Initialization and ensemble generation for decadal climate predictions: A comparison of different methods
Five initialization and ensemble generation methods are investigated with respect to their impact on the prediction skill of the German decadal prediction system "Mittelfristige Klimaprognose" (MiKlip). Among the tested methods, three tackle aspects of model‐consistent initialization using...
Published in: | Journal of Advances in Modeling Earth Systems |
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Format: | Article in Journal/Newspaper |
Language: | English |
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AGU (American Geophysical Union)
2019
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Online Access: | https://oceanrep.geomar.de/id/eprint/45302/ https://oceanrep.geomar.de/id/eprint/45302/13/Polkova_et_al-2019-Journal_of_Advances_in_Modeling_Earth_Systems.pdf https://oceanrep.geomar.de/id/eprint/45302/2/2018ms001439-sup-0001-figure_si-s01_aa.pdf https://doi.org/10.1029/2018MS001439 |
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ftoceanrep:oai:oceanrep.geomar.de:45302 2023-05-15T17:34:48+02:00 Initialization and ensemble generation for decadal climate predictions: A comparison of different methods Polkova, Iuliia Brune, Sebastian Kadow, Christopher Romanova, Vanya Gollan, Gereon Baehr, Johanna Glowienka-Hense, Rita Greatbatch, Richard John Hense, Andreas Illing, Sebastian Köhl, Armin Kröger, Jürgen Müller, Wolfgang A. Pankatz, Klaus Stammer, Detlef 2019-01-17 text https://oceanrep.geomar.de/id/eprint/45302/ https://oceanrep.geomar.de/id/eprint/45302/13/Polkova_et_al-2019-Journal_of_Advances_in_Modeling_Earth_Systems.pdf https://oceanrep.geomar.de/id/eprint/45302/2/2018ms001439-sup-0001-figure_si-s01_aa.pdf https://doi.org/10.1029/2018MS001439 en eng AGU (American Geophysical Union) Wiley https://oceanrep.geomar.de/id/eprint/45302/13/Polkova_et_al-2019-Journal_of_Advances_in_Modeling_Earth_Systems.pdf https://oceanrep.geomar.de/id/eprint/45302/2/2018ms001439-sup-0001-figure_si-s01_aa.pdf Polkova, I. , Brune, S. , Kadow, C. , Romanova, V., Gollan, G. , Baehr, J. , Glowienka-Hense, R., Greatbatch, R. J. , Hense, A. , Illing, S., Köhl, A., Kröger, J., Müller, W. A. , Pankatz, K. and Stammer, D. (2019) Initialization and ensemble generation for decadal climate predictions: A comparison of different methods. Open Access Journal of Advances in Modeling Earth Systems, 11 . pp. 149-172. DOI 10.1029/2018MS001439 <https://doi.org/10.1029/2018MS001439>. doi:10.1029/2018MS001439 cc_by_nc_nd_4.0 cc_by_4.0 info:eu-repo/semantics/openAccess Article PeerReviewed 2019 ftoceanrep https://doi.org/10.1029/2018MS001439 2023-04-07T15:43:05Z Five initialization and ensemble generation methods are investigated with respect to their impact on the prediction skill of the German decadal prediction system "Mittelfristige Klimaprognose" (MiKlip). Among the tested methods, three tackle aspects of model‐consistent initialization using the ensemble Kalman filter (EnKF), the filtered anomaly initialization (FAI) and the initialization method by partially coupled spin‐up (MODINI). The remaining two methods alter the ensemble generation: the ensemble dispersion filter (EDF) corrects each ensemble member with the ensemble mean during model integration. And the bred vectors (BV) perturb the climate state using the fastest growing modes. The new methods are compared against the latest MiKlip system in the low‐resolution configuration (Preop‐LR), which uses lagging the climate state by a few days for ensemble generation and nudging toward ocean and atmosphere reanalyses for initialization. Results show that the tested methods provide an added value for the prediction skill as compared to Preop‐LR in that they improve prediction skill over the eastern and central Pacific and different regions in the North Atlantic Ocean. In this respect, the EnKF and FAI show the most distinct improvements over Preop‐LR for surface temperatures and upper ocean heat content, followed by the BV, the EDF and MODINI. However, no single method exists that is superior to the others with respect to all metrics considered. In particular, all methods affect the Atlantic Meridional Overturning Circulation in different ways, both with respect to the basin‐wide long‐term mean and variability, and with respect to the temporal evolution at the 26° N latitude. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Pacific Journal of Advances in Modeling Earth Systems 11 1 149 172 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
