  The paper considers dynamics in the Charney-Hasegawa-Mima equation, basic to
several different phenomena. In each of them, the generation of poloidal/zonal
flow is important. The paper suggests a possibility to generate such flows
(which can serve as transport barriers). Namely, one needs to create
significant \emph{increment} and \emph{decrement} in neighborhoods of some wave
vectors ${\bf k}_1$ and ${\bf k}_2$ (respectively) such that (1) $R_{{\bf
k}_1}<R_{{\bf k}_2}$, where $R_{\bf k}$ is the spectral density of the extra
invariant ($I=\int R_{\bf k} E_{\bf k} d{\bf k}$ is the extra invariant, with
$E_{\bf k}$ being the energy spectrum), (2) $|{\bf k}_1|<|{\bf k}_2|$, and (3)
${\bf k}_1+{\bf k}_2$ is a poloidal/zonal wave vector. These three conditions
define quite narrow region.
