Mesospheric nitric-oxide concentrations during a PCA
Document ID: 46
Narcisi, R. S.
Philbrick, C. Russell
Ulwick, James C.
Gardner, M. E.
USAF, Cambridge Research Laboratories, Hanscom AFB, Bedford, MA, U.S.A.
Abstract
Atmospheric nitric oxide plays a highly significant role in the formation of the ionospheric D and E regions. Measurements of its atmospheric concentration and variability are required, therefore, to determine ionospheric behavior. An upper limit to nitric-oxide concentrations was first set by Jursa et al,. [1959]. Determinations of NO concentrations from rocket-borne ultraviolet spectrometer measurements of the nitricoxide gamma bands were subsequently reported by Barth [1966], Pearce [1969], and Meira [1971]. Apparently, when Rayleigh scattering is properly subtracted from the emission-rate profiles, the NO-concentration profiles derived by Barth and by Pearce can be brought more m line with those of Meira [1971].
A derivation of daytime, nighttime, and sunset mesospheric nitric-oxide concentrations during a PCA is reported in this paper. These concentrations are calculated by utilizing measured ionospheric parameters and ion-chemical reaction rates exclusively. The PCA measurements are briefly discussed, and it is shown how these measurements were instrumental in clarifying the ion chemistry of the disturbed D region. The method of calculation and the measured values of the ionospheric parameters used are discussed. Finally the results are presented and compared to other measurements and determinations.
During the November 2-4, 1969, PCA event at Fort Churchill, Canada, three rocket measurements of the D- and E-region positive ion composition were performed with cryopumped quadrupole mass spectrometers. Measurements of total charged-particle concentrations were also made with Langmuir probes. The first mass spectrometer was launched on November 3 at 0130 CST (x = 133°), the second was fired 10 hours later at 1130 CST (x = 74°), and the third was launched at sunset at 1650 CST (x = 94.6°) on November 4.
Keywords: D-region, E-region, ion composition
| Citation: | "Mesospheric nitric-oxide concentrations during a PCA", Narcisi, R. S., C. R. Philbrick, J. C. Ulwick, M. E. Gardner, Journal of Geophysical Research, Vol. 77, American Geophysical Union (AGU), 1972, pp. 1332 - 1336 |