q 1999 American Meteorological Society The Formation of Coherent Structures in the Context of Blocking

It is shown that the interaction of long, weakly nonlinear, quasigeostrophic baroclinic waves can be described by a pair of linearly coupled Korteweg–de Vries equations. Baroclinic energy conversion is investigated as the interaction of interacting upper- and lower-layer structures, which are represented by solitary waves. This system exhibits a rich dynamics that is suggestive of atmospheric blocking features, such as stable stationary solutions, transient quasi-steady-state solutions, multiple equilibria, and baroclinic instability. This system is investigated both analytically, using techniques from asymptotic perturbation theory, and through numerical simulations. 1