Generalized Malkmus line intensity distribution for CO2 infrared radiation in Doppler broadening regime

A new line intensity distribution function is introduced in order to improve the accuracy of statistical narrow-band (SNB) models in the Doppler line broadening regime and in a wide temperature range. This distribution function generalizes the Malkmus distribution through a parameter enabling to adjust the contribution of small line intensities. This new model is shown to enhance significantly SNB accuracy for CO₂ uniform column radiation, especially at low temperatures. For non-uniform columns, Lindquist-Simmons type approximations are derived for this new intensity distribution. Their results are in much closer agreement with line by line results than Curtis-Godson approximation ones when steep temperature gradients are considered.