bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle fluxes in the outer geomagnetic field
Authors: Vernov S. N. , Gorchakov E. V. , Kuznetsov S. N. , Logachev Yu. I. , Sosnovets E. N. , Stolpovsky V. G. 
Published: February 2008

The outer geomagnetic field comprises the outer radiation belt, consisting of electrons with energies of 104–107 ev, and the unstable radiation zone. The outer radiation belt is bounded on its inner side by a gap, which is at various times located at a distance of 2.2–3.5 RE and in which a considerable precipitation of electrons from radiation belts occurs, possibly owing to a high intensity of electromagnetic waves. The boundary separating the outer radiation belt from the unstable radiation zone is at λ ∼ 71° and ∼9 RE in the equatorial plane on the sunlit side, and at 7–8 RE in the equatorial plane on the nightside. Beyond this, the unstable radiation zone extends out to the magnetosphere boundary and up to λ ∼ 77° on the sunlit side, and out to 14–15 RE on the nightside. The relatively rapid electron intensity variations with periods of 1–7 days are essentially absent at distances less than that of the outer belt but are distinctly seen in the outer belt. In the unstable radiation zone the intensity of electrons with energies of the order of 105 ev changes by several times, and good correlation is observed with the increase in Kp. Analysis of the outer belt data shows that this belt is formed partly by electron diffusion into the magnetosphere (like the belt of protons with energies of 105–107 ev) and partly by the simultaneous acceleration of electrons at various distances from the earth.A comparison of electron intensity changes with the solar activity cycle shows little or no correlation for electrons with Ee > 40 kev. The intensity of electrons with Ee > 500 kev has changed significantly; in 1964 it was 30 times lower than in 1959. The absence of significant dependence of the diffusion coefficients for electrons with E ∼ 104–105 ev on the phase of the solar activity cycle shows that the relatively weak magnetic disturbances that do not change with the phase of the cycle are of major importance in diffusion. This suggests that these magnetic disturbances appear at great distances from the sun because of the instabilities of plasma itself and, therefore, that they depend little on solar activity.
Interplanetary dust measurements near the Earth
Authors: Bandermann L. W. , Singer S. Fred 
Published: February 2008

The impact of dust particles on space vehicles near the earth gives important information about interplanetary dust. Satellite impact measurements have been made with two types of detectors: acoustic and penetration detectors. These types of detectors correspond to momentum and energy restrictions, respectively, on the impact rate of dust. The early acoustic data showed a greatly enhanced rate near the earth, which suggested that there was a high concentration near the earth (‘dust belt’). Quite to the contrary, from theory no sensible enhancement in concentration can be derived but, instead, a moderate enhancement in impact rate, depending on the geocentric velocity of the particles. The dust belt would therefore exist only as a consequence of the measurement technique.Here we review the theory that allows us to calculate the following, for a given geocentric velocity of dust particles and a distribution of velocities (all isotropic) : (1) the concentration; (2) the flux; and (3) the impact rate (momentum‐ and energy‐limited) at various distances from the earth and for various detector velocities so as to bracket all possible experimental situations. With the use of these results, it is then possible to analyze and compare results from different experiments. Of the experimental data reviewed, both U. S. and Russian, only certain are selected for a more detailed analysis. The theory accounts well for the observed penetration data in space vehicles flown near the earth and the moon; they lead to a zodiacal dust model similar to van de Hulst's model, having a particle population predominantly in the micron and decamicron size range (rather than submicron), with a flat (rather than steep) size distribution, and with geocentric velocities of 5 to 15 km/sec.A theoretical analysis is also presented for a nonisotropic velocity distribution. This is of practical importance for very small particles, which are partly supported by solar radiation pressure and therefore develop a streaming velocity with respect to the earth; in addition, the earth itself introduces an asymmetry, since its orbital velocity varies throughout the year. Numerical results are given for predicted asymmetries in concentration, influx of dust into the atmosphere, and in the satellite impact rates. Impact rates from some satellites exhibited such asymmetries, and these cases support the hypothesis that the heliocentric dust orbits have small inclination and small eccentricity. These results are inconclusive because the data are scant; a systematic analysis of all available impact data with respect to asymmetries is needed.
Tropical meteorology
Authors: Yanai Michio 
Published: February 2008

