  The problem of constructing an asymptotic representation of the solution of
the internal gravity wave field exited by a source moving at a velocity close
to the maximum group velocity of the individual wave mode is considered. For
the critical regimes of individual mode generation the asymptotic
representation of the solution obtained is expressed in terms of a zero-order
Macdonald function. The results of numerical calculations based on the exact
and asymptotic formulas are given.
