[4][5][6][7][8] However, other studies, such as those by Watanabe and Hasumi[9] and Vinje,[10] suggested that the Arctic and North Atlantic oscillations did not always explain the variability in sea ice export.
In 2006, the Arctic dipole anomaly was formally proposed by Bingyi Wu, Jia Wang, and John Walsh, using the NCEP/NCAR reanalysis datasets spanning 1960–2002.
[11] This dipole structure leads to a pressure gradient with a zero isopleth oriented from the Bering Strait, across the Arctic to the Greenland and Barents seas.
In contrast, during the negative phase, anomalous winds reduce the removal of sea ice through the Fram Strait.
[13] The Arctic dipole anomaly has also been suggested to play an important role in the occurrence of several extreme sea ice minima that have occurred since the mid-1990s, including the minimum in 2007.