An Anti‐Phase Relationship Between the Subtropical Underwater and Eastern Subtropical Mode Water in the South Pacific During 2004–2020
An Anti‐Phase Relationship Between the Subtropical Underwater and Eastern Subtropical Mode Water in the South Pacific During 2004–2020
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DOI：
10.1029/2021gl096601
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发表时间：
2022-01
影响因子：
5.2
通讯作者：
Yingying Wang-;Tangdong Qu-;Yiyong Luo-;Rana A. Fine-
中科院分区：
文献类型：
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作者：
Yingying Wang-;Tangdong Qu-;Yiyong Luo-;Rana A. Fine-
利用Roemmich-Gilson ARGO资料，研究了2004-2020年南太平洋副热带水下(STUW)和东部副热带模式水(ESTMW)的变化。2004-2013年期间，STUW的数量减少，2013-2020年期间增加，而ESTMW的数量则呈现相反的阶段。在年际时间尺度上，STUW和ESTMW在体积上也存在显著的负相关。这种反相关系归因于它们的体积俯冲速率的变化，而体积俯冲速率又与混合层深度(MLD)的可变性密切相关。ENSO通过修改MLD直接导致俯冲速率的变化。辣度异常沿STUW和ESTMW岩心的等径面向赤道方向传播。下游地区的这些辛辣异常与两个水团的体积变化相关，显著的辛辣异常可以到达热带太平洋。
Using the Roemmich‐Gilson Argo data set, this study investigates variability of the Subtropical Underwater (STUW) and eastern Subtropical Mode Water (ESTMW) in the South Pacific during 2004–2020. The STUW volume decreased during 2004–2013 and increased during 2013–2020, while the volume of the ESTMW shows the opposite phase. On interannual time scales, there is also a significant negative correlation in volume between the STUW and ESTMW. This anti‐phase relationship is attributed to changes in their volumetric subduction rates, which are in turn closely related to variability in the mixed layer depth (MLD). ENSO directly contributes to variability of the subduction rates by modifying the MLD. Equatorward propagation of spiciness anomalies is identified along isopycnal surfaces of the STUW and ESTMW cores. These spiciness anomalies in the downstream region are correlated with changes in volume of both water masses, and significant spiciness anomalies can reach the tropical Pacific.