Impact of geomagnetic excursions on atmospheric chemistry and dynamics
Geomagnetic excursions, i.e. short periods in time with much weaker geomagnetic fields and substantial changes in the position of the geomagnetic pole, occurred repeatedly in the Earth's history, e.g. the Laschamp event about 41 kyr ago. Although the next such excursion is certain to come, litt...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus
2014
|
Subjects: | |
Online Access: | https://hdl.handle.net/20.500.11850/87120 https://doi.org/10.3929/ethz-b-000087120 |
id |
ftethz:oai:www.research-collection.ethz.ch:20.500.11850/87120 |
---|---|
record_format |
openpolar |
spelling |
ftethz:oai:www.research-collection.ethz.ch:20.500.11850/87120 2023-05-15T13:53:55+02:00 Impact of geomagnetic excursions on atmospheric chemistry and dynamics Suter, I. Zech, Roland Anet, J.G. Peter, Thomas 2014 application/application/pdf https://hdl.handle.net/20.500.11850/87120 https://doi.org/10.3929/ethz-b-000087120 en eng Copernicus info:eu-repo/semantics/altIdentifier/doi/10.5194/cp-10-1183-2014 info:eu-repo/semantics/altIdentifier/wos/000338761600016 info:eu-repo/grantAgreement/SNF/Sinergia/130642 http://hdl.handle.net/20.500.11850/87120 doi:10.3929/ethz-b-000087120 info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 Unported CC-BY Climate of the Past, 10 (3) info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion 2014 ftethz https://doi.org/20.500.11850/87120 https://doi.org/10.3929/ethz-b-000087120 https://doi.org/10.5194/cp-10-1183-2014 2023-02-13T00:48:06Z Geomagnetic excursions, i.e. short periods in time with much weaker geomagnetic fields and substantial changes in the position of the geomagnetic pole, occurred repeatedly in the Earth's history, e.g. the Laschamp event about 41 kyr ago. Although the next such excursion is certain to come, little is known about the timing and possible consequences for the state of the atmosphere and the ecosystems. Here we use the global chemistry climate model SOCOL-MPIOM to simulate the effects of geomagnetic excursions on atmospheric ionization, chemistry and dynamics. Our simulations show significantly increased concentrations of nitrogen oxides (NOx) in the entire stratosphere, especially over Antarctica (+15%), due to enhanced ionization by galactic cosmic rays. Hydrogen oxides (HOx) are also produced in greater amounts (up to +40%) in the tropical and subtropical lower stratosphere, while their destruction by reactions with enhanced NOx prevails over the poles and in high altitudes (by −5%). Stratospheric ozone concentrations decrease globally above 20 km by 1–2% and at the northern hemispheric tropopause by up to 5% owing to the accelerated NOx-induced destruction. A 5% increase is found in the southern lower stratosphere and troposphere. In response to these changes in ozone and the concomitant changes in atmospheric heating rates, the Arctic vortex intensifies in boreal winter, while the Antarctic vortex weakens in austral winter and spring. Surface wind anomalies show significant intensification of the southern westerlies at their poleward edge during austral winter and a pronounced northward shift in spring. Major impacts on the global climate seem unlikely. ISSN:1814-9324 ISSN:1814-9332 Article in Journal/Newspaper Antarc* Antarctic Antarctica Arctic Geomagnetic Pole ETH Zürich Research Collection Antarctic Arctic Austral The Antarctic |
institution |
Open Polar |
collection |
ETH Zürich Research Collection |
op_collection_id |
ftethz |
language |
English |
description |
Geomagnetic excursions, i.e. short periods in time with much weaker geomagnetic fields and substantial changes in the position of the geomagnetic pole, occurred repeatedly in the Earth's history, e.g. the Laschamp event about 41 kyr ago. Although the next such excursion is certain to come, little is known about the timing and possible consequences for the state of the atmosphere and the ecosystems. Here we use the global chemistry climate model SOCOL-MPIOM to simulate the effects of geomagnetic excursions on atmospheric ionization, chemistry and dynamics. Our simulations show significantly increased concentrations of nitrogen oxides (NOx) in the entire stratosphere, especially over Antarctica (+15%), due to enhanced ionization by galactic cosmic rays. Hydrogen oxides (HOx) are also produced in greater amounts (up to +40%) in the tropical and subtropical lower stratosphere, while their destruction by reactions with enhanced NOx prevails over the poles and in high altitudes (by −5%). Stratospheric ozone concentrations decrease globally above 20 km by 1–2% and at the northern hemispheric tropopause by up to 5% owing to the accelerated NOx-induced destruction. A 5% increase is found in the southern lower stratosphere and troposphere. In response to these changes in ozone and the concomitant changes in atmospheric heating rates, the Arctic vortex intensifies in boreal winter, while the Antarctic vortex weakens in austral winter and spring. Surface wind anomalies show significant intensification of the southern westerlies at their poleward edge during austral winter and a pronounced northward shift in spring. Major impacts on the global climate seem unlikely. ISSN:1814-9324 ISSN:1814-9332 |
format |
Article in Journal/Newspaper |
author |
Suter, I. Zech, Roland Anet, J.G. Peter, Thomas |
spellingShingle |
Suter, I. Zech, Roland Anet, J.G. Peter, Thomas Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
author_facet |
Suter, I. Zech, Roland Anet, J.G. Peter, Thomas |
author_sort |
Suter, I. |
title |
Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
title_short |
Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
title_full |
Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
title_fullStr |
Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
title_full_unstemmed |
Impact of geomagnetic excursions on atmospheric chemistry and dynamics |
title_sort |
impact of geomagnetic excursions on atmospheric chemistry and dynamics |
publisher |
Copernicus |
publishDate |
2014 |
url |
https://hdl.handle.net/20.500.11850/87120 https://doi.org/10.3929/ethz-b-000087120 |
geographic |
Antarctic Arctic Austral The Antarctic |
geographic_facet |
Antarctic Arctic Austral The Antarctic |
genre |
Antarc* Antarctic Antarctica Arctic Geomagnetic Pole |
genre_facet |
Antarc* Antarctic Antarctica Arctic Geomagnetic Pole |
op_source |
Climate of the Past, 10 (3) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.5194/cp-10-1183-2014 info:eu-repo/semantics/altIdentifier/wos/000338761600016 info:eu-repo/grantAgreement/SNF/Sinergia/130642 http://hdl.handle.net/20.500.11850/87120 doi:10.3929/ethz-b-000087120 |
op_rights |
info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/3.0/ Creative Commons Attribution 3.0 Unported |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/20.500.11850/87120 https://doi.org/10.3929/ethz-b-000087120 https://doi.org/10.5194/cp-10-1183-2014 |
_version_ |
1766259397061771264 |