Abstract:

Photochemical model is series differential equations that combine ozone density and airglow volume emission rate at oxygen infrared atmospheric band, which can be used to retrieve ozone profile from remotely sensed airglow measurement. The O₂(a¹Δ_g) photochemical model based on atmospheric kinetics and photochemistry of odd oxygen family is overviewed. A new slant path integration method is proposed to calculate optical depth for solving the photolysis coefficients. A practical latitude-altitude-SZA (solar zenith angle) lookup table method for determination photolysis coefficients is introduced to dealing computationally intensive calculations. The results of comparison between conventional and new method for calculating optical depth suggested that, the deviation increases from 12% with SZA of 80° greatly to 100% with SZA of 887°. Especially, comparing to conventional method, it will not lead to minus value by new method. The scheme that establishes a lookup table will avoid the complex procedure, and it allows looking up the coefficients rather than setting parameters and calculating each time.

Key words: odd oxygen family, photochemical model, photolysis coefficient, remote sensing