ABSTRACT

New data on isotope geochemistry of helium as well as more realistic approach to processes in the upper atmosphere stimulated a revision of the aeronomic problem of helium. If we adopt the maximum values of ³He and ⁴He fluxes from the solid earth into the atmosphere (which are equal to 80 and 4.10⁶ atoms/cm² sec, respectively), then a balance of both helium isotopes in the atmosphere can be provided by a mechanism of thermal escape of helium at the average temperature of thermosphere T_a = (1260 ± 40)°K. Possibilities of further study of the problem are discussed.