|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Environmental Science / Faculty of Environmental Earth Science >
Peer-reviewed Journal Articles, etc >
Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years
| Title: | Seasonal Transition of SST Anomalies in the Tropical Indian Ocean during El Nino and Indian Ocean Dipole Years |
| Authors: | TOKINAGA, Hiroki Browse this author | | TANIMOTO, Youichi2 Browse this author →KAKEN DB |
| Authors(alt): | 谷本, 陽一2 |
| Issue Date: | 25-Aug-2004 |
| Publisher: | Meteorological Society of Japan |
| Journal Title: | Journal of the Meteorological Society of Japan |
| Volume: | 82 |
| Issue: | 4 |
| Start Page: | 1007 |
| End Page: | 1018 |
| Publisher DOI: | 10.2151/jmsj.2004.1007 |
| Abstract: | 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. |
| Type: | article |
| URI: | http://hdl.handle.net/2115/14527 |
| Appears in Collections: | 環境科学院・地球環境科学研究院 (Graduate School of Environmental Science / Faculty of Environmental Earth Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 谷本 陽一
|
