Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability
This paper constructs and analyzes a reduced nonlinear stochastic model of extratropical low-frequency variability. To do so, it applies multilevel quadratic regression to the output of a long simulation of a global baroclinic, quasigeostrophic, three-level (QG3) model with topography; the model’s p...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.146.832 2023-05-15T15:07:53+02:00 Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability D. Kondrashov S. Kravtsov M. Ghil The Pennsylvania State University CiteSeerX Archives 2006 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.146.832 http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.146.832 http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf text 2006 ftciteseerx 2016-01-07T15:09:42Z This paper constructs and analyzes a reduced nonlinear stochastic model of extratropical low-frequency variability. To do so, it applies multilevel quadratic regression to the output of a long simulation of a global baroclinic, quasigeostrophic, three-level (QG3) model with topography; the model’s phase space has a dimension of O(10 4). The reduced model has 45 variables and captures well the non-Gaussian features of the QG3 model’s probability density function (PDF). In particular, the reduced model’s PDF shares with the QG3 model its four anomalously persistent flow patterns, which correspond to opposite phases of the Arctic Oscillation and the North Atlantic Oscillation, as well as the Markov chain of transitions between these regimes. In addition, multichannel singular spectrum analysis identifies intraseasonal oscillations with a period of 35–37 days and of 20 days in the data generated by both the QG3 model and its low-dimensional analog. An analytical and numerical study of the reduced model starts with the fixed points and oscillatory eigenmodes of the model’s deterministic part and uses systematically an increasing noise parameter to connect these with the behavior of the full, stochastically forced model version. The results of this study point to the origin of the QG3 model’s multiple regimes and intraseasonal oscillations and identify the connections between the two types of behavior. Text Arctic North Atlantic North Atlantic oscillation Unknown Arctic |
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description |
This paper constructs and analyzes a reduced nonlinear stochastic model of extratropical low-frequency variability. To do so, it applies multilevel quadratic regression to the output of a long simulation of a global baroclinic, quasigeostrophic, three-level (QG3) model with topography; the model’s phase space has a dimension of O(10 4). The reduced model has 45 variables and captures well the non-Gaussian features of the QG3 model’s probability density function (PDF). In particular, the reduced model’s PDF shares with the QG3 model its four anomalously persistent flow patterns, which correspond to opposite phases of the Arctic Oscillation and the North Atlantic Oscillation, as well as the Markov chain of transitions between these regimes. In addition, multichannel singular spectrum analysis identifies intraseasonal oscillations with a period of 35–37 days and of 20 days in the data generated by both the QG3 model and its low-dimensional analog. An analytical and numerical study of the reduced model starts with the fixed points and oscillatory eigenmodes of the model’s deterministic part and uses systematically an increasing noise parameter to connect these with the behavior of the full, stochastically forced model version. The results of this study point to the origin of the QG3 model’s multiple regimes and intraseasonal oscillations and identify the connections between the two types of behavior. |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
D. Kondrashov S. Kravtsov M. Ghil |
spellingShingle |
D. Kondrashov S. Kravtsov M. Ghil Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
author_facet |
D. Kondrashov S. Kravtsov M. Ghil |
author_sort |
D. Kondrashov |
title |
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
title_short |
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
title_full |
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
title_fullStr |
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
title_full_unstemmed |
Empirical Mode Reduction in a Model of Extratropical Low-Frequency Variability |
title_sort |
empirical mode reduction in a model of extratropical low-frequency variability |
publishDate |
2006 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.146.832 http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic North Atlantic North Atlantic oscillation |
genre_facet |
Arctic North Atlantic North Atlantic oscillation |
op_source |
http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.146.832 http://www.atmos.ucla.edu/tcd/PREPRINTS/Kondrashov_EMR_QG3.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766339306927947776 |