Engineering topics

Strobel, D. F.

Publications and source records attributed to Strobel, D. F..

57 records · Page 4

NASA NTRS1977

Measurement of the nitric oxide altitude distribution in the mid-latitude mesosphere

A simple rocket-borne system has been developed for deriving nitric oxide concentration in the mesosphere from measurements of resonantly scattered solar ultraviolet radiation in the NO gamma band near 2150 A. The NO signal is extracted from a background of Rayleigh-scattered light by a direct measurement of this scattered light by use of an NO absorption cell. This system was utilized to measure the NO concentration above White Sands, New Mexico, in the altitude range from 69 to 101 km. The derived NO profile shows a concentration of about 30 million per cu cm at 67 and 100 km with a deep valley (more than an order of magnitude less) at about 84 km. Comparison with model calculations indicates that the time constant for NO chemistry is smaller than or comparable with that for transport.

Baker, K. D.↗

NASA NTRS1976

The aeronomy of odd nitrogen in the thermosphere. II - Twilight emissions

A model developed for the aeronomy of odd nitrogen in the thermosphere is used to analyze rocket measurements of N(4S) and NO densities. Data from Atmosphere Explorer were used to develop a consistent reaction kinetics model for odd nitrogen chemistry. It is concluded that most NO(+) dissociative recombination events must produce N(2D), that N(2D) is quenched by O at a rate of 1 trillionth cu cm per sec, and that the atmospheric O2 quenching rate of N(2D) is consistent with the laboratory rate. The major quenching agent of N(2D) between 140 and 220 km is atomic oxygen, and this reaction is the major source of N(4S). Peak N(4S) densities of about (20-60) million per cu cm at 140-150 km are predicted, with the variability being indicative of the model sensitivity to a factor of 2 change in the O/O2 ratio in the thermosphere.

Strobel, D. F.↗

NASA NTRS1975

Diurnal variations of atomic hydrogen - Observations and calculations

Theoretical calculations of the diurnal variation of atomic hydrogen in the thermosphere are presented that simultaneously evaluate the effects of thermosphere rotation, thermal escape, charge exchange with O(+) ions, charge exchange with hot H(+) ions, transport due to winds, and ballistic fluxes in a consistent manner. The first five effects cause a significant departure from the zero net ballistic flux condition. A thermospheric wind with a peak velocity of 50 m per sec at exobase altitude and a total charge exchange flux varying from 0 to 0.2 billion per sq cm per sec are found to be consistent with the observations.

Tinsley, B. A.↗