Spatiotemporal propagating decadal signal of ocean heat content and thermocline depth identified in the tropical Pacific

Min Zhang; Qi Shu; Chang Zhao; Gang Wang; Yuanling Zhang; Yuhuan Xue; Zhenya Song; Zhaohua Wu; Fangli Qiao

doi:10.1016/j.scitotenv.2022.155972

Spatiotemporal propagating decadal signal of ocean heat content and thermocline depth identified in the tropical Pacific

Sci Total Environ. 2022 Sep 10;838(Pt 2):155972. doi: 10.1016/j.scitotenv.2022.155972. Epub 2022 May 16.

Authors

Min Zhang¹, Qi Shu¹, Chang Zhao¹, Gang Wang¹, Yuanling Zhang¹, Yuhuan Xue¹, Zhenya Song¹, Zhaohua Wu², Fangli Qiao³

Affiliations

¹ First Institute of Oceanography, Key Laboratory of Marine Sciences and Numerical Modeling, Ministry of Natural Resources, Qingdao, China; Laboratory for Regional Oceanography and Numerical Modeling, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Shandong Key Laboratory of Marine Sciences and Numerical Modeling, Qingdao, China.
² First Institute of Oceanography, Key Laboratory of Marine Sciences and Numerical Modeling, Ministry of Natural Resources, Qingdao, China; Laboratory for Regional Oceanography and Numerical Modeling, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Department of Earth, Ocean, and Atmospheric Science, Center for Ocean-Atmospheric Prediction Studies, Florida State University, USA.
³ First Institute of Oceanography, Key Laboratory of Marine Sciences and Numerical Modeling, Ministry of Natural Resources, Qingdao, China; Laboratory for Regional Oceanography and Numerical Modeling, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; Shandong Key Laboratory of Marine Sciences and Numerical Modeling, Qingdao, China. Electronic address: qiaofl@fio.org.cn.

PMID: 35588812
DOI: 10.1016/j.scitotenv.2022.155972

Abstract

Tropical Pacific decadal variability (TPDV) and its mechanisms are essential for understanding long-term variations in global climate. The spatiotemporal pattern of this decadal variation has yet to be clarified. Here, on the basis of observational data with the help of the adaptive data analysis method, we extracted and investigated the spatiotemporal evolution of the tropical Pacific decadal variability in upper ocean heat content (UOHC) and thermocline depth. The tropical decadal signal propagated eastward along the equator from the western Pacific to the eastern Pacific after the 1970s, with a speed of 4-5 cm s^-1 yielding a decadal oscillation of approximately 11-13 years. This decadal variability of the thermocline fluctuations (UOHC) was proven to be closely correlated with western wind anomalies since the 1970s and may have been induced by the regime shift of the Pacific decadal oscillation. These peaks of decadal signals corresponded well with the strong El Niño-Southern Oscillation (ENSO) events, reflecting nonlinear rectification of ENSOs on TPDV. Moreover, the TPDV showed a modulating signal on moderate and weak ENSO events.

Keywords: Spatiotemporal evolution; Thermocline depth; Tropical Pacific decadal variability; Upper-ocean heat content.

MeSH terms

El Nino-Southern Oscillation*
Hot Temperature*
Oceans and Seas
Pacific Ocean