Studies of Non-LTE Processes Relating to Atmospheric IR Backgrounds and Clutter.

摘要

This collection of reprints describes work performed under the three basic work elements of the contract during the period 10/01/96-09/30/97. The work elements are: (1) laboratory studies of key production and loss processes for IR-active species of special interest to upper atmospheric non-LTE IR emissions; (2) ground-based field measurements of selected IR airglow and auroral emissions, with emphasis on sources of background and clutter; (3) atmospheric modeling of the dynamics of the non-LTE processes relating to the laboratory and field measurements. Results from the laboratory studies include rate constants for the collisional relaxation of OH(X(sup 2)II, v, N) v = 1 (N = 8-25), v = 2 (N = 8-22), v = 3 (N = 9-17) by O2 and fractional populations of NO(v-1) resulting from collision-induced vibrational relaxation of NO(v = 3) by O atoms and NO (v = 2, 3) by NO. Results from the field measurements include a statistical study of the characteristics of > 50 wave events which were identified in airglow images obtained at equatorial latitudes, documentation of a technique for two-dimensional spectral analyses of mesospheric airglow image data, and the presentation of evidence for ducting and evanescence in selected wave events observed in the airglow over the Hawaiian islands. Results from the modeling effort include the use of ground-based image data for the OI 557.7-nm airglow emission for benchmarks to deduce the presence (and key properties) of wave activity near the base of the thermosphere, followed by use of the dynamical model to estimate the enhanced vertical diffusion resulting from the wave activity.