Abstract: A spherical expansion approximation is used to simulate transient maximal radiance of NO gas cloud release and it is time-dependence under a pressure-balancing condition.It is found that if NO gas of 5mol was released at an altitude of 110km the cloud produces luminescent spherical trails as medium intensive aurora However, the cloud brightness descends hastily at 140km. The temperature's decline in the local atmosphere due to a NO₂ gas release in F-region was also simulated.The simulation is completed for 190 and 250km altitudes, 50 and 500mol released amount for both day and night time. A distinct cooling effect is perceptible or bulk of NO₂ release at lower F-region at night