Impact of El Niño–Southern Oscillation on European climate

El Niño–Southern Oscillation (ENSO) is arguably the most important global climate pattern. While the effects in the Pacific–North American sector and the tropical regions are relatively well understood, the impacts on the circulation in the North Atlantic–European sector are discussed more controversially. Studies from the past 10 years demonstrate that ENSO does affect European climate. However, some of the effects undergo a seasonal modulation or are nonlinear. The signal can be modified by other factors and might be nonstationary on multidecadal scales, contributing to a large interevent variability. Here I review observational and model‐based evidence for ENSO's effect on European climate and discuss possible mechanisms, also including troposphere‐stratosphere coupling. The paper ends with a schematic depiction of the effects and a discussion of their relevance with respect to our scientific understanding of the climate system and of their relevance for seasonal climate forecasts.