The water vapor absorption in the 195–260 GHz region is investigated using asymptotic line wing theory. A knowledge of the absorption by the H2O lines of the rotational band where the shape of the line wing provides an adequate description of the water vapor absorption data in the 300–1000 cm-1 interval is not enough to reproduce the absorption data for the microwave region. While asymptotic line wing theory treats the absorption by any colliding molecular pairs and ignores that due to bound dimers, the experimental absorption data reveal the fraction of absorption by the bound water dimers. The role of the local spectral line contribution to the evaluation of the dimer absorption is discussed.
The applicability of the ck-correlation approximation for certain spectral intervals in the 9.6 μm O3 band is examined. The problems of the optical thickness correlation and of the ck-correlation approximation assessment are discussed.
The self-broadened H2O continuum absorption data for the 3−5 μm window available in the literature are described in the framework of asymptotic line wing theory. Use is made of a diffusion model taking into account violation of the long-wave approximation in spectral line wings.
To model the signals of magnetic and frequency scanning of the rarefied gas, the problem of resonant interaction of two monochromatic waves and particles with active transition J = 0↔J = 1 in stationary magnetic field is solved by method of density matrix. The resonance with the sign depending on gas pressure, waves’ intensity and magnetic field strength was found for the system with a split ground state. Solution of wave equations for slow amplitudes.