A comparative analysis of spatiotemporal instability development under non-steady state thermal self-action and filamentation of high-power laser radiation in turbulent atmosphere has been performed. It is shown that filamentation forms perturbations of the light field, whose scale is independent on the size of the refractive index fluctuations in turbulent atmosphere, which initiated these fluctuations. Advanced instability of the light field is determined by aberration defocusing on thermal lenses under thermal blooming and on plasma lenses under laser pulse filamentation.
spatiotemporal instability, thermal blooming, femtosecond filamentation, turbulent atmosphere