A study of links between the Arctic and the midlatitude jet stream using Granger and Pearl causality

This paper investigates causal links between Arctic temperatures and the jet streams. We apply two different frameworks for this application based on the concepts of (1) Granger causality and (2) Pearl causality. Both methods show that Arctic temperature and jet speed and position all exhibit strong autocorrelation, but they also show that these variables are linked together by two robust positive feedback loops that operate on time scales of 5–25 days. The dynamical implications of these feedbacks are discussed. This study is only the beginning of a larger effort to apply and compare different causality methods in order to gain a deeper understanding of the causal connections between the Arctic and weather at lower latitudes.