Two Atmospheric Responses to Winter Sea Ice Decline Over the Barents-Kara Seas

The intraseasonal atmospheric responses to winter sea ice decline over the Barents-Kara Seas are examined by dividing rapid sea ice decline events into two categories, based on the direction (upward vs. downward) of the anomalous surface turbulent heat flux (ASTHF) after the sea ice loss. The upward ASTHF events, which could potentially have a large impact on the overlying atmosphere, are characterized by anomalously negative total column water and surface air temperature minus skin temperature, and anomalously positive surface wind speed following the sea ice loss. The downward ASTHF events show opposite features. Both types of events are linked to the Madden-Julian Oscillation and subsequent circulation anomalies. This result indicates that on the intraseasonal time scale, not all sea ice decline events influence the atmosphere, and caution is called for when designing transient model experiments using observed sea ice decline.