Remote influence of Interdecadal Pacific Oscillation on the South Atlantic meridional overturning circulation variability
Remote influence of Interdecadal Pacific Oscillation on the South Atlantic meridional overturning circulation variability
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DOI：
10.1002/2016gl069067
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发表时间：
2016-08-16
影响因子：
5.2
通讯作者：
Campos, Edmo
中科院分区：
文献类型：
--
作者：
Lopez, Hosmay;Dong, Shenfu;Campos, Edmo
本研究利用观测资料、地面强迫海洋模式运行和完全耦合的气候模式运行，探索可能影响南大西洋经向翻转环流(SAMOC)年代际变化的潜在因素。这里我们发现SAMOC与南大西洋海面高度(SSH)变率的领先模有很强的相关性，在20度S的南北方向上表现出一个经向偶极子。南大西洋SSH偶极子变率的很大一部分(类似于45%)受到年代际太平洋涛动(IPO)的远程调制。进一步的分析表明，与IPO相关的热带太平洋对流的异常强迫了强劲的定常Rossby波型，调制了南大西洋的风应力旋度。正(负)位相IPO增加(减少)南大西洋西风，从而增加(减少)南大西洋副热带涡旋的强度，从而增加(减少)SAMOC。
This study explores potential factors that may influence decadal variability of the South Atlantic meridional overturning circulation (SAMOC) by using observational data as well as surface-forced ocean model runs and a fully coupled climate model run. Here we show that SAMOC is strongly correlated with the leading mode of sea surface height (SSH) variability in the South Atlantic Ocean, which displays a meridional dipole between north and south of 20 degrees S. A significant portion (similar to 45%) of the South Atlantic SSH dipole variability is remotely modulated by the Interdecadal Pacific Oscillation (IPO). Further analysis shows that anomalous tropical Pacific convection associated with the IPO forces robust stationary Rossby wave patterns, modulating the wind stress curl over the South Atlantic Ocean. A positive (negative) phase IPO increases (decreases) the westerlies over the South Atlantic, which increases (decreases) the strength of the subtropical gyre in the South Atlantic and thus the SAMOC.