Simple modeling of the temperature dependence of the first-order line-mixing coefficients Y₁(T)

A simple approach is proposed in order to model the temperature dependence of the first-order line-mixing coefficients Y_l(T). It respects a sum rule whose breakdown leads to large errors in atmospheric spectra computations. Furthermore, only two parameters, which can be represented with no more than three significant figures, are required (for air-broadening) for each line. Contrary to previous ones, our model is thus particularly suitable for storage of line-mixing parameters in databases. Tests in the case of two CO₂ Q branches near 14 μm and of O₂ absorption in the centimeter wave region under various pressure and temperature conditions show the accuracy of our approach.