The structure, water budget and radiational features of a high latitude warm front
Hanesiak, J.M., R.E. Stewart, K.K. Szeto, D.R. Hudak, and H.G. Leighton
J.Atmos.Sci.
54, 1553-1573.
Abstract
On September 30, 1994 an Arctic low pressure system passed over
the southern Beaufort Sea area of northern Canada and research
aircraft observations were made within and around the warm front
of the storm. This study is unique in that the warm front contained
sub-zero temperatures across the entire frontal region. The overall
structure of the warm front and surrounding region was similar
to mid latitude storms, however, the precipitation rates, liquid
water content magnitudes, horizontal and vertical winds, vertical
wind shear, turbulence and thermal advection were very weak. In
addition, a low level jet and cloud bands were aligned parallel
to the warm front, near neutral stability occurred within and
around the front and conditional symmetric instability (CSI) was
likely occurring. A steep frontal region resulted from strong
Coriolis influences which in turn limited the amount of cloud
and precipitation ahead of the system. The precipitation efficiency
of the storm was high (60%) but is believed to be highly dependent
on the stage of development. The mesoscale frontogenetic forcing
was primarily controlled by the tilting of isentropic surfaces
with confluence/convergence being the secondary influence. Sublimation
contributions may have been large in the earlier stages of storm
development. Satellite and aircraft radiometers underestimated
cloud top heights by as much as 4 km and this was mostly due to
the near transparency of the lofted ice layer in the upper portion
of the storm. Maximum surface solar radiation deficits ranged
between 91 W m