Some aspects of the impact of the Madden-Julian Oscillation on the state of the Arctic

Many authors have documented variability in the state of the Arctic on a range of time scales, including the intraseasonal. Recent studies have noted the dependence of Arctic surface temperature and circulation on deep convection associated with the leading mode of tropical intraseasonal atmospheric variability, the Madden-Julian Oscillation (MJO). However, very few studies have connected this relationship to the key Arctic parameters of ice and snow extent.

The character of Arctic sea ice and snow cover extent is the result of a complex interrelationship between meteorological and oceaongraphical factors. These parameters have been found to vary on a number of time and spatial scales, including the intraseasonal, and Arctic sea ice and snow extent have been found to be strongly related to both thermodynamic and dynamic forcing on that time scale. Furthermore, several recent studies have found that the leading mode of tropical atmospheric variability on the intraseasonal scale, the MJO, modifies these mid- and high-latitude thermodynamic and dynamic forcing mechanisms. However, the MJO's impact on sea ice and snow cover remains largely unstudied. Therefore, by mapping the dependence of Arctic sea ice and snow cover extent on phase of the MJO, explaining the observed variability via known relationships to atmospheric state variables, and transitioning the results to a statistical prediction model, this proposed research effort fills important gaps in knowledge and prediction of the Arctic system.

Preliminary results for the Arctic show statistically significant modulation of summer sea ice, both volume and extent, by phase of the MJO. These preliminary results will be presented and expanded upon.