Vertical distributions of temperature, salinity, and horizontal and ve
rtical current speed were measured along the edges of a number of rapi
dly freezing leads in the southern central Beaufort Sea during March-A
pril 1992. These observations were restricted to cases having sufficie
ntly small ice water relative speeds that brine-driven convection was
expected, based on scaling arguments, to dominate shear turbulence gen
erated by the relative ice water motion. The observed salinity and cur
rent features were consistent with an existing conceptual model for su
blead convection consequent to brine rejection from ice formation, and
with the results of a numerical model which assumes two-dimensionalit
y in the cross-lead direction, and uses a brine input consistent with
the field observations. These models predict convection of brine-enric
hed plumes beneath the lead downward to the pycnocline, where they the
n spread outward away from the lead. Volume continuity is satisfied by
horizontal inflow of water to the lead at the surface. Observed mean
downward convection speeds varied from 0.2 to 0.7 cm s(-1) and had max
ima up to about 2 cm s(-1), consistent with the numerical model. Salin
ities associated with the convecting parcels were about 0.001 practica
l salinity units (psu) above ambient, which was an order of magnitude
less than predicted by the model, while plumes of water flowing away f
rom the lead on the pycnocline had salinities as high as 0.004 psu abo
ve ambient. These similarities and discrepancies are discussed within
the context of a steady state model versus a nonsteady field situation
, and it is concluded that the steady ''convection cell'' concept is p
robably valid if viewed as a time-averaged sequence of discrete convec
tive plumes or ''thermals.''