Intraseasonal influences on terrestrial snow cover in the Arctic

With the recent changes in sea ice extent, the effects of periodic atmospheric oscillations in the Arctic have become of greater interest to the Arctic community. For example, Northern Hemisphere snow and sea ice have been found to vary by phase of the Arctic Oscillation (AO)/North Atlantic Oscillation (NAO) and the Pacific-North American Pattern (PNA), and recent work suggests this variability changes over time. Finding connections between atmospheric oscillations like the AO, NAO, and PNA and variances in Arctic temperature and circulation facilitates the prediction of both sea ice extent and snow cover. Despite work on the seasonal and decadal time scales, less is known about the influence of shorter-term, lower-latitude oscillations on the Arctic cryosphere. However, one tropical/sub-tropical atmospheric oscillation that has recently been shown to affect atmospheric circulation, temperature, and even sea ice extent in the Arctic is the Madden-Julian Oscillation (MJO). Its effect on northern hemisphere terrestrial snow cover, nevertheless, remains largely unknown.

This research explores teleconnections between the MJO and the high latitudes, specifically by observing how Arctic terrestrial snow cover varies in accordance with the phases of the MJO on a seasonal time scale. Snow data was obtained and analyzed from NSIDC's Interactive Multisensor Snow (IMS) daily Northern Hemisphere snow analysis at 24 km resolution. Daily data from December, January and February and from August, September, and October were selected as representative months for the winter and summer seasons, respectively. Snow cover patterns within the designated seasons were compared and correlated with the eight phases of the MJO. Variability of snow cover by MJO phase along with corresponding variability in atmospheric circulation will be presented.