5.0 and 7.0 ppbv at potential temperature levels between 350 and 380 K is estimated. The GLORIA observations are compared with CLaMS (Chemical Lagrangian Model of the Stratosphere) simulations. The fundamental structures observed by GLORIA are well reproduced, but differences in the fine structures are diagnosed. Further, CLaMS predominantly underestimates the spatial extent of HNO 3 maxima derived from the GLORIA observations as well as the overall nitrification of the LMS. Sensitivity simulations with CLaMS including (i) enhanced sedimentation rates in case of ice supersaturation (to resemble ice nucleation on nitric acid trihydrate (NAT)), (ii) a global temperature offset, (iii) modified growth rates (to resemble aspherical particles with larger surfaces) and (iv) temperature fluctuations (to resemble the impact of small-scale mountain waves) slightly improved the agreement with the GLORIA observations of individual flights. However, no parameter could be isolated which resulted in a general improvement for all flights. Still, the sensitivity simulations suggest that details of particle microphysics play a significant role for simulated LMS nitrification in January, while air subsidence, transport and mixing become increasingly important for the simulated HNO 3 distributions towards the end of the winter. |
format |
Other/Unknown Material |
author |
Braun, Marleen Grooß, Jens-Uwe Woiwode, Wolfgang Johansson, Sören Höpfner, Michael Friedl-Vallon, Felix Oelhaf, Hermann Preusse, Peter Ungermann, Jörn Sinnhuber, Björn-Martin Ziereis, Helmut Braesicke, Peter |
spellingShingle |
Braun, Marleen Grooß, Jens-Uwe Woiwode, Wolfgang Johansson, Sören Höpfner, Michael Friedl-Vallon, Felix Oelhaf, Hermann Preusse, Peter Ungermann, Jörn Sinnhuber, Björn-Martin Ziereis, Helmut Braesicke, Peter Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
author_facet |
Braun, Marleen Grooß, Jens-Uwe Woiwode, Wolfgang Johansson, Sören Höpfner, Michael Friedl-Vallon, Felix Oelhaf, Hermann Preusse, Peter Ungermann, Jörn Sinnhuber, Björn-Martin Ziereis, Helmut Braesicke, Peter |
author_sort |
Braun, Marleen |
title |
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
title_short |
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
title_full |
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
title_fullStr |
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
title_full_unstemmed |
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016 |
title_sort |
nitrification of the lowermost stratosphere during the exceptionally cold arctic winter 2015–2016 |
publishDate |
2019 |
url |
https://doi.org/10.5194/acp-19-13681-2019 https://www.atmos-chem-phys.net/19/13681/2019/ |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
eISSN: 1680-7324 |
op_relation |
info:eu-repo/grantAgreement/EC/FP7/603557 doi:10.5194/acp-19-13681-2019 https://www.atmos-chem-phys.net/19/13681/2019/ |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/acp-19-13681-2019 |
container_title |
Atmospheric Chemistry and Physics |
container_volume |
19 |
container_issue |
21 |
container_start_page |
13681 |
op_container_end_page |
13699 |
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1766331217934811136 |