Fig. 6: Diagrams of the mechanisms by which East Asia (EA) continental shelf area inundation weakens temperature seasonality over EA.

a Local annual temperature cycle responses to EA continental shelf area inundation. The increase in thermal heat capacity weakens the annual temperature cycle (ATC). The decrease in surface albedo along with cloud‒radiation feedback processes contribute to warming in both winter and summer, increasing the annual mean temperature (MAT). Consequently, winter warming is stronger than summer cooling over the shelf area. b Diagram illustrating negative cloud‒radiation feedback in summer. Cooling in summer weakens local evaporation, thus reducing the amount of cloud over the shelf. Reduced cloud cover increases the shortwave cloud radiation effect, suppressing the cooling of the shelf area. Local cooling then triggers an anomalous anticyclone, further cooling the EA landmass. c Diagram illustrating positive cloud‒radiation feedback in winter. Warming enhances evaporation from the surface. Meanwhile, the ocean has a higher evaporative capacity compared with that of land owing to its higher surface humidity. Water vapor moves upwards, forming more clouds over the shelf area; this reduces outgoing longwave radiation and increases the longwave cloud radiation effect, further enhancing warming. Anomalous southerly winds also strengthen local warming by inducing warm advection.