REGIONAL VARIATIONS OF MOIST STATIC ENERGY FLUX INTO THE ARCTIC

The authors investigate the climatological heating of the Arctic by th e atmospheric moist static energy (MSE) flux from lower latitudes base d on 25 years (November 1964-1989) of the GFDL dataset. During the fiv e month winter period (NDJFM) the transport of sensible heat by transi ent eddies is the largest component (50%) at 70 degrees N, followed by the transport of sensible heat by standing eddies (25%), and the mois t static energy flux by the mean meridional circulation (25%). The mea n meridional circulation (MMC) changes from a Ferrel cell to a thermal ly direct circulation near 60 degrees N; maximum horizontal velocities in the thermally direct circulation peak near 70 degrees N. North of 60 degrees N the sensible heat flux by the MMC is southward and oppose s the greater northward transport of geopotential energy. The transpor t of energy is not uniform. Major pathways are the northward transport of positive anomalies through the Greenland and Barents Seas into the eastern Arctic and the southward transport of negative anomalies to t he east of the Siberian high. The Atlantic pathway in winter relates t o transport by transient eddies, while the western Siberian flux relat es to the standing eddy pattern. Interannual variability of northward MSE is concentrated in these two regions. The western Arctic Ocean fro m about 30 degrees to 60 degrees W receives about 50 W m(-2) less ener gy flux convergence than the eastern Arctic. This result compares well with the observed minimum January surface air temperatures in the Can adian Basin of the western Arctic and implies that the greater observe d ice thickness in this region may have a thermodynamic as well as a d ynamic origin.