Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar
We present an extensive data set of simultaneous temperature and wind measurements in the Arctic middle atmosphere. It consists of more than 300 h of Doppler Rayleigh lidar observations obtained during three January seasons (2012, 2014, and 2015) and covers the altitude range from 30 km up to ab...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-11-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/13345/2017/acp-17-13345-2017.pdf |
| _version_ | 1819150206877302784 |
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| author | J. Hildebrand G. Baumgarten J. Fiedler F.-J. Lübken |
| author_facet | J. Hildebrand G. Baumgarten J. Fiedler F.-J. Lübken |
| author_sort | J. Hildebrand |
| collection | DOAJ |
| description | We present an extensive data set of simultaneous temperature and
wind measurements in the Arctic middle atmosphere. It consists of
more than 300 h of Doppler Rayleigh lidar observations obtained
during three January seasons (2012, 2014, and 2015) and covers the
altitude range from 30 km up to about 85 km. The data set
reveals large year-to-year variations in monthly mean temperatures
and winds, which in 2012 are affected by a sudden stratospheric
warming. The temporal evolution of winds and temperatures after
that warming are studied over a period of 2 weeks, showing an
elevated stratopause and the reformation of the polar vortex.
The monthly mean temperatures and winds are compared to data
extracted from the Integrated Forecast System of the European Centre
for Medium-Range Weather Forecasts (ECMWF) and the Horizontal Wind
Model (HWM07). Lidar and ECMWF data show good agreement of mean
zonal and meridional winds below ≈ 55 km altitude, but we
also find mean temperature, zonal wind, and meridional wind
differences of up to 20 K, 20 m s<sup>−1</sup>, and
5 m s<sup>−1</sup>, respectively. Differences between lidar
observations and HWM07 data are up to 30 m s<sup>−1</sup>.
From the fluctuations of temperatures and winds within single nights
we extract the potential and kinetic gravity wave energy
density (GWED) per unit mass. It shows that the kinetic GWED is
typically 5 to 10 times larger than the potential GWED, the
total GWED increases with altitude with a scale height of ≈ 16 km. Since temporal fluctuations of winds and temperatures are
underestimated in ECMWF, the total GWED is underestimated as well by
a factor of 3–10 above 50 km altitude.
Similarly, we estimate the energy density per unit mass for
large-scale waves (LWED) from the fluctuations of nightly mean
temperatures and winds. The total LWED is roughly constant with
altitude. The ratio of kinetic to potential LWED varies with
altitude over 2 orders of magnitude. LWEDs from ECMWF data show
results similar to the lidar data.
From the comparison of GWED and LWED, it follows that large-scale
waves carry about 2 to 5 times more energy than gravity waves. |
| first_indexed | 2024-12-22T14:13:49Z |
| format | Article |
| id | doaj.art-587ce3f15ebf46c4a20a4b78b7eb4701 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-12-22T14:13:49Z |
| publishDate | 2017-11-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-587ce3f15ebf46c4a20a4b78b7eb47012022-12-21T18:23:10ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-11-0117133451335910.5194/acp-17-13345-2017Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidarJ. Hildebrand0G. Baumgarten1J. Fiedler2F.-J. Lübken3Leibniz-Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, GermanyLeibniz-Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, GermanyLeibniz-Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, GermanyLeibniz-Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, GermanyWe present an extensive data set of simultaneous temperature and wind measurements in the Arctic middle atmosphere. It consists of more than 300 h of Doppler Rayleigh lidar observations obtained during three January seasons (2012, 2014, and 2015) and covers the altitude range from 30 km up to about 85 km. The data set reveals large year-to-year variations in monthly mean temperatures and winds, which in 2012 are affected by a sudden stratospheric warming. The temporal evolution of winds and temperatures after that warming are studied over a period of 2 weeks, showing an elevated stratopause and the reformation of the polar vortex. The monthly mean temperatures and winds are compared to data extracted from the Integrated Forecast System of the European Centre for Medium-Range Weather Forecasts (ECMWF) and the Horizontal Wind Model (HWM07). Lidar and ECMWF data show good agreement of mean zonal and meridional winds below ≈ 55 km altitude, but we also find mean temperature, zonal wind, and meridional wind differences of up to 20 K, 20 m s<sup>−1</sup>, and 5 m s<sup>−1</sup>, respectively. Differences between lidar observations and HWM07 data are up to 30 m s<sup>−1</sup>. From the fluctuations of temperatures and winds within single nights we extract the potential and kinetic gravity wave energy density (GWED) per unit mass. It shows that the kinetic GWED is typically 5 to 10 times larger than the potential GWED, the total GWED increases with altitude with a scale height of ≈ 16 km. Since temporal fluctuations of winds and temperatures are underestimated in ECMWF, the total GWED is underestimated as well by a factor of 3–10 above 50 km altitude. Similarly, we estimate the energy density per unit mass for large-scale waves (LWED) from the fluctuations of nightly mean temperatures and winds. The total LWED is roughly constant with altitude. The ratio of kinetic to potential LWED varies with altitude over 2 orders of magnitude. LWEDs from ECMWF data show results similar to the lidar data. From the comparison of GWED and LWED, it follows that large-scale waves carry about 2 to 5 times more energy than gravity waves.https://www.atmos-chem-phys.net/17/13345/2017/acp-17-13345-2017.pdf |
| spellingShingle | J. Hildebrand G. Baumgarten J. Fiedler F.-J. Lübken Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar Atmospheric Chemistry and Physics |
| title | Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar |
| title_full | Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar |
| title_fullStr | Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar |
| title_full_unstemmed | Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar |
| title_short | Winds and temperatures of the Arctic middle atmosphere during January measured by Doppler lidar |
| title_sort | winds and temperatures of the arctic middle atmosphere during january measured by doppler lidar |
| url | https://www.atmos-chem-phys.net/17/13345/2017/acp-17-13345-2017.pdf |
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