European climate-change oscillation (ECO)

We identify a latitudinal/seasonal oscillation in the 21st century climate change pattern over Europe ( the European Climate-change Oscillation, or ECO) from the CMIP3 ensemble. The ECO is found in the temperature and precipitation mean and variability change fields, suggesting that it might be a fundamental feature of European climate change. It is associated with a north-south see-saw in the location of an area of increased anticyclonic circulation over the northeastern Atlantic, which induces a seasonally varying northward displacement of the Atlantic storm track. We also define two ECO Indices to measure the ECO based on latitudinal and seasonal climate change gradients. The ECO carries important information on the characteristics of European climate change. It can also be used for regional climate change detection purposes and we find indications of ECO behavior in the temperature change pattern for the latest decades of the 20th century.