Journal of Tropical Oceanography ›› 2022, Vol. 41 ›› Issue (1): 82-93.doi: 10.11978/2021011CSTR: 32234.14.2021011

Special Issue: 海洋大数据及应用

• Marine Meteorology • Previous Articles     Next Articles

Reconstruction of climate variability of the tropical Indian Ocean based on coral δ18O data from four representative sites

CHEN Yunfan1,2,3(), CHEN Tianran1, LONG Shangmin4, CHEN Zesheng1,2,3, DU Yan1,2,3()   

  1. 1. State Key Laboratory of Tropical Oceanography (South China Sea Institute of Oceanology, Chinese Academy of Sciences), Guangzhou 510301, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China
    3. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
    4. College of Oceanography, Hohai University, Nanjing 210098, China
  • Received:2021-01-25 Revised:2021-04-28 Online:2022-01-10 Published:2021-05-12
  • Contact: DU Yan E-mail:chenyunfan20@mails.;duyan@scsio.ac.cn
  • Supported by:
    National Natural Science Foundation of China(41830538);National Natural Science Foundation of China(42090042);CAS-CSIRO Project(133244KYSB20190031);Global Water Cycle Observatory(183311KYSB20200015);Southern Laboratory of Ocean Science and Engineering(2019BT02H594);Southern Laboratory of Ocean Science and Engineering(GML2019ZD0303)

Abstract:

The coral δ18O data can precisely record climate variation and change of the tropical ocean, making up the shortage of deficient instrumental observations and providing us with the possibility of retrieving long-term paleoclimate conditions. The climate modes of the tropical Indian Ocean influence the climate of the surrounding region and even the globe through ocean-atmosphere interaction; so they are of great significance in climate study. In the present study, coral δ18O data from 1880 to 1999 at four sites located in the tropical Indian Ocean (Kenya, Seychelles, Tanzania, Mentawai) are used to study their ability to reproduce past climate in the tropical Indian Ocean. First, coral δ18O and SST changes are consistent on the long-term trend. Second, coral δ18O coincides nicely with local SST in terms of seasonal cycle, and is more sensitive to SST variation in cold seasons. What is more, coral δ18O at the four sites can describe changes of IOBM (Indian Ocean Basin Mode) and IODM (Indian Ocean Dipole Mode), but the interannual variability of the tropical Indian Ocean recorded by coral δ18O is modulated by interdecadal variation. This study suggests that the δ18O data from coral is an essential indicator of paleoclimate in the tropical Indian Ocean. Different sites' information should be taken into account to reflect past climate change in the Indian Ocean.

Key words: tropical Indian Ocean, coral δ18O, Indian Ocean climate mode, Indian Ocean Basin Mode, Indian Ocean Dipole Mode

CLC Number: 

  • P732.5