Global oscillatory modes in high-end climate modeling and reanalyses
Interannual oscillatory modes, atmospheric and oceanic, are present in several large regions of the globe. We examine here low-frequency variability (LFV) over the entire globe in the Community Earth System Model (CESM) and in the NCEP-NCAR and ECMWF ERA5 reanalyses. Multichannel singular spectrum a...
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ftncar:oai:drupal-site.org:articles_24781 2024-04-28T08:27:41+00:00 Global oscillatory modes in high-end climate modeling and reanalyses Feliks, Yizhak (author) Small, Justin (author) Ghil, Michael (author) 2021-12-15 https://doi.org/10.1007/s00382-021-05872-z en eng Climate Dynamics--Clim Dyn--0930-7575--1432-0894 articles:24781 doi:10.1007/s00382-021-05872-z ark:/85065/d75x2dd3 Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. article Text 2021 ftncar https://doi.org/10.1007/s00382-021-05872-z 2024-04-04T17:35:13Z Interannual oscillatory modes, atmospheric and oceanic, are present in several large regions of the globe. We examine here low-frequency variability (LFV) over the entire globe in the Community Earth System Model (CESM) and in the NCEP-NCAR and ECMWF ERA5 reanalyses. Multichannel singular spectrum analysis (MSSA) is applied to these three datasets. In the fully coupled CESM1.1 model, with its resolution of 0.1 x 0.1 degrees in the ocean and 0.25 x 0.25 degrees in the atmosphere, the fields analyzed are surface temperatures, sea level pressures and the 200-hPa geopotential. The simulation is 100-year long and the last 66 yr are used in the analysis. The two statistically significant periodicities in this IPCC-class model are 11 and 3.4 year. In the NCEP-NCAR reanalysis, the fields of sea level pressure and of 200-hPa geopotential are analyzed at the available resolution of 2.5 x 2.5 degrees over the 68-years interval 1949-2016. Oscillations with periods of 12 and 3.6 years are found to be statistically significant in this dataset. In the ECMWF ERA5 reanalysis, the 200-hPa geopotential field was analyzed at its resolution of 0.25 x 0.25 degrees over the 71-years interval 1950-2020. Oscillations with periods of 10 and 3.6 years are found to be statistically significant in this third dataset. The spatio-temporal patterns of the oscillations in the three datasets are quite similar. The spatial pattern of these global oscillations over the North Pacific and North Atlantic resemble the Pacific Decadal Oscillation and the LFV found in the Gulf Stream region and Labrador Sea, respectively. We speculate that such regional oscillations are synchronized over the globe, thus yielding the global oscillatory modes found herein, and discuss the potential role of the 11-year solar-irradiance cycle in this synchronization. The robustness of the two global modes, with their 10-12 and 3.4-3.6 years periodicities, also suggests potential contributions to predictability at 1-3 years horizons. 1852977 Article in Journal/Newspaper Labrador Sea North Atlantic OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Climate Dynamics 57 11-12 3385 3411 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
Interannual oscillatory modes, atmospheric and oceanic, are present in several large regions of the globe. We examine here low-frequency variability (LFV) over the entire globe in the Community Earth System Model (CESM) and in the NCEP-NCAR and ECMWF ERA5 reanalyses. Multichannel singular spectrum analysis (MSSA) is applied to these three datasets. In the fully coupled CESM1.1 model, with its resolution of 0.1 x 0.1 degrees in the ocean and 0.25 x 0.25 degrees in the atmosphere, the fields analyzed are surface temperatures, sea level pressures and the 200-hPa geopotential. The simulation is 100-year long and the last 66 yr are used in the analysis. The two statistically significant periodicities in this IPCC-class model are 11 and 3.4 year. In the NCEP-NCAR reanalysis, the fields of sea level pressure and of 200-hPa geopotential are analyzed at the available resolution of 2.5 x 2.5 degrees over the 68-years interval 1949-2016. Oscillations with periods of 12 and 3.6 years are found to be statistically significant in this dataset. In the ECMWF ERA5 reanalysis, the 200-hPa geopotential field was analyzed at its resolution of 0.25 x 0.25 degrees over the 71-years interval 1950-2020. Oscillations with periods of 10 and 3.6 years are found to be statistically significant in this third dataset. The spatio-temporal patterns of the oscillations in the three datasets are quite similar. The spatial pattern of these global oscillations over the North Pacific and North Atlantic resemble the Pacific Decadal Oscillation and the LFV found in the Gulf Stream region and Labrador Sea, respectively. We speculate that such regional oscillations are synchronized over the globe, thus yielding the global oscillatory modes found herein, and discuss the potential role of the 11-year solar-irradiance cycle in this synchronization. The robustness of the two global modes, with their 10-12 and 3.4-3.6 years periodicities, also suggests potential contributions to predictability at 1-3 years horizons. 1852977 |
author2 |
Feliks, Yizhak (author) Small, Justin (author) Ghil, Michael (author) |
format |
Article in Journal/Newspaper |
title |
Global oscillatory modes in high-end climate modeling and reanalyses |
spellingShingle |
Global oscillatory modes in high-end climate modeling and reanalyses |
title_short |
Global oscillatory modes in high-end climate modeling and reanalyses |
title_full |
Global oscillatory modes in high-end climate modeling and reanalyses |
title_fullStr |
Global oscillatory modes in high-end climate modeling and reanalyses |
title_full_unstemmed |
Global oscillatory modes in high-end climate modeling and reanalyses |
title_sort |
global oscillatory modes in high-end climate modeling and reanalyses |
publishDate |
2021 |
url |
https://doi.org/10.1007/s00382-021-05872-z |
genre |
Labrador Sea North Atlantic |
genre_facet |
Labrador Sea North Atlantic |
op_relation |
Climate Dynamics--Clim Dyn--0930-7575--1432-0894 articles:24781 doi:10.1007/s00382-021-05872-z ark:/85065/d75x2dd3 |
op_rights |
Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
op_doi |
https://doi.org/10.1007/s00382-021-05872-z |
container_title |
Climate Dynamics |
container_volume |
57 |
container_issue |
11-12 |
container_start_page |
3385 |
op_container_end_page |
3411 |
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1797586511976202240 |