Quadratic speed dependence of collisional broadening and shifting for atmospheric applications

- Relations between T and quadratic speed dependence (SD) of collisional parameters.
- Relations between quadratic and hypergeometric SD of collisional width and shift.
- Formula for effective quadratic SD in multi-component gas is given.

Precise analysis of spectroscopic data requires a proper handling of speed-dependent effects on molecular lines. Recently, new fast algorithms implementing a quadratic speed dependence of collisional width and shift were developed. In this report we show, how to evaluate the effective quadratic speed dependence in multi-component gases for atmospheric applications. Moreover, we derived relations between parameters describing quadratic speed dependence and temperature dependence of an averaged collisional width and shift. These relations can be directly applied in molecular spectra analysis and are useful for construction of new generation of spectroscopic databases.