Absolute intensities of 376 16O3 lines in the 9--11 μm region have been determined from high-resolution infrared absorption spectra recorded at room temperature using a Fourier transform spectrometer. The ozone samples were contained in a glass cell having crossed IR-transmitting and UV-transmitting paths, and the UV absorption at 254 nm was used to monitor ozone concentrations in the cell. A multispectrum nonlinear least squares fitting procedure was used to determine intensities for 366 lines in the &ngr;3 fundamental band and 10 lines in the &ngr;1 band. The absolute accuracy of these intensity values ranges from 2% for the strongest, most well determined lines to 4 or 5% for the weakest lines measured. On average, our measured intensities are approximately 1% larger than the values on current spectroscopic databases. ¿ 2001 American Geophysical Union