Reconciling Roles of External Forcing and Internal Variability in Indian Ocean Decadal Variability Since 1920
Reconciling Roles of External Forcing and Internal Variability in Indian Ocean Decadal Variability Since 1920
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DOI：
10.1029/2021gl097198
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发表时间：
2022-04
影响因子：
5.2
通讯作者：
W. Hua;A. Dai;M. Qin
中科院分区：
文献类型：
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作者：
W. Hua;A. Dai;M. Qin
在十年时间尺度上，印度洋海表温度（SST）呈现出整个海盆范围内的连贯变化，但其成因尚未得到很好的理解。在此，我们分析了来自耦合模式比较计划第6阶段和地球系统模式第1版的观测结果和模型模拟，以量化外部强迫和内部气候变率在导致印度洋海表温度十年变化中的作用。结果表明，自1920年以来，外部强迫和内部变率都对印度洋海表温度去线性趋势后的观测到的十年变化有贡献，并且自20世纪50年代以来它们呈现出反相关关系。内部产生的变化源于热带太平洋的远程影响以及内部局地过程可能的贡献，而大西洋多年代际振荡的影响与太平洋年代际振荡的影响相反。由温室气体和气溶胶的非线性变化引起的海表温度十年变化与内部变率大致呈反相关，从而减弱了自20世纪50年代以来观测到的海表温度变化。
On decadal time scales, Indian Ocean sea surface temperatures (SSTs) exhibit coherent basin‐wide changes, but their origins are not well understood. Here we analyze observations and model simulations from Coupled Model Intercomparison Project Phase 6 and Community Earth System Model Version 1 to quantify the roles of external forcing and internal climate variability in causing Indian Ocean decadal SST variations. Results show that both external forcing and internal variability since 1920 have contributed to the observed decadal variations in linearly detrended Indian Ocean SSTs, and they exhibit an out‐of‐phase relationship since the 1950s. The internally‐generated variations arise from remote influences from the tropical Pacific and possible contributions from internal local processes, while the influence from the Atlantic Multidecadal Oscillation is opposite to that of the Interdecadal Pacific Oscillation. Decadal SST changes caused by nonlinear variations in greenhouse gases and aerosols are roughly out‐of‐phase with the internal variability, thus dampening observed SST variations since the 1950s.