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 (g1/4g54g gN) and northern Norway (g1/4g69g gN). This work investigates the mesospheric mean zonal wind and the zonal mean geostrophic zonal wind from the...

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Main Authors: Jaen, Juliana, Renkwitz, Toralf, Chau, Jorge L., He, Maosheng, Hoffmann, Peter, Yamazaki, Yosuke, Jacobi, Christoph, Tsutsumi, Masaki, Matthias, Vivien, Hall, Chris
Format: Article in Journal/Newspaper
Language:English
Published: Katlenburg, Lindau : Copernicus 2022
Subjects:
550
Online Access:https://oa.tib.eu/renate/handle/123456789/11837
https://doi.org/10.34657/10870
id ftleibnizopen:oai:oai.leibnizopen.de:59JEfYoBNQPDO7WIAXW_
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spelling ftleibnizopen:oai:oai.leibnizopen.de:59JEfYoBNQPDO7WIAXW_ 2023-10-09T21:54:28+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 application/pdf https://oa.tib.eu/renate/handle/123456789/11837 https://doi.org/10.34657/10870 eng eng Katlenburg, Lindau : Copernicus CC BY 4.0 Unported https://creativecommons.org/licenses/by/4.0 Annales geophysicae 40 (2022), Nr. 1 Germany atmospheric dynamics El Nino-Southern Oscillation mesosphere seasonal variation 550 article Text 2022 ftleibnizopen https://doi.org/10.34657/10870 2023-09-10T23:17:53Z Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (g1/4g54g gN) and northern Norway (g1/4g69g gN). 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 (MLT-SL) 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. Leibniz_Fonds publishedVersion Article in Journal/Newspaper Northern Norway LeibnizOpen (The Leibniz Association) Norway
institution Open Polar
collection LeibnizOpen (The Leibniz Association)
op_collection_id ftleibnizopen
language English
topic Germany
atmospheric dynamics
El Nino-Southern Oscillation
mesosphere
seasonal variation
550
spellingShingle Germany
atmospheric dynamics
El Nino-Southern Oscillation
mesosphere
seasonal variation
550
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 Germany
atmospheric dynamics
El Nino-Southern Oscillation
mesosphere
seasonal variation
550
description Specular meteor radars (SMRs) and partial reflection radars (PRRs) have been observing mesospheric winds for more than a solar cycle over Germany (g1/4g54g gN) and northern Norway (g1/4g69g gN). 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 (MLT-SL) 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. Leibniz_Fonds publishedVersion
format Article in 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 Katlenburg, Lindau : Copernicus
publishDate 2022
url https://oa.tib.eu/renate/handle/123456789/11837
https://doi.org/10.34657/10870
geographic Norway
geographic_facet Norway
genre Northern Norway
genre_facet Northern Norway
op_source Annales geophysicae 40 (2022), Nr. 1
op_rights CC BY 4.0 Unported
https://creativecommons.org/licenses/by/4.0
op_doi https://doi.org/10.34657/10870
_version_ 1779318036418789376