The earth’s atmosphere is of overwhelming complexity due to a rich interplay between
a large number of phenomena interacting on very diverse length and time
scales. There are mathematical equation systems which, in principle, provide a
comprehensive description of this system. Yet, exact or accurate approximate solutions
to these equations covering the full range of complexities they allow for are not
available. As a consequence, one of the central themes of theoretical meteorology
is the development of simplified model equations that are amenable to analysis and
computational approximate solution, while still faithfully representing an important
subset of the observed phenomena
