Projected Antarctic Land Warming and Uncertainty Driven by Atmospheric Heat Transport

Abstract A significant warming is projected in Antarctic climate change under high CO 2 forcing, involving complex interactions between ocean and land surfaces. While previous studies have emphasized the seasonal mechanism driving Antarctic ocean surface warming, the processes governing land surface warming remain less explored. Here we show that, under abrupt quadrupled CO 2 forcing, Antarctic land surface experiences uniform warming throughout the year, primarily driven by poleward atmospheric heat transport, with latent energy transport playing a dominant role. This moisture‐related transport not only delivers energy but also amplifies the water vapor feedback, significantly contributing to the warming. Our findings suggest that the discrepancies in representing these atmospheric processes across models, contribute substantially to the uncertainties in Antarctic land surface warming projections. The result emphasizes the need for improved understanding of the atmospheric dynamics in polar regions to reduce model uncertainties under future climate scenarios.