Nonequilibrium infrared radiation and natural laser effect in the Venus and Mars atmospheres

Processes of excitation of vibrational levels of CO2 molecules in the Venus and Mars atmospheres by direct solar radiation in 10.6; 9.4; 4.3; 2.7 and 2.0 μm bands were investigated using the model of partial vibrational temperatures and in the ''radiation entrainment'' approximation. The effect of direct (without participation of progressive degrees of freedom) conversion of solar radiation, absorbed in the near region of the infrared spectrum band (lambda < or approximately 4.3 μm) into the natural radiation of the atmospheres in 10.6 and 9.4 μm bands was revealed. It was found that the level of nonequilibrium IR radiation exists in these bands. The sighting in the tangential directions gives the level maxima at the height of approximately 108 km for the Venus and approximately 60 km for the Mars with intensity in subsolar point equal to approximately 2300 and 320 ergxcm-2xs-1, respectively. It is shown that inverse population of the 00 deg 1 and 10 deg 0 levels, providing approximately 5 to 50% radiation intensification per one passage during sighting in the tangential directions, exists at heights of z > or approximately 115 km for the Venus and z > or approximately 70 km for the Mars. Thus, both the Venus and Mars can be assigned to the first natural laser objects of the IR band