Subthermal nitric oxide spin-orbit distributions in the thermosphere

Details Subthermal nitric oxide spin-orbit distributions in the thermosphere Subthermal nitric oxide spin-orbit distributions in the thermosphere

Nov 1994

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994georl..21.2421l&link_type=abstract

Geophysical Research Letters (ISSN 0094-8276), vol. 21, no. 22, p. 2421-2424

Physics

14

Atmospheric Composition, Atmospheric Radiation, Atoms, Nitric Oxide, Photodissociation, Spatial Distribution, Spectral Emission, Thermosphere, Earth Radiation Budget, Kinetics, Orbits, Remote Sensing, Thermodynamic Equilibrium

Scientific paper

The two NO(X2)pi, upsilon = 1, Omega = 1/2,3/2) spin-orbit populations in the Earth's thermosphere have been found to depart by more than a factor of 2 from the ratio expected from thermal equilibrium. The effective temperature describing the observed population distribution is as much as 700 K lower than the local kinetic temperature. Absolute NO(upsilon = 1, J, Omega) column densities were derived from high-resolution (1/cm) infrared earthlimb spectra for tangent altitudes up to 200 km, obtained in the Cryogenic InfraRed Radiance Instrumentation for Shuttle (CIRRIS) 1A Space Shuttle Experiment. Nonlinear least-squares synthetic spectral fitting was used to analyze the NO delta upsilon = 1 fundamental band emissions near 5.3 micrometers. The spin-orbit distribution represents a third degree of freedom, along with vibration and rotation, that is not in equilibrium with the local kinetic temperature. These observations may significantly impact the interpretation of band-integrated measurements of NO in the upper atmosphere, for which equilibrium sublevel distributions have been assumed. The subthermal distribution is most likely produced in the collisional uppumping of NO(upsilon = 0) by O atoms, which is the major source of NO(upsilon = 1) in the thermosphere. This inference suggests that the present effect is related to the subthermal spin-orbit distributions observed in laboratory studies of NO2 photodissociation.

Affiliated with

Also associated with

No associations

Rating

Subthermal nitric oxide spin-orbit distributions in the thermosphere does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Subthermal nitric oxide spin-orbit distributions in the thermosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Subthermal nitric oxide spin-orbit distributions in the thermosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1024081