On the basis of surface air temperature (SAT) observations from the Great Wall Station located on the Antarctic Peninsula (AP) and ERA-Interim reanalysis data, the present manuscript investigates the role of atmospheric flow at intraseasonal and synoptic time scales in driving the temperature extremes over the AP during austral summer. Both warm and cold events can persist for multiple days and were maintained mainly by the advection of seasonal air temperature by intraseasonal winds. Synoptic winds can influence the temperature change around the peak time through their advection of seasonal temperature, thus determining the time of peak temperature anomalies. The generation of intraseasonal winds was closely associated with Rossby wave trains propagating along the polar front jet over the Atlantic sector of the Southern Ocean before the warm and cold events. The synoptic height anomalies before the warm events were also manifested as Rossby wave trains propagating along the polar front jet. However, synoptic Rossby wave trains were almost absent when the cold events occurred. Further analysis indicates that the weakened background flow during the cold events may have hindered the eastward travel of synoptic eddies. This study provides an important guidance for subseasonal to seasonal prediction on the AP.

On the basis of surface air temperature (SAT) observations from the Great Wall Station located on the Antarctic Peninsula (AP) and ERA-Interim reanalysis data, the present manuscript investigates the role of atmospheric flow at intraseasonal and synoptic time scales in driving the temperature extremes over the AP during austral summer. Both warm and cold events can persist for multiple days and were maintained mainly by the advection of seasonal air temperature by intraseasonal winds. Synoptic winds can influence the temperature change around the peak time through their advection of seasonal temperature, thus determining the time of peak temperature anomalies. The generation of intraseasonal winds was closely associated with Rossby wave trains propagating along the polar front jet over the Atlantic sector of the Southern Ocean before the warm and cold events. The synoptic height anomalies before the warm events were also manifested as Rossby wave trains propagating along the polar front jet. However, synoptic Rossby wave trains were almost absent when the cold events occurred. Further analysis indicates that the weakened background flow during the cold events may have hindered the eastward travel of synoptic eddies. This study provides an important guidance for subseasonal to seasonal prediction on the AP.