Robust Amazon precipitation projections in climate models that capture realistic land-atmosphere interactions
Robust Amazon precipitation projections in climate models that capture realistic land-atmosphere interactions
复制标题
气候模型中稳健的亚马逊降水预测可捕捉真实的陆地-大气相互作用
DOI：
10.1088/1748-9326/abfb2e
复制
发表时间：
2021
影响因子：
6.7
通讯作者：
Baker J
中科院分区：
文献类型：
--
作者：
Baker J
陆-气相互作用对亚马逊河流域的降水有重要影响，但在气候模式中对这些过程的评价迄今为止还很有限。我们分析了亚马逊P和蒸散量（ET）之间的关系，在第五耦合模型相互比较项目模型，以评估控制表面水分通量和评估区域P预测的可信度。我们发现，在38个模型中，只有13个模型捕捉到了亚马逊ET的能量限制，与观测结果一致，而20个模型则显示亚马逊ET受到水资源的限制。在历史时期错误地描述对ET的控制的模型预测到2100年亚马逊P的大幅增加和减少，可能被不切实际的陆地-大气相互作用放大。相比之下，未来的变化，在年度和季节尺度亚马逊P被抑制在模型中，模拟现实的控制ET，由于调制陆-气相互作用。通过对模拟不切实际的ET控制的模型的预测进行贴现，我们的分析将全流域未来P变化的不确定性减半。可信模型的合奏平均值显示了强大的干燥信号在亚马逊东部和旱季，和P增加在西部。最后，我们表明，控制亚马逊ET的因素在现实模型中随着时间的推移而演变，降低了气候稳定性，使该地区容易受到进一步变化的影响。
Land–atmosphere interactions have an important influence on Amazon precipitation (P), but evaluation of these processes in climate models has so far been limited. We analysed relationships between Amazon P and evapotranspiration (ET) in the 5th Coupled Model Intercomparison Project models to evaluate controls on surface moisture fluxes and assess the credibility of regional P projections. We found that only 13 out of 38 models captured an energy limitation on Amazon ET, in agreement with observations, while 20 models instead showed Amazon ET is limited by water availability. Models that misrepresented controls on ET over the historical period projected both large increases and decreases in Amazon P by 2100, likely amplified by unrealistic land–atmosphere interactions. In contrast, large future changes in annual and seasonal-scale Amazon P were suppressed in models that simulated realistic controls on ET, due to modulating land–atmosphere interactions. By discounting projections from models that simulated unrealistic ET controls, our analysis halved uncertainty in basin-wide future P change. The ensemble mean of plausible models showed a robust drying signal over the eastern Amazon and in the dry season, and P increases in the west. Finally, we showed that factors controlling Amazon ET evolve over time in realistic models, reducing climate stability and leaving the region vulnerable to further change.