The Madden-Julian Oscillation (MJO) and northern high latitude wintertime surface air temperatures

The Madden-Julian Oscillation (MJO) is the primary mode of large-scale intraseasonal variability in the tropics. Recent work has connected the MJO to atmospheric variability in mid-latitudes. We focus on relationships between the MJO and wintertime surface air temperatures in the Northern Hemisphere high latitudes. The MJO is diagnosed using principal EOF of 850 hPa zonal winds from the NCEP/NCAR Reanalysis for 1979-2002. Station data are used for surface air temperature in Alaska, Canada, the former U.S.S.R., Greenland, and Iceland. The phase of the MJO has a substantial systematic and spatially coherent effect on intraseasonal variability in wintertime surface air temperature through the global Arctic. Composites of geopotential height and specific humidity suggest that radiative and advective effects are important in the observed connections. These statistical connections may be useful for wintertime temperature forecasts. The mechanisms connecting intraseasonal tropical variability with polar and sub-polar variability bear examination.