Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere
The Southern Ocean has a critical influence on the global climate, and any long-term variability in the Southern Ocean can have both regional and global impacts significantly. However, sparse observations limit the study of the long-term variation. To test the quality of models simulating the natura...
Main Author: | |
---|---|
Format: | Thesis |
Language: | unknown |
Published: |
2017
|
Subjects: | |
Online Access: | https://doi.org/10.4225/03/58b649bb7adfa https://figshare.com/articles/thesis/Ocean-atmosphere_coupled_modes_of_decadal_variability_in_the_Southern_Hemisphere/4705477 |
id |
ftmonashunivfig:oai:figshare.com:article/4705477 |
---|---|
record_format |
openpolar |
spelling |
ftmonashunivfig:oai:figshare.com:article/4705477 2023-05-15T18:24:39+02:00 Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere Wang, Gang 2017-03-01T04:10:33Z https://doi.org/10.4225/03/58b649bb7adfa https://figshare.com/articles/thesis/Ocean-atmosphere_coupled_modes_of_decadal_variability_in_the_Southern_Hemisphere/4705477 unknown doi:10.4225/03/58b649bb7adfa https://figshare.com/articles/thesis/Ocean-atmosphere_coupled_modes_of_decadal_variability_in_the_Southern_Hemisphere/4705477 In Copyright Decadal variability Climate modes monash:163683 thesis(doctorate) 1959.1/1227772 ethesis-20151029-100626 2015 Open access Southern Ocean Text Thesis 2017 ftmonashunivfig https://doi.org/10.4225/03/58b649bb7adfa 2022-06-06T15:26:46Z The Southern Ocean has a critical influence on the global climate, and any long-term variability in the Southern Ocean can have both regional and global impacts significantly. However, sparse observations limit the study of the long-term variation. To test the quality of models simulating the natural sea surface temperature (SST) variability, the SST variability in the global oceans is evaluated in simulations of the Climate Model Intercomparison Project Phase 3 (CMIP3) and CMIP5 models. The result shows that some models demonstrate good skill in simulating the observed spatial structure of the SST variability in the tropical domains and less so in the extra-tropical domains. The CMIP5 ensemble exhibits some improvement over the CMIP3 ensemble, mostly in the tropical domains on SST variability simulation. Further, the spatial structure of the SST modes of the CMIP3 and CMIP5 super ensemble is more realistic than any single model, which is mostly used for the following study. Several SST leading modes in the Southern Ocean are discussed on decadal and even larger time scales using CMIP5 data set based on EOF analysis. We compare the modes against several simple null hypotheses, such as isotropic diffusion (red noise) and a Slab Ocean model, to investigate the sources of decadal variability and the factors affecting the propagation and decay of long-term anomalies. The result reveals that the annular mode with largest amplitudes in the Pacific, the basin-wide monopole mode and South Pacific dipole are the principle patterns with low-frequency variability, which contain the dual effects of internal intrinsic processes as well as external forcing and teleconnections. The annular mode is mostly affected by El Niño Southern Oscillation (ENSO) via teleconnection especially in the South Pacific domain and by local Southern Annular Mode (SAM) over the whole Southern Ocean. The monopole mode and South Pacific dipole mode, while they both demonstrate pronounced multi-decadal and longer time scales variability, are firstly ... Thesis Southern Ocean Monash University: Figshare Pacific Southern Ocean |
institution |
Open Polar |
collection |
Monash University: Figshare |
op_collection_id |
ftmonashunivfig |
language |
unknown |
topic |
Decadal variability Climate modes monash:163683 thesis(doctorate) 1959.1/1227772 ethesis-20151029-100626 2015 Open access Southern Ocean |
spellingShingle |
Decadal variability Climate modes monash:163683 thesis(doctorate) 1959.1/1227772 ethesis-20151029-100626 2015 Open access Southern Ocean Wang, Gang Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
topic_facet |
Decadal variability Climate modes monash:163683 thesis(doctorate) 1959.1/1227772 ethesis-20151029-100626 2015 Open access Southern Ocean |
description |
The Southern Ocean has a critical influence on the global climate, and any long-term variability in the Southern Ocean can have both regional and global impacts significantly. However, sparse observations limit the study of the long-term variation. To test the quality of models simulating the natural sea surface temperature (SST) variability, the SST variability in the global oceans is evaluated in simulations of the Climate Model Intercomparison Project Phase 3 (CMIP3) and CMIP5 models. The result shows that some models demonstrate good skill in simulating the observed spatial structure of the SST variability in the tropical domains and less so in the extra-tropical domains. The CMIP5 ensemble exhibits some improvement over the CMIP3 ensemble, mostly in the tropical domains on SST variability simulation. Further, the spatial structure of the SST modes of the CMIP3 and CMIP5 super ensemble is more realistic than any single model, which is mostly used for the following study. Several SST leading modes in the Southern Ocean are discussed on decadal and even larger time scales using CMIP5 data set based on EOF analysis. We compare the modes against several simple null hypotheses, such as isotropic diffusion (red noise) and a Slab Ocean model, to investigate the sources of decadal variability and the factors affecting the propagation and decay of long-term anomalies. The result reveals that the annular mode with largest amplitudes in the Pacific, the basin-wide monopole mode and South Pacific dipole are the principle patterns with low-frequency variability, which contain the dual effects of internal intrinsic processes as well as external forcing and teleconnections. The annular mode is mostly affected by El Niño Southern Oscillation (ENSO) via teleconnection especially in the South Pacific domain and by local Southern Annular Mode (SAM) over the whole Southern Ocean. The monopole mode and South Pacific dipole mode, while they both demonstrate pronounced multi-decadal and longer time scales variability, are firstly ... |
format |
Thesis |
author |
Wang, Gang |
author_facet |
Wang, Gang |
author_sort |
Wang, Gang |
title |
Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
title_short |
Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
title_full |
Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
title_fullStr |
Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
title_full_unstemmed |
Ocean-atmosphere coupled modes of decadal variability in the Southern Hemisphere |
title_sort |
ocean-atmosphere coupled modes of decadal variability in the southern hemisphere |
publishDate |
2017 |
url |
https://doi.org/10.4225/03/58b649bb7adfa https://figshare.com/articles/thesis/Ocean-atmosphere_coupled_modes_of_decadal_variability_in_the_Southern_Hemisphere/4705477 |
geographic |
Pacific Southern Ocean |
geographic_facet |
Pacific Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_relation |
doi:10.4225/03/58b649bb7adfa https://figshare.com/articles/thesis/Ocean-atmosphere_coupled_modes_of_decadal_variability_in_the_Southern_Hemisphere/4705477 |
op_rights |
In Copyright |
op_doi |
https://doi.org/10.4225/03/58b649bb7adfa |
_version_ |
1766205408480854016 |