ИСТИНА

Variations of gamma-rays (20 keV – 2.5 MeV) coming from the atmosphere to the surface level are studied since 2009. There are two variation kinds: annual and sporadic. The annual variation is more than 30 % with "winter-spring" depression and summer flat top. The sporadic ones occur under precipitation and up to 60 % over a clear weather level. All kinds of variation are observed different stations: Barentsburg (Spitsbergen), Apatity, Rostov. Concerning to the second kind it is suggested to be caused by electric field in rain (nimbostratus) clouds. Light charged particles gain additional energy in electric field and dissipate it via Bremsstrahlung. Unfortunately there is no opportunity of electric field measure in the clouds during precipitation. However Cosmic Ray Laboratory with FIAN collaboration launches regularly (three times per week) balloons with charged particle detectors. Data of balloon experiment were used to look for correlation between cosmic ray flux in different altitudes and gamma-rays increasing. Hundred and half of launches were used and distinct correlation was not found. The same result is on ground charged particle detectors. The result does not rule out electric field hypothesis. More truly it means that the effect is weak because energy balance shows the energy addition is about hundreds keV against tens MeV of the proper particle energy.