Pacific Oscillation (APO), a dominant mode of atmospheric variability characterized by a seesaw variation in the upper-tropospheric temperature between Asia and the North Pacific, plays important roles in the atmospheric circulation and climate of East Asia. A recent study using state-of-the-art climate models projected a weakening of the winter APO in the expected warmer world of the second half of the 21st century. However, the nature of its relationship with the atmospheric circulation and climate of East Asia in the future remains unknown.
