The weakening summer circulation in the Northern Hemisphere mid-latitudes

Abstract

Smaller differences and greater extremes Has recent rapid warming in the Arctic affected weather elsewhere in the world? Coumou et al. find that some key measures of atmospheric circulation in the Northern Hemisphere have weakened during the summer. This change has been caused by the reduction of the temperature difference between mid-latitudes and the North Pole. As summertime circulation has decreased in intensity, episodes of hot weather have become more persistent because there are fewer storms to bring cooler conditions. Science , this issue p. 324