Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years
We investigated seasonal transition of dominant modes of sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean, analyzing the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis products (NCEP/NCAR reanalyses), the Global sea-Ice and SST...
Published in: | Journal of the Meteorological Society of Japan. Ser. II |
---|---|
Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Meteorological Society of Japan
|
Subjects: | |
Online Access: | http://hdl.handle.net/2115/14527 https://doi.org/10.2151/jmsj.2004.1007 |
id |
fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/14527 |
---|---|
record_format |
openpolar |
spelling |
fthokunivhus:oai:eprints.lib.hokudai.ac.jp:2115/14527 2023-05-15T18:18:37+02:00 Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years TOKINAGA, Hiroki TANIMOTO, Youichi http://hdl.handle.net/2115/14527 https://doi.org/10.2151/jmsj.2004.1007 eng eng Meteorological Society of Japan http://hdl.handle.net/2115/14527 Journal of the Meteorological Society of Japan, 82(4): 1007-1018 http://dx.doi.org/10.2151/jmsj.2004.1007 451 article fthokunivhus https://doi.org/10.2151/jmsj.2004.1007 2022-11-18T01:01:17Z We investigated seasonal transition of dominant modes of sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean, analyzing the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis products (NCEP/NCAR reanalyses), the Global sea-Ice and SST dataset (GISST2.3b), and the Simple Ocean Data Assimilation (SODA). During the coincidence years when the Indian Ocean Dipole (IOD) is followed by the major El Nino during boreal autumn-winter season, surface dipole structure in the tropical Indian Ocean tends to turn into the basinwide warm pattern in the November-December period. In contrast, the subsurface dipole keeps its structure from boreal autumn to winter. Such a surface-confined transition of SSTA is induced by latent heat flux anomalies in the eastern Indian Ocean. These latent heat flux anomalies are associated with changes in scalar wind speed anomalies. The zonal direction of climatological surface winds changes from easterly into westerly over the eastern Indian Ocean in November-December, while the anomalous Walker circulation during the El Nino induces easterly surface wind anomalies to persist there. As a result, deceleration of scalar wind speed takes place during boreal winter, and leads to warming of SST through suppressed evaporation. In addition to these latent heat flux anomalies, incoming solar radiation anomalies contribute to the net surface warming during this period. Furthermore, we discuss the role of the ocean dynamics for keeping the warm SSTAs in the western Indian Ocean. Article in Journal/Newspaper Sea ice Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) Indian Journal of the Meteorological Society of Japan. Ser. II 82 4 1007 1018 |
institution |
Open Polar |
collection |
Hokkaido University Collection of Scholarly and Academic Papers (HUSCAP) |
op_collection_id |
fthokunivhus |
language |
English |
topic |
451 |
spellingShingle |
451 TOKINAGA, Hiroki TANIMOTO, Youichi Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
topic_facet |
451 |
description |
We investigated seasonal transition of dominant modes of sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean, analyzing the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis products (NCEP/NCAR reanalyses), the Global sea-Ice and SST dataset (GISST2.3b), and the Simple Ocean Data Assimilation (SODA). During the coincidence years when the Indian Ocean Dipole (IOD) is followed by the major El Nino during boreal autumn-winter season, surface dipole structure in the tropical Indian Ocean tends to turn into the basinwide warm pattern in the November-December period. In contrast, the subsurface dipole keeps its structure from boreal autumn to winter. Such a surface-confined transition of SSTA is induced by latent heat flux anomalies in the eastern Indian Ocean. These latent heat flux anomalies are associated with changes in scalar wind speed anomalies. The zonal direction of climatological surface winds changes from easterly into westerly over the eastern Indian Ocean in November-December, while the anomalous Walker circulation during the El Nino induces easterly surface wind anomalies to persist there. As a result, deceleration of scalar wind speed takes place during boreal winter, and leads to warming of SST through suppressed evaporation. In addition to these latent heat flux anomalies, incoming solar radiation anomalies contribute to the net surface warming during this period. Furthermore, we discuss the role of the ocean dynamics for keeping the warm SSTAs in the western Indian Ocean. |
format |
Article in Journal/Newspaper |
author |
TOKINAGA, Hiroki TANIMOTO, Youichi |
author_facet |
TOKINAGA, Hiroki TANIMOTO, Youichi |
author_sort |
TOKINAGA, Hiroki |
title |
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
title_short |
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
title_full |
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
title_fullStr |
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
title_full_unstemmed |
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
title_sort |
seasonal transition of sst anomalies in the tropical indian ocean during el nino and indian ocean dipole years |
publisher |
Meteorological Society of Japan |
url |
http://hdl.handle.net/2115/14527 https://doi.org/10.2151/jmsj.2004.1007 |
geographic |
Indian |
geographic_facet |
Indian |
genre |
Sea ice |
genre_facet |
Sea ice |
op_relation |
http://hdl.handle.net/2115/14527 Journal of the Meteorological Society of Japan, 82(4): 1007-1018 http://dx.doi.org/10.2151/jmsj.2004.1007 |
op_doi |
https://doi.org/10.2151/jmsj.2004.1007 |
container_title |
Journal of the Meteorological Society of Japan. Ser. II |
container_volume |
82 |
container_issue |
4 |
container_start_page |
1007 |
op_container_end_page |
1018 |
_version_ |
1766195243795873792 |