Possible Associations between the Number of Cold Days over East Asia and Arctic Oscillation and Arctic Warming

Based on the NECP/NCAR reanalysis dataset, associations between number of cold days (NCD) over East Asia (100–150° E, 25–55° N) and Arctic Oscillation (AO)/Arctic warming during 1956–2015 are explored. The results show NCD was closely associated with AO 1956–1990 1991–2015. It reveals showed a downward trend significantly negative correlation in previous stage, while it presented an upward notably positive association later period. Meanwhile increase earlier-stage will often be accompanied by weakness Siberian high (SH), Ural Mountains Blocking (UBH), Asian trough (EAT), “positive–negative–positive” wave band exist upper troposphere, which is linked weakened northerly wind Asia. All these anomalies unfavorable for southward transportation air, eventually leading to decrease Additionally, when near-surface temperature rises period, one hand, SH reinforces further more Asia; other 1000–500 hPa thickness field displays “north positive–south negative” pattern, conducive deceleration westerlies at mid-latitudes Eurasia, bring about enhancement EAT UBH, favoring intrusion finally, generated.