Distinct Mechanisms of Decadal Subsurface Heat Content Variations in the Eastern and Western Indian Ocean Modulated by Tropical Pacific SST

被引:12
作者
Jin, Xiaolin [1 ]
Kwon, Young-Oh [2 ]
Ummenhofer, Caroline C. [2 ]
Seo, Hyodae [2 ]
Kosaka, Yu [3 ]
Wright, Jonathon S. [1 ]
机构
[1] Tsinghua Univ, Dept Earth Syst Sci, Beijing, Peoples R China
[2] Woods Hole Oceanog Inst, Dept Phys Oceanog, Woods Hole, MA 02543 USA
[3] Univ Tokyo, Res Ctr Adv Sci & Technol, Tokyo, Japan
基金
美国国家科学基金会;
关键词
Air-sea interaction; GLOBAL-WARMING HIATUS; INDONESIAN THROUGHFLOW; CLIMATE VARIABILITY; EL-NINO; SURFACE-TEMPERATURE; SEA-LEVEL; INTERANNUAL VARIABILITY; NATURAL VARIABILITY; EQUATORIAL PACIFIC; OSCILLATION;
D O I
10.1175/JCLI-D-18-0184.1
中图分类号
P4 [大气科学(气象学)];
学科分类号
0706 ; 070601 ;
摘要
Decadal variability of the subsurface ocean heat content (OHC) in the Indian Ocean is investigated using a coupled climate model experiment, in which observed eastern tropical Pacific sea surface temperature (EPSST) anomalies are specified. This study intends to understand the contributions of external forcing relative to those of internal variability associated with EPSST, as well as the mechanisms by which the Pacific impacts Indian Ocean OHC. Internally generated variations associated with EPSST dominate decadal variations in the subsurface Indian Ocean. Consistent with ocean reanalyses, the coupled model reproduces a pronounced east-west dipole structure in the southern tropical Indian Ocean and discontinuities in westward-propagating signals in the central Indian Ocean around 100 degrees E. This implies distinct mechanisms by which the Pacific impacts the eastern and western Indian Ocean on decadal time scales. Decadal variations of OHC in the eastern Indian Ocean are attributed to 1) western Pacific surface wind anomalies, which trigger oceanic Rossby waves propagating westward through the Indonesian Seas and influence Indonesian Throughflow transport, and 2) zonal wind anomalies over the central tropical Indian Ocean, which trigger eastward-propagating Kelvin waves. Decadal variations of OHC in the western Indian Ocean are linked to conditions in the Pacific via changes in the atmospheric Walker cell, which trigger anomalous wind stress curl and Ekman pumping in the central tropical Indian Ocean. Westward-propagating oceanic Rossby waves extend the influence of this anomalous Ekman pumping to the western Indian Ocean.
引用
收藏
页码:7751 / 7769
页数:19
相关论文
共 91 条
[1]  
Alexander MA, 2002, J CLIMATE, V15, P2205, DOI 10.1175/1520-0442(2002)015<2205:TABTIO>2.0.CO
[2]  
2
[3]   Observed temperature trends in the Indian Ocean over 1960-1999 and associated mechanisms [J].
Alory, Gael ;
Wijffels, Susan ;
Meyers, Gary .
GEOPHYSICAL RESEARCH LETTERS, 2007, 34 (02)
[4]  
[Anonymous], 1966, J METEOROL SOC JPN, DOI DOI 10.2151/JMSJ1965.44.1_25
[5]  
BJERKNES J, 1969, MON WEATHER REV, V97, P163, DOI 10.1175/1520-0493(1969)097<0163:ATFTEP>2.3.CO
[6]  
2
[7]  
Butterworth S., 1930, Wirel. Eng., V7, P536
[8]   Shoaling of the off-equatorial south Indian Ocean thermocline: Is it driven by anthropogenic forcing? [J].
Cai, Wenju ;
Sullivan, Arnold ;
Cowan, Tim .
GEOPHYSICAL RESEARCH LETTERS, 2008, 35 (12)
[9]   Transmission of ENSO signal to the Indian Ocean [J].
Cai, WJ ;
Meyers, G ;
Shi, G .
GEOPHYSICAL RESEARCH LETTERS, 2005, 32 (05) :1-4
[10]   Anomalous warming in the Indian Ocean coincident with El Nino [J].
Chambers, DP ;
Tapley, BD ;
Stewart, RH .
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, 1999, 104 (C2) :3035-3047