Dominant transport pathways in an atmospheric blocking event

A Lagrangian flow network is constructed for the atmospheric
blocking of eastern Europe and western Russia in summer 2010.
We compute the most probable paths followed by fluid particles
which reveal the {it Omega}-block skeleton of the event. A
hierarchy of sets of highly probable paths is introduced to
describe transport pathways when the most probable path alone
is not representative enough. These sets of paths have the
shape of narrow coherent tubes flowing close to the most
probable one. Thus, even when the most probable path is not
very significant in terms of its probability, it still
identifies the geometry of the transport pathways.