The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region
The Indian Ocean Dipole (IOD) is a major source of seasonal climate variability. This dipole has strong impacts on the Indian Ocean region and through teleconnections can influence the seasonal climate of remote regions. The strong IOD of 2019/2020 influenced the state and predictability of the Nort...
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ftgfzpotsdam:oai:gfzpublic.gfz-potsdam.de:item_5016002 2023-10-29T02:38:19+01:00 The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region Hempel, T. Weisheimer, A. Palmer, T. 2023 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016002 eng eng info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0442 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016002 XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) info:eu-repo/semantics/conferenceObject 2023 ftgfzpotsdam https://doi.org/10.57757/IUGG23-0442 2023-10-01T23:43:19Z The Indian Ocean Dipole (IOD) is a major source of seasonal climate variability. This dipole has strong impacts on the Indian Ocean region and through teleconnections can influence the seasonal climate of remote regions. The strong IOD of 2019/2020 influenced the state and predictability of the Northern Hemisphere extratropics. Thus, a good understanding of the mechanism of this teleconnection is desirable. In this contribution we investigate the special teleconnection of the winter 2019/2020. In model experiments with the OpenIFS from ECMWF we show that the NAO in the winter 2019/2020 is influenced by the IOD. We use hindcast ensembles of the DJF season 2019/2020 to analyse this teleconnection. In model experiments, the Sea Surface Temperature (SST) boundary conditions are perturbed. With these experiments we identify the relative importance of individual ocean regions to the state of the NAO in the winter of 2019/2020. We contrast the experiments to the operational ECMWF System5 forecast and ERA5. Experiments with the 2019/2020 SSTs in the Indian Ocean (with other boundary conditions set to climatology) reproduce many of the observed atmospheric 2019/2020 features. In contrast, experiments with SSTs in the Pacific show very different patterns. We identify eddy-mean-flow interactions as a mechanism that connects and transports information from the Indian Ocean to the North Atlantic. With Hoskins E-Vectors we show that anomalous eddy activity during IOD events impacts the position and strength of the Northern Hemisphere extratropical jet. This interaction provides a teleconnection mechanism in addition to the Rossby-wavetrain discussed in other studies. Conference Object North Atlantic 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 |
The Indian Ocean Dipole (IOD) is a major source of seasonal climate variability. This dipole has strong impacts on the Indian Ocean region and through teleconnections can influence the seasonal climate of remote regions. The strong IOD of 2019/2020 influenced the state and predictability of the Northern Hemisphere extratropics. Thus, a good understanding of the mechanism of this teleconnection is desirable. In this contribution we investigate the special teleconnection of the winter 2019/2020. In model experiments with the OpenIFS from ECMWF we show that the NAO in the winter 2019/2020 is influenced by the IOD. We use hindcast ensembles of the DJF season 2019/2020 to analyse this teleconnection. In model experiments, the Sea Surface Temperature (SST) boundary conditions are perturbed. With these experiments we identify the relative importance of individual ocean regions to the state of the NAO in the winter of 2019/2020. We contrast the experiments to the operational ECMWF System5 forecast and ERA5. Experiments with the 2019/2020 SSTs in the Indian Ocean (with other boundary conditions set to climatology) reproduce many of the observed atmospheric 2019/2020 features. In contrast, experiments with SSTs in the Pacific show very different patterns. We identify eddy-mean-flow interactions as a mechanism that connects and transports information from the Indian Ocean to the North Atlantic. With Hoskins E-Vectors we show that anomalous eddy activity during IOD events impacts the position and strength of the Northern Hemisphere extratropical jet. This interaction provides a teleconnection mechanism in addition to the Rossby-wavetrain discussed in other studies. |
format |
Conference Object |
author |
Hempel, T. Weisheimer, A. Palmer, T. |
spellingShingle |
Hempel, T. Weisheimer, A. Palmer, T. The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
author_facet |
Hempel, T. Weisheimer, A. Palmer, T. |
author_sort |
Hempel, T. |
title |
The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
title_short |
The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
title_full |
The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
title_fullStr |
The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
title_full_unstemmed |
The seasonal teleconnections of the Indian Ocean Dipole to the North Atlantic region |
title_sort |
seasonal teleconnections of the indian ocean dipole to the north atlantic region |
publishDate |
2023 |
url |
https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016002 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.57757/IUGG23-0442 https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016002 |
op_doi |
https://doi.org/10.57757/IUGG23-0442 |
_version_ |
1781064234603380736 |