On a daily variation of cosmic ray flux in the stratosphere

Experimental data on measurements a daily variation of cosmic rays (CR) in the statosphere in different period are presented. Different mechanism of formation of a strong (∼ 4%) observed variation are discussed. Strong daily variations of CR intensity in the stratosphere couldn't be referred to the known mechanisms of daily variations (temperature effect, CR anizotropy effect). Probably, daily variation cause is existence of hypothetic pulsations of CR intensity in the stratosphere with a period of 160 min, typical of variations of many important for CR the Sun and magnetic field characteristics