Tunable diode laser measurements of absolute linestrengths in the HNO 3 ν 2 band near 5.8 μm

Abstract

Absolute linestrengths of selected lines in the υ 2 band of HNO 3 have been measured using a tunable diode laser spectrometer operating in a sweep integration mode. The direct measurement technique has been employed to obtain line intensities at 296 K for 22 isolated lines in the 1720–1725 cm -1 region. The reported linestrengths have estimated uncertainties of 4%, a significant portion of this uncertainty arising from spectral interference from hot band transitions. From these linestrength measurements, an integrated band intensity of 1375 cm -2-atm -1 at 296 K is inferred.