Previous work has shown that estimates of climate sensitivity vary over time in response to abrupt CO₂ forcing in climate model simulations. The energy fluxes that drive warming in response to increasing CO₂ also influence precipitation, which prompts the question: Does the precipitation response therefore also vary over time? We investigate by examining the response of precipitation to warming forced by greenhouse gases—the hydrological sensitivity—in a set of millennial-length climate simulations with multiple climate models, Long Run Model Intercomparison Project (LongRunMIP). We compare hydrological sensitivity calculated from three different timescales of the simulations: years 1–20, 21–150, and 151–1000. We show that the hydrological sensitivity lacks a consistent dependence on timescale, in contrast to climate sensitivity. Decomposition of the surface energy budget reveals that the relative muting of the multi-model mean hydrological sensitivity is driven by surface downwelling shortwave flux.

中文翻译：

---

千年气候模拟中降水响应对 CO2 诱导变暖的时间尺度依赖性


以前的研究表明，在气候模式模拟中，对气候敏感性的估计值会随着时间而变化，以响应突然的 CO₂ 强迫。响应 CO₂ 增加而驱动变暖的能量通量也会影响降水，这就提出了一个问题：降水响应是否也随时间而变化？我们通过在一组具有多个气候模式的千年长气候模拟中检查降水对温室气体强迫变暖的响应（水文敏感性）进行研究，即长期模式比较计划 （LongRunMIP）。我们比较了从模拟的三个不同时间尺度计算的水文敏感性：1-20 年、21-150 年和 151-1000 年。我们表明，与气候敏感性相比，水文敏感性缺乏对时间尺度的一致依赖性。地表能量收支的分解表明，多模式平均水文敏感性的相对阻尼是由地表短波通量驱动的。