Recent winter precipitation changes over eastern China in different warming periods and the associated East Asian jets and oceanic conditions

The enhanced Siberian high strengthened the East Asian winter monsoon and weakened southwesterly winds over the South China Sea, leading to precipitation decreases over southern China. The westward shift of the East Asian trough enhanced convergence and precipitation over northeastern China. A combination of a negative phase of the interdecadal Pacific oscillation and a positive phase of the Atlantic multidecadal oscillation during 1999-2013 resulted in significant tropospheric warming over the low and high latitudes and cooling over the midlatitudes of East Asia.

These changes enhanced the meridional temperature gradient and thus westerlies over the region between the two jets but weakened them to the south and north of it, thereby contributing to the wind change patterns and the jet displacements.