Absolute intensities for the O-2 1.27 mu m continuum absorption

Collision-induced absorption coefficients for the 1.27 mu m band of O-2 hav e been measured at a resolution of 0.5 cm(-1) and an optical path length of 84 m using a Fourier transform spectrometer. Spectra were recorded for sam ple densities rho from 1 to 10 times that of an ideal gas under standard co nditions (T = 273.15 K and P = 101.325 kPa) at temperatures of 253, 273, an d 296 K for pure O-2 and O-2/N-2 mixtures. After removing the contributions from the sharp lines of the nu = 0 <-- 0 component of the O-2 a(1)Delta(g) <-- X(3)Sigma(g)(-) band, which overlaps the continuum band, the integrate d band strength per unit path length, S = S(O2-O2)rho(O2)(2) + S-O2-(N2) rh o(N2)rho(O2), has been determined for several values of the densities, rho( O2) and rho(N2), to give values for SO2-O2 and SO2-N2. At 296 K we find SO2 -O2 = 4.847(22) x 10(-43) cm(-2) (molecule/cm(3))(-2) and SO2-N2 = 0.941(50 ) X 10(-43) cm(-2) (molecule/cm(3))(-2). Type A standard uncertainties are given, that is, +/-1 sigma from a least squares analysis of the integrated- intensity-versus-density data. The S coefficient is in reasonable agreement with the previous measurements of Cho et al. [1963]; however, our value fo r SO2-N2 is 2.6 times greater than their results. Our derived air coefficie nt SO2-air is 37% greater than the atmospheric value of Mlawer et al. [1998 ], after correcting their continuum value for an updated value for the abso rption coefficients for the overlapping discrete structure of the O-2 a(1)D elta(g) <-- X(3)Sigma(g)(-) band.