Role of Atmospheric Variability in Driving the “Warm-Arctic, Cold-Continent” Pattern Over the North America Sector and Sea Ice Variability Over the Chukchi-Bering Sea Geophysical Research Letters

While the observed decline of sea ice over the Chukchi-Bering Sea (CBS) has coincided with the “warm-Arctic, cold-continent” (WACC) pattern over the North America (NA) sector, there is a debate on the causes of the WACC pattern. Here we present a very similar WACC pattern over the NA sector on both interannual and subseasonal time scales. Lead-lag regression analyses on the shorter time scale indicate that an anomalous anticyclonic circulation over Alaska/Yukon in conjunction with the downward surface turbulent heat flux and long-wave radiation anomalies over CBS leads the formation of the WACC pattern by about 1–2 days, while the latter further leads CBS sea ice reduction by about 3 days. These results indicate that atmospheric variability may play an active role in driving both the WACC pattern over NA and CBS sea ice variability. Grant no. NA15OAR4310098 Grant no. NA15OAR4310177 Grant no. NA17OAR4310261