The potential of seasonal-to-decadal-scale inter-regional linkages to advance climate predictions (InterDec)

20世纪和21世纪全球平均地表气温（SAT）呈现逐渐变暖的趋势，并叠加了年际和年代际波动。上升趋势包含了人为增加吸热大气温室气体的气候响应。气温在这一趋势中的起伏——在北极尤其明显——主要反映了自然变化。自然气候变化有内部和外部两种类型。前者是由气候系统本身产生的，例如由于海洋环流的变化。后者的一个例子是太阳引起的气候变率。年代际尺度的变化具有很大的社会相关性。例如，在大西洋飓风活动、萨赫勒降雨、印度和东亚季风、欧亚冬季寒冷以及北极SAT和海冰中都可以观察到这种现象。对调节区域极端天气事件发生的年代际气候变率的理解和熟练预测将具有巨大的社会和经济效益。InterDec是一项国际倡议，旨在利用观测数据集和协调的多模式实验，了解世界不同地区年代际气候变率的起源及其之间的联系。一个地区的十年尺度的气候异常如何影响地球上非常遥远的地区？这可以通过大气或海洋的远距连接发生。不同纬向带之间的快速信号通信可以通过大气远距连接在几天或几周内实现，而通过海洋通道的通信则要慢得多，需要数年至数十年甚至更长时间。了解这些过程将加强对平均气候变化和区域极端事件相关趋势的年代际气候预测。来自欧洲不同国家、中国和日本的科学家将密切合作，解开全球十年尺度变化相互关系的秘密。

Globally averaged surface air temperature (SAT) during the 20th and 21st centuries displays a gradual warming and superimposed year-to-year and decadal-scale fluctuations. The upward trend contains the climate response to an anthropogenic increase of heat-trapping atmospheric greenhouse gases. The temperature ups and downs around the trend - that are particularly pronounced in the Arctic - mostly reflect natural variability. Natural climate variations are of two types, internal and external. The former is produced by the climate system itself, e.g. due to variations in ocean circulation. An example of the latter is solar-induced climate variability. Decadal-scale variability is of large societal relevance. It is observed, for example, in Atlantic hurricane activity, Sahel rainfall, Indian and East Asian Monsoons, Eurasian winter coldness and in the Arctic SAT and sea ice. The understanding and skillful prediction of decadal-scale climate variability that modulates the regional occurrence of extreme weather events will be of enormous societal and economic benefit.InterDec is an international initiative aiming at understanding the origin of decadal-scale climate variability in different regions of the world and the linkages between them by using observational data sets and through coordinated multi-model experiments. How can a decadal-scale climate anomaly in one region influence very distant areas of the planet? This can happen through atmospheric or oceanic teleconnections. Fast signal communication between different latitudinal belts within days or weeks is possible through atmospheric teleconnection, whereas communication through oceanic pathways is much slower requiring years to decades or even longer. Understanding these processes will enhance decadal climate prediction of both mean climate variations and associated trends in regional extreme events. Scientists from different European countries, from China and Japan will closely collaborate to disentangle the secrets of the inter-relations of decadal-scale variability around the globe.