Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean
The low-frequency atmosphere-ocean coupled variability of the southern Indian Ocean (SIO) was investigated using observation data over 1958-2010. These data were obtained from ECMWF for sea level pressure (SLP) and wind, from NCEP/NCAR for heat fluxes, and from the Hadley Center for SST. To obtain t...
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ftchinacasciocas:oai:ir.qdio.ac.cn:337002/173026 2023-05-15T13:50:09+02:00 Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean Low-Frequency Coupled Atmosphere-Ocean Variability in the Southern Indian Ocean Feng Junqiao Hu Dunxin Yu Lejiang 2012-01-01 http://ir.qdio.ac.cn/handle/337002/173026 英语 eng ADVANCES IN ATMOSPHERIC SCIENCES http://ir.qdio.ac.cn/handle/337002/173026 SEA-SURFACE TEMPERATURE SINGULAR-VALUE DECOMPOSITION DATA ASSIMILATION ANALYSIS AFRICAN SUMMER RAINFALL SST DIPOLE EVENTS INTERANNUAL VARIABILITY NORTHERN-HEMISPHERE CLIMATE VARIABILITY ATLANTIC-OCEAN PART II southern Indian Ocean SST SLP Antarctic Oscillation 期刊论文 2012 ftchinacasciocas 2022-06-27T05:44:51Z The low-frequency atmosphere-ocean coupled variability of the southern Indian Ocean (SIO) was investigated using observation data over 1958-2010. These data were obtained from ECMWF for sea level pressure (SLP) and wind, from NCEP/NCAR for heat fluxes, and from the Hadley Center for SST. To obtain the coupled air-sea variability, we performed SVD analyses on SST and SLP. The primary coupled mode represents 43% of the total square covariance and is featured by weak westerly winds along 45A degrees-30A degrees S. This weakened subtropical anticyclone forces fluctuations in a well-known subtropical dipole structure in the SST via wind-induced processes. The SST changes in response to atmosphere forcing and is predictable with a lead-time of 1-2 months. Atmosphere-ocean coupling of this mode is strongest during the austral summer. Its principle component is characterized by mixed interannual and interdecadal fluctuations. There is a strong relationship between the first mode and Antarctic Oscillation (AAO). The AAO can influence the coupled processes in the SIO by modulating the subtropical high. The second mode, accounting for 30% of the total square covariance, represents a 25-year period interdecadal oscillation in the strength of the subtropical anticyclone that is accompanied by fluctuations of a monopole structure in the SST along the 35A degrees-25A degrees S band. It is caused by subsidence of the atmosphere. The present study also shows that physical processes of both local thermodynamic and ocean circulation in the SIO have a crucial role in the formation of the atmosphere-ocean covariability. Report Antarc* Antarctic Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR Antarctic Austral Indian |
institution |
Open Polar |
collection |
Institute of Oceanology, Chinese Academy of Sciences: IOCAS-IR |
op_collection_id |
ftchinacasciocas |
language |
English |
topic |
SEA-SURFACE TEMPERATURE SINGULAR-VALUE DECOMPOSITION DATA ASSIMILATION ANALYSIS AFRICAN SUMMER RAINFALL SST DIPOLE EVENTS INTERANNUAL VARIABILITY NORTHERN-HEMISPHERE CLIMATE VARIABILITY ATLANTIC-OCEAN PART II southern Indian Ocean SST SLP Antarctic Oscillation |
spellingShingle |
SEA-SURFACE TEMPERATURE SINGULAR-VALUE DECOMPOSITION DATA ASSIMILATION ANALYSIS AFRICAN SUMMER RAINFALL SST DIPOLE EVENTS INTERANNUAL VARIABILITY NORTHERN-HEMISPHERE CLIMATE VARIABILITY ATLANTIC-OCEAN PART II southern Indian Ocean SST SLP Antarctic Oscillation Feng Junqiao Hu Dunxin Yu Lejiang Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
topic_facet |
SEA-SURFACE TEMPERATURE SINGULAR-VALUE DECOMPOSITION DATA ASSIMILATION ANALYSIS AFRICAN SUMMER RAINFALL SST DIPOLE EVENTS INTERANNUAL VARIABILITY NORTHERN-HEMISPHERE CLIMATE VARIABILITY ATLANTIC-OCEAN PART II southern Indian Ocean SST SLP Antarctic Oscillation |
description |
The low-frequency atmosphere-ocean coupled variability of the southern Indian Ocean (SIO) was investigated using observation data over 1958-2010. These data were obtained from ECMWF for sea level pressure (SLP) and wind, from NCEP/NCAR for heat fluxes, and from the Hadley Center for SST. To obtain the coupled air-sea variability, we performed SVD analyses on SST and SLP. The primary coupled mode represents 43% of the total square covariance and is featured by weak westerly winds along 45A degrees-30A degrees S. This weakened subtropical anticyclone forces fluctuations in a well-known subtropical dipole structure in the SST via wind-induced processes. The SST changes in response to atmosphere forcing and is predictable with a lead-time of 1-2 months. Atmosphere-ocean coupling of this mode is strongest during the austral summer. Its principle component is characterized by mixed interannual and interdecadal fluctuations. There is a strong relationship between the first mode and Antarctic Oscillation (AAO). The AAO can influence the coupled processes in the SIO by modulating the subtropical high. The second mode, accounting for 30% of the total square covariance, represents a 25-year period interdecadal oscillation in the strength of the subtropical anticyclone that is accompanied by fluctuations of a monopole structure in the SST along the 35A degrees-25A degrees S band. It is caused by subsidence of the atmosphere. The present study also shows that physical processes of both local thermodynamic and ocean circulation in the SIO have a crucial role in the formation of the atmosphere-ocean covariability. |
format |
Report |
author |
Feng Junqiao Hu Dunxin Yu Lejiang |
author_facet |
Feng Junqiao Hu Dunxin Yu Lejiang |
author_sort |
Feng Junqiao |
title |
Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
title_short |
Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
title_full |
Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
title_fullStr |
Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
title_full_unstemmed |
Low-frequency coupled atmosphere-ocean variability in the southern Indian Ocean |
title_sort |
low-frequency coupled atmosphere-ocean variability in the southern indian ocean |
publishDate |
2012 |
url |
http://ir.qdio.ac.cn/handle/337002/173026 |
geographic |
Antarctic Austral Indian |
geographic_facet |
Antarctic Austral Indian |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
ADVANCES IN ATMOSPHERIC SCIENCES http://ir.qdio.ac.cn/handle/337002/173026 |
_version_ |
1766253132043517952 |