Abstract We have investigated the sensitivity of the Mediterranean atmospheric moisture budget (P-E) to large global mean temperature changes and the mechanisms for its seasonal changes. Model simulations of the Last Glacial Maximum (LGM) and Representative Concentration Pathway rcp8.5 scenario have been compared to pre-Industrial (PI) conditions. We have decomposed (P-E) in thermodynamic, dynamic, transient eddy and surface term. The decomposition revealed that mechanisms for (P-E) changes in the Mediterranean do not follow a simple scaling with temperature from the cold LGM to the warm rcp8.5 and they cannot be described by the thermodynamic contribution associated with the “wet-get-wetter, dry-get-drier” paradigm. Winter changes are caused by the anomalous mean atmospheric circulation. In summer, the thermodynamics provides the largest contribution, but its effect is counteracted by other mechanisms. The Mediterranean response to climate change differs from the averaged behavior of other regions in the same latitudinal belt. The complex spatial interplay of the atmospheric moisture budget contributions results in reduced precipitation in the rcp8.5 and reduced evaporation in the LGM relative to PI. This analysis shows that past (LGM) and future (rcp8.5) atmospheric moisture budget changes have very different basic mechanisms, which cannot be simply linked to changes of global mean temperature.

中文翻译：

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地中海的大气水分收支：末次盛冰期和未来变暖情景中季节性变化的机制

摘要 我们研究了地中海大气水分收支 (PE) 对全球平均温度大变化的敏感性及其季节性变化的机制。最后一次冰期最大值 (LGM) 和代表性浓度路径 rcp8.5 情景的模型模拟已与工业前 (PI) 条件进行了比较。我们已经在热力学、动力学、瞬态涡流和表面项中分解了 (PE)。分解表明，地中海 (PE) 变化的机制并不遵循从冷 LGM 到暖 rcp8.5 的温度的简单缩放，并且它们不能用与“湿变湿”相关的热力学贡献来描述，干变干”范式。冬季的变化是由异常的平均大气环流引起的。在夏天，热力学贡献最大，但其影响被其他机制抵消。地中海对气候变化的响应不同于同一纬度带内其他地区的平均行为。大气水分收支贡献的复杂空间相互作用导致 rcp8.5 中的降水减少和 LGM 中相对于 PI 的蒸发减少。该分析表明，过去（LGM）和未来（rcp8.5）大气水分收支变化具有非常不同的基本机制，不能简单地与全球平均温度的变化联系起来。大气水分收支贡献的复杂空间相互作用导致 rcp8.5 中的降水减少和 LGM 中相对于 PI 的蒸发减少。该分析表明，过去（LGM）和未来（rcp8.5）大气水分收支变化具有非常不同的基本机制，不能简单地与全球平均温度的变化联系起来。大气水分收支贡献的复杂空间相互作用导致 rcp8.5 中的降水减少和 LGM 中相对于 PI 的蒸发减少。该分析表明，过去（LGM）和未来（rcp8.5）大气水分收支变化具有非常不同的基本机制，不能简单地与全球平均温度的变化联系起来。