Five initialization and ensemble generation methods are investigated with respect to their impact on the prediction skill of the German decadal prediction system "Mittelfristige Klimaprognose" (MiKlip). Among the tested methods, three tackle aspects of model‐consistent initialization using the ensemble Kalman filter (EnKF), the filtered anomaly initialization (FAI) and the initialization method by partially coupled spin‐up (MODINI). The remaining two methods alter the ensemble generation: the ensemble dispersion filter (EDF) corrects each ensemble member with the ensemble mean during model integration. And the bred vectors (BV) perturb the climate state using the fastest growing modes. The new methods are compared against the latest MiKlip system in the low‐resolution configuration (Preop‐LR), which uses lagging the climate state by a few days for ensemble generation and nudging toward ocean and atmosphere reanalyses for initialization. Results show that the tested methods provide an added value for the prediction skill as compared to Preop‐LR in that they improve prediction skill over the eastern and central Pacific and different regions in the North Atlantic Ocean. In this respect, the EnKF and FAI show the most distinct improvements over Preop‐LR for surface temperatures and upper ocean heat content, followed by the BV, the EDF and MODINI. However, no single method exists that is superior to the others with respect to all metrics considered. In particular, all methods affect the Atlantic Meridional Overturning Circulation in different ways, both with respect to the basin‐wide long‐term mean and variability, and with respect to the temporal evolution at the 26° N latitude. |
format |
Article in Journal/Newspaper |
author |
Polkova, Iuliia Brune, Sebastian Kadow, Christopher Romanova, Vanya Gollan, Gereon Baehr, Johanna Glowienka-Hense, Rita Greatbatch, Richard John Hense, Andreas Illing, Sebastian Köhl, Armin Kröger, Jürgen Müller, Wolfgang A. Pankatz, Klaus Stammer, Detlef |
spellingShingle |
Polkova, Iuliia Brune, Sebastian Kadow, Christopher Romanova, Vanya Gollan, Gereon Baehr, Johanna Glowienka-Hense, Rita Greatbatch, Richard John Hense, Andreas Illing, Sebastian Köhl, Armin Kröger, Jürgen Müller, Wolfgang A. Pankatz, Klaus Stammer, Detlef Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
author_facet |
Polkova, Iuliia Brune, Sebastian Kadow, Christopher Romanova, Vanya Gollan, Gereon Baehr, Johanna Glowienka-Hense, Rita Greatbatch, Richard John Hense, Andreas Illing, Sebastian Köhl, Armin Kröger, Jürgen Müller, Wolfgang A. Pankatz, Klaus Stammer, Detlef |
author_sort |
Polkova, Iuliia |
title |
Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
title_short |
Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
title_full |
Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
title_fullStr |
Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
title_full_unstemmed |
Initialization and ensemble generation for decadal climate predictions: A comparison of different methods |
title_sort |
initialization and ensemble generation for decadal climate predictions: a comparison of different methods |
publisher |
AGU (American Geophysical Union) |
publishDate |
2019 |
url |
https://oceanrep.geomar.de/id/eprint/45302/ https://oceanrep.geomar.de/id/eprint/45302/13/Polkova_et_al-2019-Journal_of_Advances_in_Modeling_Earth_Systems.pdf https://oceanrep.geomar.de/id/eprint/45302/2/2018ms001439-sup-0001-figure_si-s01_aa.pdf https://doi.org/10.1029/2018MS001439 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/45302/13/Polkova_et_al-2019-Journal_of_Advances_in_Modeling_Earth_Systems.pdf https://oceanrep.geomar.de/id/eprint/45302/2/2018ms001439-sup-0001-figure_si-s01_aa.pdf Polkova, I. , Brune, S. , Kadow, C. , Romanova, V., Gollan, G. , Baehr, J. , Glowienka-Hense, R., Greatbatch, R. J. , Hense, A. , Illing, S., Köhl, A., Kröger, J., Müller, W. A. , Pankatz, K. and Stammer, D. (2019) Initialization and ensemble generation for decadal climate predictions: A comparison of different methods. Open Access Journal of Advances in Modeling Earth Systems, 11 . pp. 149-172. DOI 10.1029/2018MS001439 <https://doi.org/10.1029/2018MS001439>. doi:10.1029/2018MS001439 |
op_rights |
cc_by_nc_nd_4.0 cc_by_4.0 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1029/2018MS001439 |
container_title |
Journal of Advances in Modeling Earth Systems |
container_volume |
11 |
container_issue |
1 |
container_start_page |
149 |
op_container_end_page |
172 |
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1766133750693888000 |