Lower thermospheric nitric oxide concentrations derived from WINDII observations of the green nightglow continuum at 553.1 nm

Vertical profiles of nitric oxide in the altitude range 90 to 105 km are de rived from 553 nm nightglow continuum measurements made with the Wind Imagi ng Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS ). The profiles are derived under the assumption that the continuum emissio n is due entirely to the NO + O air afterglow reaction. Vertical profiles o f the atomic oxygen density, which are required to determine the nitric oxi de concentrations, are derived from coordinated WINDII measurements of the atomic oxygen OI 557.7 nm nightglow emission. Data coverage for local solar times ranging from 20 h to 04 h, and latitudes ranging from 42 degrees S t o 42 degrees N, is achieved by zonally averaging and binning data obtained on 18 nights during a two-month period extending from mid-November 1992 unt il mid-January 1993. The derived nitric oxide concentrations are significan tly smaller than those obtained from rocket measurements of the airglow con tinuum but they do compare well with model expectations and nitric oxide de nsities measured using the resonance fluorescence technique on the Solar Me sosphere Explorer satellite. The near-global coverage of the WINDII observa tions and the similarities to the nitric oxide global morphology establishe d from other satellite measurements strongly suggests that the NO + O react ion is the major source of the continuum near 553 nm and that there is no c ompelling reason to invoke additional sources of continuum emission in this immediate spectral region.