Gravity current, and bores is the lower atmosphere play an important part in deter mining mesoscale weather events quilt generally. Researches into then phenomena on Cape York Peninsula have shed light on the behaviour of boll, In rather quiet and otherwise undisturbed conditions. The part played by sea-breezes in initiating bores was strongly suggested by field observations, but a decisive demonstration of the exact sequence of events resulting in a bore was not found. A series of numerical experiments has been carried out and these have shown clearly what happens when two sea-breeze circulations of different provenance interact. Under conditions commonly prevailing on the Peninsula in October, this collision or interaction of sea-breezes is both observed and found by two-dimensional numerical modeling to occur. When two sea-breere fronts collide, or one overtakes the other, cool sea-breeze modified boundary-layer air Is forced upward to form a hump of relatively cool air. This process continue until a condition for bore formation is met. At that pate, in general, two born are formed. moving with approximately the respective velocities of the sea-breeze fronts before collision. New insight has also been obtained into the behaviour of sea-breeze surges in the tropics, in the presence of clear skies and a coast-normal geostrophic wind. Under suitable conditions, they can be deeper and more powerful than is generally supposed, and can penetrate much further inland in some cases, and in others out to sea. Coast-parallel geostrophic wind components have link effect on this penetration, nor does a hill or escarpment near the coast.
R. H. Clarke (Sat,) studied this question.