Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves
Effects of mid-latitude Sea Surface Temperature (SST) fronts on the middle atmosphere were investigated by using the high-top MIROC AGCM. This model has horizontal and vertical resolutions of ~120km and 550 m, respectively, with model top of ~95 km. Non-orographic gravity wave parameterizations were...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5020765 2023-07-23T04:21:29+02:00 Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves Kawatani, Y. Nakamura, H. Sato, K. Watanabe, S. 2023-07-11 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020765 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-3780 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020765 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-3780 2023-07-02T23:40:07Z Effects of mid-latitude Sea Surface Temperature (SST) fronts on the middle atmosphere were investigated by using the high-top MIROC AGCM. This model has horizontal and vertical resolutions of ~120km and 550 m, respectively, with model top of ~95 km. Non-orographic gravity wave parameterizations were not included. We have conducted two idealized experiments. One used the SST with realistic meridional gradients (control run), and the other did the SST with smoothing meridional gradients of mid-latitude SST front (no SST front run; NF run), similar to the previous study (e.g., Nakamura et al. 2008). Previous numerical experiments showed that mid-latitude SST fronts affect precipitation, heat fluxes, and baroclinic wave activities in the troposphere. Our model experiments further showed that more gravity waves were generated around baroclinic waves in the control run than the NF run, which propagate into the stratosphere and mesosphere. Wave momentum fluxes associated with these gravity waves are larger from the upper troposphere to ~0.03 hPa, resulting in larger westward forcing in the control run. Amplitudes of gravity waves in the NF run were smaller than those in the control run, and these waves tend to be dissipated at higher altitudes. Shapes of the zonal mean zonal winds including polar night jets are more realistic in the control run, indicating the SST fronts have impact on not only the troposphere but also on the middle atmosphere. Conference Object polar night GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
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Open Polar |
collection |
GFZpublic (German Research Centre for Geosciences, Helmholtz-Zentrum Potsdam) |
op_collection_id |
ftgfzpotsdam |
language |
English |
description |
Effects of mid-latitude Sea Surface Temperature (SST) fronts on the middle atmosphere were investigated by using the high-top MIROC AGCM. This model has horizontal and vertical resolutions of ~120km and 550 m, respectively, with model top of ~95 km. Non-orographic gravity wave parameterizations were not included. We have conducted two idealized experiments. One used the SST with realistic meridional gradients (control run), and the other did the SST with smoothing meridional gradients of mid-latitude SST front (no SST front run; NF run), similar to the previous study (e.g., Nakamura et al. 2008). Previous numerical experiments showed that mid-latitude SST fronts affect precipitation, heat fluxes, and baroclinic wave activities in the troposphere. Our model experiments further showed that more gravity waves were generated around baroclinic waves in the control run than the NF run, which propagate into the stratosphere and mesosphere. Wave momentum fluxes associated with these gravity waves are larger from the upper troposphere to ~0.03 hPa, resulting in larger westward forcing in the control run. Amplitudes of gravity waves in the NF run were smaller than those in the control run, and these waves tend to be dissipated at higher altitudes. Shapes of the zonal mean zonal winds including polar night jets are more realistic in the control run, indicating the SST fronts have impact on not only the troposphere but also on the middle atmosphere. |
format |
Conference Object |
author |
Kawatani, Y. Nakamura, H. Sato, K. Watanabe, S. |
spellingShingle |
Kawatani, Y. Nakamura, H. Sato, K. Watanabe, S. Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
author_facet |
Kawatani, Y. Nakamura, H. Sato, K. Watanabe, S. |
author_sort |
Kawatani, Y. |
title |
Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
title_short |
Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
title_full |
Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
title_fullStr |
Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
title_full_unstemmed |
Effects of mid-latitude SST fronts on the middle atmosphere through upward propagating atmospheric waves |
title_sort |
effects of mid-latitude sst fronts on the middle atmosphere through upward propagating atmospheric waves |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020765 |
genre |
polar night |
genre_facet |
polar night |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-3780 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020765 |
op_doi |
https://doi.org/10.57757/IUGG23-3780 |
_version_ |
1772187136272891904 |