Journal Article

Projected Antarctic Land Warming and Uncertainty Driven by Atmospheric Heat Transport

Hu, Xiaoming, Zhang, Yihan, Yang, Song, Wang, Peixi

2025

Overview

A significant warming is projected in Antarctic climate change under high CO2 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 CO2 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. Plain Language Summary To project the surface warming of Antarctic under high‐emission scenarios, we utilize the pre‐industrial and abrupt quadrupled CO2 (abrupt‐4 × CO2) experiments from 18 Coupled Model Intercomparison Project Phase 6 models. The surface temperature response is analyzed using the climate feedback‐response analysis method. Our research highlights significant warming differences between the ocean and land surfaces: the ocean surface exhibits strong winter warming and weak summer warming attributable to the seasonal energy transfer mechanism; in contrast, land surface warming is relatively weak and more uniform throughout the year, primarily driven by poleward atmospheric heat transport (AHT), with latent energy (LE) transport playing a central role in both energy delivery and the amplification of water vapor (WV) feedback. The inter‐model spread in land warming is closely tied to the variations in the strength of AHT, particularly the transport of LE, which influences regional WV content. Understanding these mechanisms is crucial for advancing future climate changes in the Antarctic region. Key Points Meridional Atmospheric heat transport (AHT), particularly latent energy (LE) transport, serves as the primary driver of Antarctic land warming LE transport delivers heat to Antarctic land surface, boosting moisture and amplifying the regional water vapor feedback The uncertainty in Antarctic land warming projections is closely linked to variations in the strength of AHT

• Publisher: John Wiley & Sons, Inc,Wiley
• Subject: Antarctic climate / Antarctic climate changes / Antarctic climate projection / Antarctic zone / Atmospheric dynamics / atmospheric heat transport / Atmospheric processes / Carbon dioxide / Climate change / Climate feedback / Climate models / climate projection uncertainty / Climatic analysis / Energy transfer / Energy transport / Feedback / Future climates / Heat / Heat transport / Intercomparison / Ocean surface / Ocean warming / Oceans / Polar environments / Polar regions / Response analysis / Surface temperature / Uncertainty / Water vapor / Water vapour