Regime shift in the Yellow and East China Seas climate dynamics inferred from 1982-2014 sea surface temperature

Abstract

To understand the mechanism of the climate shift in the SST, this study investigates its relationship with the large-scale climate changes around the YECS by using a basin mode estimated from the optimum interpolation SST (OISSTv2) for 34 years (1982&#8722 2014). The leading principal component varies coherently with the Pacific Decadal Oscillation (PDO) during the warming period (1982&#8722 1997) however, its correlation dramatically decreases to an insignificant level after the late 1990s, indicating a potential 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 associated with the variation of the Siberian High along with its intensification, suggesting that the intensified SH pressure system in recent decades has played an increasing role in determining the states of the YECS. These observations 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.ears (1982&#8722 2014). The leading principal component varies coherently with the Pacific Decadal Oscillation (PDO) during the warming period (1982&#8722 1997) however, its correlation dramatically decreases to an insignificant level after the late 1990s, indicating a potential 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 associated with the variation of the Siberian High along with its intensification, suggesting that the intensified SH pressure system in recent decades has played an increasing role in determining the states of the YECS. These observations 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.