Revisiting the role of the water vapor and lapse rate feedbacks in the Arctic amplification of climate change
Revisiting the role of the water vapor and lapse rate feedbacks in the Arctic amplification of climate change
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DOI：
10.1175/jcli-d-21-0814.1
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发表时间：
2022-01
影响因子：
4.9
通讯作者：
E. Beer;I. Eisenman
中科院分区：
文献类型：
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作者：
E. Beer;I. Eisenman
造成北极放大全球变暖的过程常常在气候反馈的背景下被描述。有多种方法可以定义气候反馈如何促进北极的放大，这可能会导致显著不同的结果。以前的研究使用了传统的反馈分析框架，将区域表面变暖划分为每个反馈过程的贡献。然而，气候系统中的相互作用可能会使这种划分变得复杂。在这里，我们将重点放在物理直观的方法上，即在强迫变暖期间停用个人反馈过程，并评估由此导致的地表温度场变化。我们使用湿能量平衡模式来研究这一点，该模式具有空间变化的反馈，这些反馈是从综合气候模式结果中指定的。我们发现，当气候变暖归因于每个反馈过程时，如果该过程不活跃，气候将如何变化，水汽反馈是北极地区变暖超过热带的主要原因，而延迟率反馈对北极放大的影响是中性的，它使北极和热带地区的降温幅度大致相同。这些结果与以前的反馈分析截然不同，后者认为延迟率反馈是北极放大的最大贡献因素，而水汽反馈是热带地区变暖超过北极地区的主要相反因素。这凸显了比较分析反馈如何导致气候变暖的不同方法的重要性，以便更好地理解反馈如何影响气候变化。
The processes that contribute to the Arctic amplification of global warming are often described in the context of climate feedbacks. There are multiple ways of defining how a climate feedback contributes to Arctic amplification which can lead to substantially different results. Previous studies have used a traditional feedback analysis framework to partition the regional surface warming into contributions from each feedback process. However, this partitioning can be complicated by interactions in the climate system. Here we focus instead on the physically intuitive approach of inactivating individual feedback processes during forced warming and evaluating the resulting change in the surface temperature field. We investigate this using a moist energy balance model with spatially-varying feedbacks that are specified from comprehensive climate model results. We find that when warming is attributed to each feedback process by comparing how the climate would change if the process were not active, the water vapor feedback is the primary reason that the Arctic region warms more than the tropics, and the lapse rate feedback has a neutral effect on Arctic amplification by cooling the Arctic and the tropics by approximately equivalent amounts. These results are strikingly different from previous feedback analyses, which identified the lapse rate feedback as the largest contributor to Arctic amplification, with the water vapor feedback being the main opposing factor by warming the tropics more than the Arctic region. This highlights the importance of comparing different approaches of analyzing how feedbacks contribute to warming in order to build a better understanding of how feedbacks influence climate changes.