调节变量和中介变量在欧洲热浪条件事件归因中的作用
On the role of moderator and mediator variables in conditional event attribution of heatwaves over Europe
- University of Bonn（波恩大学）
- Juelich Supercomputing Centre, Forschungszentrum Juelich（于利希超算中心，于利希研究中心）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本研究通过条件化大尺度环流等变量，分析欧洲热浪事件归因的变化，发现调节和中介变量会移除气候变化信号，导致不同归因结论看似矛盾。
中文摘要 AI 辅助
本研究考察了在气候变化下，当分析中包含解释变量时，欧洲热浪事件基于风险的事件归因分析如何发生变化。分析并非仅依赖温度统计，而是在以大尺度环流或先前存在的气候异常为条件的情况下进行。以2006年和2007年炎热的欧洲夏季为例，我们观察到若干系统性效应。控制大气阻塞的存在解释了许多自然温度变率，并大大改善了两年中当前气候与工业化前气候分布之间的分离。在2006年，占主导地位的强阻塞抬高了预期温度，因此相比之下，观测到的异常即使在工业化前气候中也不再显得异常炎热。当这些条件属于气候变化的因果链的一部分时，会出现更复杂的影响，例如作为调节变量或中介变量。通过以这些变量为条件，我们可能移除部分气候变化信号，从而从根本上改变归因研究的结果。我们使用一个简化模型证明，为何带有不同类型条件的归因研究可能得出不同且看似矛盾的结论。
英文摘要
This study examines how a risk-based attribution analysis of European heat wave events under climate change varies when explanatory variables are included in the analysis. Instead of relying solely on temperature statistics, the analysis is conducted while conditioning on large-scale circulation or pre-existing climate anomalies. Using the hot European summers of 2006 and 2007 as examples, we observe several systematic effects. Controlling for the presence of atmospheric blocking explains much of the natural temperature variability and greatly improves the separation of present and pre-industrial distributions in both years. In 2006, the predominant strong blocking raised the expected temperatures, so that, by comparison, the observed anomaly no longer appeared unusually hot, even in a pre-industrial climate. More complex effects occur when the conditions are part of the causal chain of climate change, for example, acting as moderators or mediators. By conditioning on such variables, we may remove part of the climate change signal and thus fundamentally alter the outcome of the attribution study. Using a simplified model we demonstrate why attribution studies with different kinds of conditions can reach different, seemingly contradictory conclusions.
