Dh. Bromwich et al., NUMERICAL-SIMULATION OF WINTER KATABATIC WINDS FROM WEST ANTARCTICA CROSSING SIPLE COAST AND THE ROSS ICE SHELF, Monthly weather review, 122(7), 1994, pp. 1417-1435
Twenty-four-hour numerical simulations of wintertime surface winds und
er clear sky conditions over the West Antarctic ice sheet and its vici
nity are performed using a hydrostatic, three-dimensional primitive eq
uation model. Two initial states are examined: a state of rest, and a
prescribed pressure field associated with katabatic winds from West An
tarctica propagating across the Ross Ice Shelf. The Antarctic katabati
c winds are mainly due to the strong radiative cooling of the ice slop
es. The West Antarctic terrain is different from that of East Antarcti
ca in two respects: its mean elevation is much lower, and the slope in
the interior is steeper than near the margin at Siple Coast. The simu
lated surface wind regime reveals confluence zones just inland from th
e coast and diffluence zones around the crest of the terrain. The mode
l results suggest that the continuation of katabatic winds beyond coas
tal confluence zones, which are sustained by cold-air drainage in the
interior, has an important impact on airflow over the flat Ross Ice Sh
elf adjacent to the Transantarctic Mountains. The prescribed pressure
disturbance has little impact on the surface winds in the interior but
markedly impacts those over and beyond the gently sloping coastal are
as. Discussion of the impact of the surface wind on the polynya northw
est of the Ross Ice Shelf is also provided. It is shown that the simul
ated surface-wind regime is consistent with the available, mostly surf
ace observational data.