WESTERN NORTH PACIFIC
; SURFACE TEMPERATURE
; EL-NINO
; ANOMALOUS ANTICYCLONE
; SST ANOMALIES
; DIPOLE MODE
; INTERANNUAL VARIABILITY
; SYSTEM MODEL
; CLIMATE
; ENSO
WOS学科分类:
Meteorology & Atmospheric Sciences
WOS研究方向:
Meteorology & Atmospheric Sciences
英文摘要:
The interdecadal variability of basinwide sea surface temperature anomalies (SSTAs) in the tropical Indian Ocean (TIO), referred to as the interdecadal Indian Ocean basin mode (ID-IOBM), is caused by remote forcing of the interdecadal Pacific oscillation (IPO), as demonstrated by the observational datasets and tropical Pacific pacemaker experiments of the Community Earth System Model (CESM). It is noted that the growth of the ID-IOBM shows a season-dependent characteristic, with a maximum tendency of mixed layer heat anomalies occurring in early boreal winter. Three factors contribute to this maximum tendency. In response to the positive IPO forcing, the eastern TIO is covered by the descending branch of the anomalous Walker circulation. Thus, the convection over the southeastern TIO is suppressed, which increases local downward shortwave radiative fluxes. Meanwhile, the equatorial easterly anomalies to the west of the suppressed convection weaken the background mean westerly and thus decrease the upward latent heat fluxes over the equatorial Indian Ocean. Third, anomalous westward Ekman currents driven by the equatorial easterly anomalies advect climatological warm water westward and thus warm the western TIO. In summer, the TIO is out of the control of the positive IPO remote forcing. The ID-IOBM gradually decays due to the Newtonian damping effect.
1.Nanjing Univ Informat Sci & Technol, Collaborat Innovat Ctr Forecast & Evaluat Meteoro, Joint Int Res Lab Climate & Environm Change, Key Lab Meteorol Disaster,Minist Educ, Nanjing, Jiangsu, Peoples R China 2.Chinese Acad Meteorol Sci, State Key Lab Severe Weather, China Meteorol Adm, Beijing, Peoples R China 3.Chinese Acad Sci, Inst Atmospher Phys, State Key Lab Numer Modeling Atmospher Sci & Geop, Beijing, Peoples R China 4.Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA 5.Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Dept Atmospher Sci, Honolulu, HI USA 6.China Univ Geosci, Sch Environm Studies, Dept Atmospher Sci, Wuhan, Hubei, Peoples R China
Recommended Citation:
Huang, Yu,Wu, Bo,Li, Tim,et al. Interdecadal Indian Ocean Basin Mode Driven by Interdecadal Pacific Oscillation: A Season-Dependent Growth Mechanism[J]. JOURNAL OF CLIMATE,2019-01-01,32(7):2057-2073