Gap winds in a fjord, part I: Observations and numerical
Peter L. Jackson
D. G. Steyn
Mon. Wea. Rev. 122, 1245-1265, 1994.
Gap winds in Howe Sound, British Columbia are described and placed
in context by reviewing studies of similar phenomena in other
locations. An observational program consisting of a surface meso-
network and vertical soundings, shows that gap winds vary
considerably along and across the channel, as well as vertically.
Wind strength generally increases down channel, and strongest winds
are found below 1000 m depth. Results from application of a 3-dimensional
mesoscale numerical model to a gap wind case compare reasonably
well with observations. Model output reveals more details of
horizontal and especially vertical flow structure than is possible
from observations. Model vertical cross sections and Froude number
output indicate similarity with hydraulic flow. This is further
substantiated by a force balance analysis of model output.