Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere
Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (∼ 54◦ N) and northern Norway (∼ 69◦ N). This work investigates the mesospheric mean zonal wind and the zonal mean geostrophic zonal wind from the Microwa...
Published in: | Annales Geophysicae |
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Online Access: | https://elib.dlr.de/185306/ https://elib.dlr.de/185306/1/angeo-40-23-2022.pdf https://angeo.copernicus.org/articles/40/23/2022/ |
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ftdlr:oai:elib.dlr.de:185306 2023-05-15T17:43:38+02:00 Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere Jaen, Juliana Renkwitz, Toralf Chau, Jorge L. He, Maosheng Hoffmann, Peter Yamazaki, Yosuke Jacobi, Christoph Tsutsumi, Masaki Matthias, Vivien Hall, Chris 2022-01-20 application/pdf https://elib.dlr.de/185306/ https://elib.dlr.de/185306/1/angeo-40-23-2022.pdf https://angeo.copernicus.org/articles/40/23/2022/ en eng Copernicus Publications https://elib.dlr.de/185306/1/angeo-40-23-2022.pdf Jaen, Juliana und Renkwitz, Toralf und Chau, Jorge L. und He, Maosheng und Hoffmann, Peter und Yamazaki, Yosuke und Jacobi, Christoph und Tsutsumi, Masaki und Matthias, Vivien und Hall, Chris (2022) Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere. Annales Geophysicae, 40 (1), Seiten 23-35. Copernicus Publications. doi:10.5194/angeo-40-23-2022 <https://doi.org/10.5194/angeo-40-23-2022>. ISSN 0992-7689. Solar-Terrestrische Kopplungsprozesse Zeitschriftenbeitrag PeerReviewed 2022 ftdlr https://doi.org/10.5194/angeo-40-23-2022 2022-02-28T00:10:33Z Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (∼ 54◦ N) and northern Norway (∼ 69◦ N). This work investigates the mesospheric mean zonal wind and the zonal mean geostrophic zonal wind from the Microwave Limb Sounder (MLS) over these two regions between 2004 and 2020. Our study focuses on the summer when strong planetary waves are absent and the stratospheric and tropospheric conditions are relatively stable. We establish two definitions of the summer length according to the zonal wind reversals: (1) the mesosphere and lower-thermosphere summer length (MLTSL) using SMR and PRR winds and (2) the mesosphere summer length (M-SL) using the PRR and MLS. Under both definitions, the summer begins around April and ends around middle September. The largest year-to-year variability is found in the summer beginning in both definitions, particularly at high latitudes, possibly due to the influence of the polar vortex. At high latitudes, the year 2004 has a longer summer length compared to the mean value for MLT-SL as well as 2012 for both definitions. The M-SL exhibits an increasing trend over the years, while MLT-SL does not have a well-defined trend. We explore a possible influence of solar activity as well as large-scale atmospheric influences (e.g., quasi-biennial oscillation (QBO), El Niño–Southern Oscillation (ENSO), major sudden stratospheric warming events). We complement our work with an extended time series of 31 years at middle latitudes using only PRR winds. In this case, the summer length shows a breakpoint, suggesting a non-uniform trend, and periods similar to those known for ENSO and QBO. Other Non-Article Part of Journal/Newspaper Northern Norway German Aerospace Center: elib - DLR electronic library Norway Annales Geophysicae 40 1 23 35 |
institution |
Open Polar |
collection |
German Aerospace Center: elib - DLR electronic library |
op_collection_id |
ftdlr |
language |
English |
topic |
Solar-Terrestrische Kopplungsprozesse |
spellingShingle |
Solar-Terrestrische Kopplungsprozesse Jaen, Juliana Renkwitz, Toralf Chau, Jorge L. He, Maosheng Hoffmann, Peter Yamazaki, Yosuke Jacobi, Christoph Tsutsumi, Masaki Matthias, Vivien Hall, Chris Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
topic_facet |
Solar-Terrestrische Kopplungsprozesse |
description |
Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (∼ 54◦ N) and northern Norway (∼ 69◦ N). This work investigates the mesospheric mean zonal wind and the zonal mean geostrophic zonal wind from the Microwave Limb Sounder (MLS) over these two regions between 2004 and 2020. Our study focuses on the summer when strong planetary waves are absent and the stratospheric and tropospheric conditions are relatively stable. We establish two definitions of the summer length according to the zonal wind reversals: (1) the mesosphere and lower-thermosphere summer length (MLTSL) using SMR and PRR winds and (2) the mesosphere summer length (M-SL) using the PRR and MLS. Under both definitions, the summer begins around April and ends around middle September. The largest year-to-year variability is found in the summer beginning in both definitions, particularly at high latitudes, possibly due to the influence of the polar vortex. At high latitudes, the year 2004 has a longer summer length compared to the mean value for MLT-SL as well as 2012 for both definitions. The M-SL exhibits an increasing trend over the years, while MLT-SL does not have a well-defined trend. We explore a possible influence of solar activity as well as large-scale atmospheric influences (e.g., quasi-biennial oscillation (QBO), El Niño–Southern Oscillation (ENSO), major sudden stratospheric warming events). We complement our work with an extended time series of 31 years at middle latitudes using only PRR winds. In this case, the summer length shows a breakpoint, suggesting a non-uniform trend, and periods similar to those known for ENSO and QBO. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
Jaen, Juliana Renkwitz, Toralf Chau, Jorge L. He, Maosheng Hoffmann, Peter Yamazaki, Yosuke Jacobi, Christoph Tsutsumi, Masaki Matthias, Vivien Hall, Chris |
author_facet |
Jaen, Juliana Renkwitz, Toralf Chau, Jorge L. He, Maosheng Hoffmann, Peter Yamazaki, Yosuke Jacobi, Christoph Tsutsumi, Masaki Matthias, Vivien Hall, Chris |
author_sort |
Jaen, Juliana |
title |
Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
title_short |
Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
title_full |
Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
title_fullStr |
Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
title_full_unstemmed |
Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere |
title_sort |
long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the northern hemisphere |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://elib.dlr.de/185306/ https://elib.dlr.de/185306/1/angeo-40-23-2022.pdf https://angeo.copernicus.org/articles/40/23/2022/ |
geographic |
Norway |
geographic_facet |
Norway |
genre |
Northern Norway |
genre_facet |
Northern Norway |
op_relation |
https://elib.dlr.de/185306/1/angeo-40-23-2022.pdf Jaen, Juliana und Renkwitz, Toralf und Chau, Jorge L. und He, Maosheng und Hoffmann, Peter und Yamazaki, Yosuke und Jacobi, Christoph und Tsutsumi, Masaki und Matthias, Vivien und Hall, Chris (2022) Long-term studies of mesosphere and lower-thermosphere summer length definitions based on mean zonal wind features observed for more than one solar cycle at middle and high latitudes in the Northern Hemisphere. Annales Geophysicae, 40 (1), Seiten 23-35. Copernicus Publications. doi:10.5194/angeo-40-23-2022 <https://doi.org/10.5194/angeo-40-23-2022>. ISSN 0992-7689. |
op_doi |
https://doi.org/10.5194/angeo-40-23-2022 |
container_title |
Annales Geophysicae |
container_volume |
40 |
container_issue |
1 |
container_start_page |
23 |
op_container_end_page |
35 |
_version_ |
1766145762637381632 |