Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean
The Southern Ocean (in the region 60-180° E) south of the Indian Ocean, Australia, and the West Pacific is noted for the frequent occurrence and severity of its storms. These storms give rise to high-amplitude secondary microseisms from sources, including the deep ocean regions, and primary microsei...
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ftunivtasmania:oai:eprints.utas.edu.au:33330 2023-05-15T13:31:54+02:00 Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean Turner, RJ Gal, M Hemer, MA Reading, AM 2020 application/pdf https://eprints.utas.edu.au/33330/ https://eprints.utas.edu.au/33330/1/139131%20-%20Impacts%20of%20the%20cryosphere%20and%20atmosphere%20on%20observed%20microseisms%20generated%20in%20the%20Southern%20Ocean.pdf en eng Wiley-Blackwell Publishing Ltd https://eprints.utas.edu.au/33330/1/139131%20-%20Impacts%20of%20the%20cryosphere%20and%20atmosphere%20on%20observed%20microseisms%20generated%20in%20the%20Southern%20Ocean.pdf Turner, RJ orcid:0000-0002-4376-5455 , Gal, M orcid:0000-0001-6767-8017 , Hemer, MA and Reading, AM orcid:0000-0002-9316-7605 2020 , 'Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean' , Journal of Geophysical Research: Earth Surface, vol. 125, no. 2 , pp. 1-16 , doi:10.1029/2019JF005354 <http://dx.doi.org/10.1029/2019JF005354>. microseisms southern ocean sea ice southern annular mode (SAM) Article PeerReviewed 2020 ftunivtasmania https://doi.org/10.1029/2019JF005354 2021-10-04T22:17:50Z The Southern Ocean (in the region 60-180° E) south of the Indian Ocean, Australia, and the West Pacific is noted for the frequent occurrence and severity of its storms. These storms give rise to high-amplitude secondary microseisms from sources, including the deep ocean regions, and primary microseisms where the swells impinge on submarine topographic features. A better understanding of the varying microseism wavefield enables improvements to seismic imaging and development of proxy observables to complement sparse in situ wave observations and hindcast models of the global ocean wave climate. We analyze 12-26 years of seismic data from 11 seismic stations either on the East Antarctic coast or sited in the Indian Ocean, Australia, and New Zealand. The power spectral density of the seismic wavefield is calculated to explore how the time-changing microseism intensity varies with (i) sea ice coverage surrounding Antarctica and (ii) the Southern Annular Mode (SAM) climate index. Variations in sea ice extent are found to be the dominant control on the microseism intensity at Antarctic stations, which exhibit a seasonal pattern phase-shifted by 4-5 months compared to stations in other continents. Peaks in extremal intensity at East Antarctic stations occur in March-April, with the highest peaks for secondary microseisms occurring during negative SAM events. This relationship between microseism intensity and the SAM index is opposite to that observed on the Antarctic Peninsula. This work informs the complexity of microseism amplitudes in the Southern Hemisphere and assists ongoing interdisciplinary investigations of interannual variability and long-term trends. Article in Journal/Newspaper Antarc* Antarctic Antarctic Peninsula Antarctica Sea ice Southern Ocean The Cryosphere University of Tasmania: UTas ePrints Antarctic Southern Ocean The Antarctic Antarctic Peninsula Pacific Indian New Zealand Journal of Geophysical Research: Earth Surface 125 2 |
institution |
Open Polar |
collection |
University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
microseisms southern ocean sea ice southern annular mode (SAM) |
spellingShingle |
microseisms southern ocean sea ice southern annular mode (SAM) Turner, RJ Gal, M Hemer, MA Reading, AM Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
topic_facet |
microseisms southern ocean sea ice southern annular mode (SAM) |
description |
The Southern Ocean (in the region 60-180° E) south of the Indian Ocean, Australia, and the West Pacific is noted for the frequent occurrence and severity of its storms. These storms give rise to high-amplitude secondary microseisms from sources, including the deep ocean regions, and primary microseisms where the swells impinge on submarine topographic features. A better understanding of the varying microseism wavefield enables improvements to seismic imaging and development of proxy observables to complement sparse in situ wave observations and hindcast models of the global ocean wave climate. We analyze 12-26 years of seismic data from 11 seismic stations either on the East Antarctic coast or sited in the Indian Ocean, Australia, and New Zealand. The power spectral density of the seismic wavefield is calculated to explore how the time-changing microseism intensity varies with (i) sea ice coverage surrounding Antarctica and (ii) the Southern Annular Mode (SAM) climate index. Variations in sea ice extent are found to be the dominant control on the microseism intensity at Antarctic stations, which exhibit a seasonal pattern phase-shifted by 4-5 months compared to stations in other continents. Peaks in extremal intensity at East Antarctic stations occur in March-April, with the highest peaks for secondary microseisms occurring during negative SAM events. This relationship between microseism intensity and the SAM index is opposite to that observed on the Antarctic Peninsula. This work informs the complexity of microseism amplitudes in the Southern Hemisphere and assists ongoing interdisciplinary investigations of interannual variability and long-term trends. |
format |
Article in Journal/Newspaper |
author |
Turner, RJ Gal, M Hemer, MA Reading, AM |
author_facet |
Turner, RJ Gal, M Hemer, MA Reading, AM |
author_sort |
Turner, RJ |
title |
Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
title_short |
Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
title_full |
Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
title_fullStr |
Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
title_full_unstemmed |
Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean |
title_sort |
impacts of the cryosphere and atmosphere on observed microseisms generated in the southern ocean |
publisher |
Wiley-Blackwell Publishing Ltd |
publishDate |
2020 |
url |
https://eprints.utas.edu.au/33330/ https://eprints.utas.edu.au/33330/1/139131%20-%20Impacts%20of%20the%20cryosphere%20and%20atmosphere%20on%20observed%20microseisms%20generated%20in%20the%20Southern%20Ocean.pdf |
geographic |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Pacific Indian New Zealand |
geographic_facet |
Antarctic Southern Ocean The Antarctic Antarctic Peninsula Pacific Indian New Zealand |
genre |
Antarc* Antarctic Antarctic Peninsula Antarctica Sea ice Southern Ocean The Cryosphere |
genre_facet |
Antarc* Antarctic Antarctic Peninsula Antarctica Sea ice Southern Ocean The Cryosphere |
op_relation |
https://eprints.utas.edu.au/33330/1/139131%20-%20Impacts%20of%20the%20cryosphere%20and%20atmosphere%20on%20observed%20microseisms%20generated%20in%20the%20Southern%20Ocean.pdf Turner, RJ orcid:0000-0002-4376-5455 , Gal, M orcid:0000-0001-6767-8017 , Hemer, MA and Reading, AM orcid:0000-0002-9316-7605 2020 , 'Impacts of the cryosphere and atmosphere on observed microseisms generated in the Southern Ocean' , Journal of Geophysical Research: Earth Surface, vol. 125, no. 2 , pp. 1-16 , doi:10.1029/2019JF005354 <http://dx.doi.org/10.1029/2019JF005354>. |
op_doi |
https://doi.org/10.1029/2019JF005354 |
container_title |
Journal of Geophysical Research: Earth Surface |
container_volume |
125 |
container_issue |
2 |
_version_ |
1766022232273846272 |