摘要:

An analysis of the Mariner 6 and 7 occultation data has been completed. Final profiles of temperature, pressure, and electron density have been obtained for the Mariner 6 and 7 entry and exit cases, and results are presented for both the lower atmosphere and the ionosphere. The results of a detailed analysis of the systematic and formal errors introduced at each stage of the data reduction process are also included.At all four occultation points, the lapse rate of temperature was subadiabatic up to altitudes in excess of 20 km. A pronounced temperature inversion was present above the surface at the Mariner 6 exit point. All four profiles exhibit a sharp, superadiabatic drop in temperature at high altitudes, with temperatures falling below the frost point of CO2. These results give a strong indication of frozen CO2in the middle atmosphere of Mars.The analysis for the upper atmosphere indicates peak electron populations of 1.59±0.2×105cm−3near 137 km and 1.73±0.2×103cm−3near 138 km, at the Mariner 6 and 7 entry points, respectively. The plasma scale heights above these maxima were 43±6 and 47±4 km, corresponding to average topside temperatures of 388±54 and 424±35°K, for Mariner 6 and 7 entries,

ISSN:0048-6604    

DOI:10.1029/RS007i005p00525

年代:1972

数据来源: WILEY

摘要:

From simultaneous observations of vertical drift velocity and electron concentration near the dip equator, the photoionization and chemical loss rates for the electrons are deduced. At 300 km, q = 200 to 400 ion‐pairs cm−3sec−1, and β = 2 to 4 × 10−4sec−1. The horizontal plasma transport term of the continuity equation is derived and compared with the corresponding vertical transport term. These terms dominate the electron concentration profiles a

ISSN:0048-6604    

DOI:10.1029/RS007i005p00539

年代:1972

数据来源: WILEY

摘要:

Stable solutions of the ionospheric fields are derived by a modified matrix multiplication technique for a vertical geomagnetic field and large values of the local refractive index. In an alternate method one ignores the coupling between propagating and attenuated magnetoionic modes at large altitudes in the presence of a dipping geomagnetic field. These two methods are used to integrate fields above theFregion and to compute propagation parameters of ELF and VLF waves.The propagation parameters of ELF fields are dependent on the altitude of theFregion and on the geomagnetic field and may exhibit irregular frequency variations. In the VLF range the propagation parameters of terrestrial waves are adequately specified without including the effects of anFregion. Application of the reciprocity theorem for a magnetoionic medium shows that an effective excitation of the terrestrial guide requires satellite sources of excessive dipole moments.

ISSN:0048-6604    

DOI:10.1029/RS007i005p00549

年代:1972

数据来源: WILEY

摘要:

In this paper, the amplitude distributions of the reflected radio waves, from various portions of the traveling ionospheric disturbances (TID) superimposed on small‐scale irregularities, have been studied with the help of simultaneous records of amplitude and phase patterns of vertically reflected echoes. Amplitude distributions of reflected waves, related to different small portions of TID are found to exhibit different types of well‐known distributions, like Rayleigh, Rice, and displaced Gaussian, while resultant distributions corresponding to two successive small portions of the TID may have different shapes, including the familiar M shape reported by many workers. Further, in some events, even three‐peaked amplitude distributions are observed depending upon the ratio of steady component to random component present in the received echo and the nature of the reflecting su

ISSN:0048-6604    

DOI:10.1029/RS007i005p00563

年代:1972

数据来源: WILEY

摘要:

Linear relationships between daytime 30 MHz polar‐cap absorption and the square root of integral and differential proton fluxes have been studied experimentally, using satellite and riometer measurements, and theoretically, by means of power‐law model proton spectrums together with D‐region ionization models developed previously by the author. Relationships of riometer absorption,A, to the 2π omnidirectional integral proton fluxes greater than the threshold energyE0were found to be least sensitive to varying model proton spectrums forE0= 7 Mev. In this case the following formula was computed:A= 0.083[J(>7 Mev)]½db, where the flux units are cm−2sec−1. Using data collected from the 2π omnidirectional integral proton detectors on the polar‐orbiting satellite 1963 38C withE0= 2.2, 8.4, and 25 Mev on 93 passes and polar cap 30 MHz riometer data during three markedly different events, the best linear correlation was found to beA= 0.084[J(>8.4 Mev)]½db with a root‐mean‐square deviation of 0.38 db. Daytime 30 MHz absorption during PCA's is affected most by 15 Mev protons, which produce their greatest ionization at a 65 km alt

