ENSO and QBO modulation of the relationship between Arctic sea ice loss and Eurasian winter climate

Abstract The causality between Arctic sea ice decline and cold boreal winters has been widely debated recently remains controversial. A major source of uncertainty in the ice-cold winter relationship originates from that stratosphere polar vortex (SPV) is not only affected by anomaly but can also be modulated El Niño-Southern Oscillation (ENSO) quasi-biennial oscillation (QBO). Using reanalysis data hindcasts decadal prediction system version 4, here we show both warm occur over Eurasia when Barents–Kara Sea abnormally low. Warm during La Niña-easterly QBO-low (LANINA-EQBO-LICE) years neutral ENSO-neutral QBO (NENSO-NQBO)-LICE Niño (ELNINO)-NQBO-LICE years. During LANINA-EQBO-LICE years, weakened upward-propagating planetary waves troposphere to strengthen SPV then weaken Aleutian low Siberian high, creating conditions favorable for Eurasian warming. atmospheric responses are opposite NENSO-NQBO-LICE ELNINO-NQBO-LICE This implies care should taken using alone as precursor predict climate.