Knowledge Bank

Pressure broadened linewidths of the $413-404, 615-606,143 11-152 14$, and $285 23-294 26$ rotational transitions of ozone have been measured, for the foreign gases $N2$ and $O2$, over a pressure range of 200-1000 m Torr. The temperature dependence of the broadening has been measured, for the $413-404$ and $615-606$ transitions, over the range 195-320 K. The air-broadened linewidth, of the $615-606$ transition, was measured at 294 K, and is readily calculated, for other temperatures and transitions, from the $N2$ and $O2$ results. The results are compared with recent theoretical calculations and also with previous measurements, where these are available. These measurements have direct application to the interpretation of observations of microwave emission of middle atmosphere ozone. Mixing ratios of ozone, inferred from such observations, are as much as 15% less using the present results than those inferred using previously available values. The results also serve as reference points for theoretical linewidth calculations applicable from the microwave to the infrared spectral regions.