The Antarctic continent has not warmed in the last seven decades, despite a monotonic increase in the atmospheric concentration of greenhouse gases. In this paper, we investigate whether the high orography of the Antarctic ice sheet (AIS) has helped delay warming over the continent. To that end, we contrast the Antarctic climate response to CO₂-doubling with present-day orography to the response with a flattened AIS. To corroborate our findings, we perform this exercise with two different climate models. We find that, with a flattened AIS, CO₂-doubling induces more latent heat transport toward the Antarctic continent, greater moisture convergence over the continent and, as a result, more surface-amplified condensational heating. Greater moisture convergence over the continent is made possible by flattening of moist isentropic surfaces, which decreases humidity gradients along the trajectories on which extratropical poleward moisture transport predominantly occurs, thereby enabling more moisture to reach the pole. Furthermore, the polar meridional cell disappears when the AIS is flattened, permitting greater CO₂-forced warm temperature advection toward the Antarctic continent. Our results suggest that the high elevation of the present AIS plays a significant role in decreasing the susceptibility of the Antarctic continent to CO₂-forced warming.

尽管大气中温室气体的浓度单调增加，但过去七十年来，南极大陆并未变暖。在本文中，我们调查了南极冰盖（AIS）的高地形是否有助于延迟该大陆的变暖。为此，我们将南极气候对目前地形的CO ₂倍增响应与平坦的AIS响应进行了对比。为了证实我们的发现，我们使用两种不同的气候模型进行了此练习。我们发现，使用平坦的AIS，CO ₂倍增引起更多的潜热向南极大陆传输，整个大陆上更多的水分汇聚，结果，更多的是表面放大的凝结加热。通过使等熵的潮湿表面变平，可以在整个大陆上实现更大的水分汇聚，这将减少沿主要发生温带极向水汽输送的轨迹的湿度梯度，从而使更多的水分到达极地。此外，当AIS展平时，极地子午线细胞消失，从而使向南极大陆的CO ₂强迫的暖温平流更大。我们的结果表明，目前的AIS高度升高在降低南极大陆对CO ₂的敏感性方面起着重要作用。强迫变暖。