Rapid Surface Warming of the Pacific Asian Marginal Seas Since the Late 1990s

The East Asian marginal seas gain heat from the warm pool via intrusion of the Kuroshio Current and play an important role in regulating regional climate. Here, we show that the sea surface temperature rise of the East Asian marginal seas, especially in areas where the Kuroshio intrudes, has far exceeded the rate of global ocean warming. We attribute this to warming of the Pacific Warm Pool since the 1990s. Intensified trade winds warmed the Pacific Warm Pool and caused the surface Kuroshio and the regions where it intrudes into marginal seas to warm rapidly in the late 1990s. Plain Language Summary In the late 1990s, surface warming signal of the Pacific warm pool entered the East Asia marginal seas via intrusion of the Kuroshio, causing these seas to warm rapidly. The warming of the warm pool is due to an increase in equatorial trade winds, which is attributed to the acceleration of the Walker circulation. The weakening of the mid-latitude westerly winds in the Pacific produced a positive wind stress curl anomaly in the subtropics, and finally weakened the Kuroshio intensity, prompting it to intrude the marginal seas increasingly.