ISSN:0048-6604    

DOI:10.1029/RS007i005p00571

年代:1972

数据来源: WILEY

摘要:

Rapid calculations of the dispersion relation can be made for a hot, Maxwellian electron magnetoplasma, with collisions and for any angle β between the wave normal and static magnetic field without using the low‐temperature or the quasi‐static approximations. The dispersion equations ofLewis and Keller[1962] are discussed and interpreted for the purpose of computer programming; these equations are valid for a Vlasov‐Maxwellian plasma and contain a particle‐preserving collision term. Examples of dispersion curves for homogeneous plane waves show: (1) protrusions from some refractive‐index surfaces and (2) the usual multiplicity of solutions for a Maxwellian plasma when the real and imaginary components of the refractive index are of similar magnitude. For a wave frequency 1.11 times the plasma frequency and about 1.78 times the gyrofrequency, a minimum is found in the collisionless damping at β = 0° and a maximum is found at about β = 14°. Three alternatives for the gyroresonance observations on topside ionograms can be found from a study of the dispersion curves near the gyrofrequency: (1) an energy transfer between the highly damped whistler mode and electrons in the vicinity of the sounder, (2) the field resulting from the multiplicity of solutions mentioned above, and (3) an ev

ISSN:0048-6604    

DOI:10.1029/RS007i005p00579

年代:1972

数据来源: WILEY

摘要:

An approximate analytical method is presented for treating electromagnetic scattering from a slender cylindrical conductor buried in a homogeneous conducting half‐space. The excitation is by a uniform line source of current located on the surface. The solution is achieved by an iterative method that accounts for the interaction of the induced current in the cylinder and the air‐earth interface. It is shown that the cylindrical inhomogeneity will distort the profile of the subsurface magnetic field as the horizontal displacement is var

ISSN:0048-6604    

DOI:10.1029/RS007i005p00587

年代:1972

数据来源: WILEY

摘要:

A new method is described for determining the properties of arrays of parallel elements that are at least a wavelength long. This is a first step in a study of the behavior of arrays when the elements are driven by pulsed instead of steady‐state voltages. The new solution for the distributions of current in and driving‐point admittances of the coupled elements makes use of a method of successive approximations in which the boundary condition on the tangential electric field is satisfied separately for the induced and the driven current. The procedure begins with the known solution for an isolated, electrically long antenna and modifies this to take account of the mutual interaction. Graphs of the currents in electrically long two‐ and three‐element arrays are shown, and driving‐point admittances

ISSN:0048-6604    

DOI:10.1029/RS007i005p00593

年代:1972

数据来源: WILEY

摘要:

A solution is developed to calculate the electric field intensity at one point in space due to an electric dipole at another point in space, subject to boundary conditions on a surface of revolution. The solution is valid both external and internal to the surface. Hence, it may be used to compute not only radiated and scattered fields, but also fields internal to resonant cavities. The current on the surface is obtained as an intermediary step. The solution is effected by the method of moments applied to the potential integral equation, and involves inversion of a generalized impedance matrix. The principal limitations to the solution are due to the matrix computation and inversion, which requires that the generating contour be at most several wavelengths long. Some examples of computations for spheres, disks, and conespheres are given.

ISSN:0048-6604    

DOI:10.1029/RS007i005p00603

年代:1972

数据来源: WILEY

摘要:

An earlier experimental result of potential importance toD‐region chemistry and based on the effect of the earth's albedo is being reexamined and reconfirmed by presenting more detailed technical information on the airborne techniques employed. The interpretation of the observations, which consisted of radio soundings, suggests that the energy flux of visible light, distinct from the UV and X‐ray range, has a profound effect on the electron density of theDla

ISSN:0048-6604    

DOI:10.1029/RS007i005p00613

年代:1972

数据来源: WILEY