  We consider a free fermion formulation of a statistical model exhibiting a
limit shape phenomenon. The model is shown to have a phase transition that can
be visualized as the merger of two liquid regions - arctic circles. We show
that the merging arctic circles provide a space-time resolved picture of the
phase transition in lattice QCD known as Gross-Witten-Wadia transition. The
latter is a continuous phase transition of the third order. We argue that this
transition is universal and is not spoiled by interactions if parity and
time-reversal symmetries are preserved. We refer to this universal transition
as the Merger Transition.
