%0 Journal Article %@ 0022-3670 %A McDonald, NR %A Johnson, ER %D 2009 %F discovery:96866 %I AMER METEOROLOGICAL SOC %J Journal of Physical Oceanography %K WESTERN BOUNDARY CURRENT, POTENTIAL VORTICITY, COASTAL CURRENTS, UNIMAK PASS, FLOW, DYNAMICS, MOTION, VORTEX, TOPOGRAPHY, BARRIERS %N 10 %P 2665 - 2674 %T Gap-Leaping Vortical Currents %U https://discovery.ucl.ac.uk/id/eprint/96866/ %V 39 %X A one-parameter family of exact solutions describing the bifurcation of a steady two-dimensional current with uniform vorticity near a gap in a thin barrier is found. The unsteady evolution of source-driven flows toward these steady states is studied using a version of contour dynamics, appropriately modified to take into account the presence of a barrier with a single gap. It is shown that some of the steady solutions are realizable as large-time limits of the source-driven flows, although some are not owing to persistent eddy-shedding events in the vicinity of the gap. For the special case when there is zero net flux through the gap, numerical experiments show that the through-gap flux of vortical fluid increases with the width of the gap and that this flux approaches a steady limit with time. %Z © Copyright 2009 American Meteorological Society