Häkkinen, S., and G. L. Mellor, 1992: Modeling the seasonal
variability of a coupled arctic ice-ocean system. Journal of Geophysical
Research, 97(C12), 20,285-20,304.
Abstract: Results from modeling studies of the ice-ocean system
in the Arctic Basin and in the Norwegian-Greenland-Barents seas are presented.
We used a three-dimensional coupled ice-ocean model developed at Princeton
University. The ocean model applies the primitive equations and a second
moment turbulence closure for turbulent mixing. The snow-ice model uses
a three-level thermodynamic scheme which resembles Semtner's (1976a) model.
Our conclusions based on the seasonal simulations are as follows. 1) Using
monthly climatological surface heat flux and wind stress, the seasonal
variability of the ice cover is quite realistic in that the thickest ice
is located north of Greenland and the average ice thickness is about 3
m. The largest deviation between the simulated and observed ice cover is
in the Greenland Sea where oceanic conditions detemine the ice edge. Basically,
the monthly climatological forcing does not result in strong enough mixing
to bring sufficient heat from the deep ocean to keep the central Greenland
Sea gyre ice free. The results improve for both the ice cover and ocean
by invoking daily wind forcing for which we first chose year 1987. In the
ocean model, the large mixing events associated with storm passages are
resolved, and as a result, the overall oceanic structure in the Greenland
Sea appears to be more realistic. However, no deep convection takes place
in the model during 1987 which is likely the result of diminished storm
activity in the northern part of the Greenland Sea. The ice thickness field
appears to be very anomalous 1987, so an experiment with 1986 daily wind
forcing was also done, which resulted in an ice thickness field similar
to some reported from other ice models. 2) Both monthly and daily surface
forcing result in a similar behavior of the Atlantic waters in the Arctic
Basin. The Atlantic waters circulate at about the observed level, between
400 and 600 m. The survival of the Atlantic waters in the basin depends
strongly on the heat loss through the ice cover, and it appears that too
much heat is lost on the Eurasian side through the ice because the simulated
Atlantic waters are too cool by about 0.2-0.5°C. 3) For the monthly
climatology case, a large amount of cold and salty water enters the Eurasia
Basin from the Kara and Laptev seas area and finds its way toward the Canada
Basin. This water mass appears to result from ice formation in the Kara
and Laptev seas. When applying the daily forcing, this deep salinity maximum
disappears due to increased mixing on the shelves. Nevertheless, this suggests
a mechanism within the Arctic Ocean as to why the deep Canada Basin is
much aaltier than the Eurasia Basin.