Recent cooling trend in the Yellow and East China Seas: A North Pacific climate regime shift

Abstract

The Yellow and East China Seas (YECS) has shown a robust warming during the last several decades. However, after the warming reached its peak in the late 1990s, the sea surface temperature (SST) in the YECS reveals a basin-scale cooling trend. To understand the mechanism of this decadal shift, we investigate the large-scale climate changes in the North Pacific including the YECS and its relation with the decadal changes using a basin mode estimated from the optimum interpolation SST (OISST) for 34 years (1982&#8722 2014). The leading principal mode of the SST coherently varies with the Pacific Decadal Oscillation during the warming period (1982 ~ 1997) however, the correlation significantly decreases after the late 1990s, indicating a potential regime shift in the dynamical linkage between the YECS and the North Pacific. Instead, after the late 1990s, the winter SST in the YECS is more closely correlated with the variation of the Siberian High, suggesting that the intensified Siberian High pressure system in recent decades has played an increasing role in determining the YECS SST. Our findings highlight that the SST variability in the YECS should be viewed as a selective response between the oceanic processes in the North Pacific and atmospheric circulations in the continent across the North Pacific climate regime shift.nd. To understand the mechanism of this decadal shift, we investigate the large-scale climate changes in the North Pacific including the YECS and its relation with the decadal changes using a basin mode estimated from the optimum interpolation SST (OISST) for 34 years (1982&#8722 2014). The leading principal mode of the SST coherently varies with the Pacific Decadal Oscillation during the warming period (1982 ~ 1997) however, the correlation significantly decreases after the late 1990s, indicating a potential regime shift in the dynamical linkage between the YECS and the North Pacific. Instead, after the late 1990s, the winter SST in the YECS is more closely correlated with the variation of the Siberian High, suggesting that the intensified Siberian High pressure system in recent decades has played an increasing role in determining the YECS SST. Our findings highlight that the SST variability in the YECS should be viewed as a selective response between the oceanic processes in the North Pacific and atmospheric circulations in the continent across the North Pacific climate regime shift.