Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere
We analyse middle atmospheric profiles of temperature, geopotential height, water vapour volume mixing ratio, and ozone volume mixing ratio above Bern (46.95 ∘ N, 7.44 ∘ E). These profiles were observed by the satellite experiment Aura/MLS and the ground-based microwave radiometers MIAWA...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-05-01
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| Series: | Atmosphere |
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| Online Access: | http://www.mdpi.com/2073-4433/9/5/171 |
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| author | Klemens Hocke Martin Lainer Leonie Bernet Niklaus Kämpfer |
| author_facet | Klemens Hocke Martin Lainer Leonie Bernet Niklaus Kämpfer |
| author_sort | Klemens Hocke |
| collection | DOAJ |
| description | We analyse middle atmospheric profiles of temperature, geopotential height, water vapour volume mixing ratio, and ozone volume mixing ratio above Bern (46.95 ∘ N, 7.44 ∘ E). These profiles were observed by the satellite experiment Aura/MLS and the ground-based microwave radiometers MIAWARA and GROMOS at Bern. The data series of Aura/MLS and GROMOS extend from the winter 2004/2005 to the winter 2017/2018 while the MIAWARA series starts in winter 2007/2008. Mesospheric inversion layers (MILs) above Bern, Switzerland are often present during the winter season, and the temperature peak of the MIL is located at an altitude of about 81 km in winter. The occurrence rate of the MIL during the winter season above Bern is about 42%. The MILs are possibly associated with planetary wave breaking processes in the mesospheric surf zone at mid-latitudes during winter. The study only evaluates daily averages in order to reduce tidal influences. Composite atmospheric profiles are computed for times when the MIL is present and for times when the MIL is absent. The difference of the composites indicates that middle and upper stratospheric ozone are reduced by up to 7% when the MIL is present while lower mesospheric water vapour is enhanced by up to 20% during the MIL occurrence. Using wind data of ECMWF operational analysis, we find that eastward and northward winds are decelerated by about 5–15 m/s in the lower mesosphere during the occurrence of an MIL. We also find that the occurrence of an MIL above Bern is not a regional process, but it depends on the movements and deformations of the polar mesospheric vortex. During an MIL, the location of Bern is outside of the lower mesospheric vortex. These new findings of atmospheric composition and circulation changes support the assumption that winter MILs at mid-latitudes are connected to planetary wave breaking in the middle atmosphere. |
| first_indexed | 2024-12-13T16:00:40Z |
| format | Article |
| id | doaj.art-e1ea0ef81b454db0b35fcf98feb98868 |
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| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-12-13T16:00:40Z |
| publishDate | 2018-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-e1ea0ef81b454db0b35fcf98feb988682022-12-21T23:39:10ZengMDPI AGAtmosphere2073-44332018-05-019517110.3390/atmos9050171atmos9050171Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle AtmosphereKlemens Hocke0Martin Lainer1Leonie Bernet2Niklaus Kämpfer3Institute of Applied Physics and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, SwitzerlandInstitute of Applied Physics and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, SwitzerlandInstitute of Applied Physics and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, SwitzerlandInstitute of Applied Physics and Oeschger Centre for Climate Change Research, University of Bern, 3012 Bern, SwitzerlandWe analyse middle atmospheric profiles of temperature, geopotential height, water vapour volume mixing ratio, and ozone volume mixing ratio above Bern (46.95 ∘ N, 7.44 ∘ E). These profiles were observed by the satellite experiment Aura/MLS and the ground-based microwave radiometers MIAWARA and GROMOS at Bern. The data series of Aura/MLS and GROMOS extend from the winter 2004/2005 to the winter 2017/2018 while the MIAWARA series starts in winter 2007/2008. Mesospheric inversion layers (MILs) above Bern, Switzerland are often present during the winter season, and the temperature peak of the MIL is located at an altitude of about 81 km in winter. The occurrence rate of the MIL during the winter season above Bern is about 42%. The MILs are possibly associated with planetary wave breaking processes in the mesospheric surf zone at mid-latitudes during winter. The study only evaluates daily averages in order to reduce tidal influences. Composite atmospheric profiles are computed for times when the MIL is present and for times when the MIL is absent. The difference of the composites indicates that middle and upper stratospheric ozone are reduced by up to 7% when the MIL is present while lower mesospheric water vapour is enhanced by up to 20% during the MIL occurrence. Using wind data of ECMWF operational analysis, we find that eastward and northward winds are decelerated by about 5–15 m/s in the lower mesosphere during the occurrence of an MIL. We also find that the occurrence of an MIL above Bern is not a regional process, but it depends on the movements and deformations of the polar mesospheric vortex. During an MIL, the location of Bern is outside of the lower mesospheric vortex. These new findings of atmospheric composition and circulation changes support the assumption that winter MILs at mid-latitudes are connected to planetary wave breaking in the middle atmosphere.http://www.mdpi.com/2073-4433/9/5/171mesospheric inversion layermiddle atmosphereozonewater vapourplanetary wavemicrowave radiometry |
| spellingShingle | Klemens Hocke Martin Lainer Leonie Bernet Niklaus Kämpfer Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere Atmosphere mesospheric inversion layer middle atmosphere ozone water vapour planetary wave microwave radiometry |
| title | Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere |
| title_full | Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere |
| title_fullStr | Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere |
| title_full_unstemmed | Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere |
| title_short | Mesospheric Inversion Layers at Mid-Latitudes and Coincident Changes of Ozone, Water Vapour and Horizontal Wind in the Middle Atmosphere |
| title_sort | mesospheric inversion layers at mid latitudes and coincident changes of ozone water vapour and horizontal wind in the middle atmosphere |
| topic | mesospheric inversion layer middle atmosphere ozone water vapour planetary wave microwave radiometry |
| url | http://www.mdpi.com/2073-4433/9/5/171 |
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