On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth's Radiant Energy Balance
On the Misdiagnosis of Surface Temperature Feedbacks from Variations in Earth's Radiant Energy Balance
复制标题
地球辐射能量平衡变化对地表温度反馈的误诊
作者：
R. Spencer;W. D. Braswell
气候系统对强加的辐射失衡的敏感性仍然是未来人为气候变化预测中不确定性的最大来源。在这里，我们提出了进一步的证据，表明从观测角度来看，这种不确定性很大程度上是由于内部辐射强迫对辐射反馈信号的掩盖，这可能是由于自然云变化造成的。这些内部辐射强迫的存在以及可能的错误反馈诊断通过卫星和耦合气候模型数据的滞后回归分析得到证明，并用简单的强迫反馈模型进行解释。虽然 2000-2010 年期间基于卫星的指标与通过耦合气候模型类似计算的指标在气候敏感性较低的方向上存在很大差异，但我们发现，使用传统方法，不可能准确量化决定气候敏感性的反馈方面的这种差异。结论是，气候系统的大气反馈诊断仍然是一个未解决的问题，这主要是由于卫星辐射收支观测中无法区分辐射强迫和辐射反馈。
The sensitivity of the climate system to an imposed radiative imbalance remains the largest source of uncertainty in projections of future anthropogenic climate change. Here we present further evidence that this uncertainty from an observational perspective is largely due to the masking of the radiative feedback signal by internal radiative forcing, probably due to natural cloud variations. That these internal radiative forcings exist and likely corrupt feedback diagnosis is demonstrated with lag regression analysis of satellite and coupled climate model data, interpreted with a simple forcing-feedback model. While the satellite-based metrics for the period 2000–2010 depart substantially in the direction of lower climate sensitivity from those similarly computed from coupled climate models, we find that, with traditional methods, it is not possible to accurately quantify this discrepancy in terms of the feedbacks which determine climate sensitivity. It is concluded that atmospheric feedback diagnosis of the climate system remains an unsolved problem, due primarily to the inability to distinguish between radiative forcing and radiative feedback in satellite radiative budget observations.