A review of Northern Hemisphere winter-time teleconnection patterns

This chapter reviews the major teleconnection patterns that occur in the boreal winter season. The history of teleconnection research is first reviewed emphasising the pioneering work of Sir Gilbert Walker. This is followed by a review of contemporary research that focuses on eleven teleconnection patterns classified into two groups: Euro-Atlantic and Pacific/North American patterns. Structure, impacts on weather and climate and temporal variability of each pattern are discussed by critically comparing major teleconnection studies. The lack of agreement on structure and occasionally the very existence of certain teleconnection patterns is also highlighted. These disagreements can be attributed to the absence of a universally accepted definition of teleconnections and the use of different statistical methods and data sets.