Atmospheric Emission Models: Confrontation between Observational Data and Predictions in the 2.5--300 GHz Frequency Range

Data on atmospheric zenith opacity obtained from a high-altitude (3.8 km) site are compared with detailed atmospheric models available in the literature. The comparison is successful and useful; in fact, it was possible to discriminate among various proposed solutions for both the O2 and the H2O continuum. Moreover, the data at high frequencies indicate that the models probably underestimate by 20 percent the strength of the H2O line at 22 GHz. Also, the 60 GHz O2 band contribution to the total opacity must be reevaluated by 15 percent. The oxygen and water vapor opacities in the 3 cm-0.8 mm range are computed with the best-fitting model for Mauna Kea, Kitt Peak, and the South Pole.