Rosseland mean opacities of air and H-chondrite vapor in meteor entry problems

- Rosseland mean absorption coefficients of air and H-chondrite are given.
- Radiation mechanisms previously not considered are accounted for.
- Temperature and pressure ranges are those expected in entry flights of meteors.
- The calculated coefficient values are larger than the existing values.

The Rosseland mean absorption coefficients are determined for air and the vapor of the H-chondrites for use in calculating the ablation behavior of asteroidal meteoroids. For air, the calculated is made for temperatures between 8000 K and 35,000 K, and for H-chondrites from 3000 K to 20,000 K. Density values of 0.01, 0.1, 1., and 10 kg/m3 are considered. For H-chondrite, O, Si, Mg, Fe, S, O+, Si+, Mg+, S+, O2, SiO, MgO, FeO, and SO are considered as radiators. The latest available data on intensity parameters are used. To ensure accuracy, line profiles are calculated far into the wings. Bound-free absorption by the states of principal quantum numbers equal to or larger than four are accounted for assuming the associated Gaunt factors to be unity. The calculated Rosseland mean absorption coefficient values are substantially larger than the published values, especially at low temperatures.