School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Proc Natl Acad Sci U S A. 2010 Aug 24;107(34):14987-92. doi: 10.1073/pnas.1003336107. Epub 2010 Aug 16.
The observed sea surface temperature in the Southern Ocean shows a substantial warming trend for the second half of the 20th century. Associated with the warming, there has been an enhanced atmospheric hydrological cycle in the Southern Ocean that results in an increase of the Antarctic sea ice for the past three decades through the reduced upward ocean heat transport and increased snowfall. The simulated sea surface temperature variability from two global coupled climate models for the second half of the 20th century is dominated by natural internal variability associated with the Antarctic Oscillation, suggesting that the models' internal variability is too strong, leading to a response to anthropogenic forcing that is too weak. With increased loading of greenhouse gases in the atmosphere through the 21st century, the models show an accelerated warming in the Southern Ocean, and indicate that anthropogenic forcing exceeds natural internal variability. The increased heating from below (ocean) and above (atmosphere) and increased liquid precipitation associated with the enhanced hydrological cycle results in a projected decline of the Antarctic sea ice.
观测到的南大洋海表面温度在 20 世纪后半叶显示出明显的变暖趋势。与变暖相关的是，南大洋大气水文学循环得到增强，这导致过去三十年通过减少向上的海洋热输送和增加降雪，南极海冰增加。两个全球耦合气候模型对 20 世纪后半叶的海表面温度变化的模拟主要由与南极涛动相关的自然内部变率主导，这表明模型的内部变率太强，导致对人为强迫的响应太弱。随着大气中温室气体负荷的增加，模型显示南大洋加速变暖，表明人为强迫超过自然内部变率。来自下方（海洋）和上方（大气）的加热增加以及与增强的水文学循环相关的液态降水增加，导致预计南极海冰减少。
