Conjecture regarding a strong link between Arctic sea ice loss and Hurricane Sandy emerged in the storm’s immediate aftermath. This was based on observations of weather and climate conditions observed during the time of Sandy, which are described further below. Assumptions of linkages to sea ice were drawn by inferring how those observations fit into a recent proposed theory for how Arctic warming may affect middle latitude weather (Francis and Vavrus 2012, subsequently FV2012).

According to their hypothesis, depleted Arctic sea ice induces a deep tropospheric warming at high latitudes. An attending reduction of the pole-to-equator temperature gradient is then argued to weaken westerly winds at the jetstream level. FV2012 apply linear, steady-state barotropic Rossby wave principles to propose that large-scale atmospheric waves would slow their normal rate of eastward progression as a consequence of weakened westerlies. Further, the authors argue, the slower moving waves would acquire greater meridional amplitude.

Francis, J., and S. Varvus, 2012: Evidence linking Arctic amplification to extreme weather in mid-latitudes. Geophys. Res. Lett., 39, L06801, doi:10.1029/2012GL051000