In the past few years we have witnessed a tremendous expansion of the scope of tropical meteorology. Advances in satellite technology and numerical simulation of the global general circulation have made it impossible to maintain the isolation of this classical branch of meteorology from the rest of the atmospheric sciences.During the years 1971–1974 the data obtained by many pre‐Garp experiments became available for scientific analysis. The experiments include the Line Islands Experiment (Lie) in 1967, the Florida State University Barbados Experiment in 1968, the Atlantic Trade Wind Experiment (Atex) and the Barbados Oceanographic and Meteorological Experiment (Bomex) in 1969, and the Venezuelan International Meteorological and Hydrological Experiment (Vimhex) in 1969 and 1972. The data from these experiments prompted especially studies of the structure of trade wind subcloud layer.
Progress in atmospheric electricity
Authors: Uman Martin A. , Dawson George A. , Hoppel William A. 
Published: February 2008

This report will concentrate on highlights of the work done in atmospheric electricity during the period 1971–1975, although an extensive bibliography is included for reference purposes. For convenience, the report has been (arbitrarily) divided into sections on fair‐weather and global electricity, cloud electricity, and lightning.It is useful to divide fair‐weather and global electricity into the following areas: (1) ions, aerosols, and radioactivity, (2) boundary layer effects, (3) global circuit and free atmosphere electricity, and (4) applications of atmospheric electricity.
Earthquake source mechanisms and plate tectonics
Authors: Kanamori Hiroo 
Published: February 2008

This review and the accompanying references will be concerned mainly with earthquake source studies pertinent to plate tectonics. Studies on geological problems, lithospheric flexure and mantle convection are discussed in other reviews in this volume.In the earlier stage of the development of plate tectonics, the distribution of earthquakes and the geometrical configuration of earthquake source mechanisms played an important role. As more sophisticated techniques for retrieving earthquake source parameters (synthetic seismogram method for both body and surface waves, inversion method, matching filter method, etc.) were developed, emphasis in the last four years was placed on the determination of not only the geometry of the source but also more quantitative parameters such as the stress drop, the amount of slip, the complexity, the strength of non‐isotropic components, and the spectral characteristics. Also significant emphasis was placed on intraplate earthquakes and events on continental plate boundaries.
Hydromagnetic waves in the magnetosphere
Authors: Hughes W. J. 
Published: February 2008

The study of hydromagnetic waves in the magnetosphere has seen some notable advances over the last four years. We owe a large debt to the IMS observational programs both in space and on the ground. These programs have produced extremely valuable data sets which should be worked on for many years to come.The improvement in instrumentation has been a major factor in observational work. The new generation of spacecraft are exemplified by the ISEE and GEOS missions, both of which have novel aspects. Both missions have played a large part in helping us understand how important heavy ions are in the propagation of hydromagnetic waves of all frequencies. The dual spacecraft, ISEE 1 and ISEE 2, are helping to unravel the spatial structure of these waves in space, while both missions are providing the first measurements of electric field oscillations associated with hydromagnetic waves. The ionospheric electric field measurements made by the STARE radar system have introduced a new dimension to the field, and help provide a link between ground based and spacecraft measurements. Several ground based magnetometer networks were either introduced or expanded, largely as a result of the IMS.
Waves and instabilities
Authors: Inan Umran S. 
Published: February 2008

This review concentrates on U. S. research activities in the area of waves and instabilities during the mid‐1982 to mid‐1986 period. Plasma waves and instabilities are phenomena that are central to the energization, acceleration, transport, and loss of energetic particles in magnetized plasmas. As such, they play a dominant role in almost all energy exchange phenomena that occur in planetary magnetospheres.It is difficult to give a comprehensive review of the subject even for a limited period of four years; however, we note that several other articles in the U. S. National report to IUGG for the Solar Planetary Relationships (SPR) section discuss selected aspects of wave and instability phenomena. Specifically, numerical simulations are discussed by Ashour‐Abdalla [1987], phenomena in the magnetopause and bow shock by Elphic [1987], magnetospheric tail pheomena by Huang [1987], electric fields and currents by Mauk [1987], auroral phenomena by Gorney [1987], and planetary (Jupiter, Saturn, and Uranus) phenomena are covered by Connerney [1987]. We have attempted to avoid extensive overlap between these reviews and the present report.
Radio Occultation Measurements of The Mars Atmosphere with Mariners 6 and 7
Authors: Hogan Joseph S. , Stewart Richard W. , Rasool S. I. 
Published: February 2008

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, respectively.
Stable Solutions of Ionospheric Fields in the Propagation of ELF and VLF Waves
Authors: Galejs Janis 
Published: February 2008

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 the F region and to compute propagation parameters of ELF and VLF waves.The propagation parameters of ELF fields are dependent on the altitude of the F region 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 an F region. 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.
The magnetic ion‐mass spectrometer on Atmosphere Explorer
Authors: Hoffman J. H. , Hanson W. B. , Lippincott C. R. , Ferguson E. E. 
Published: February 2008

The magnetic ion‐mass spectrometer is designed to measure the abundances of the ambient positive ions in the ionosphere. It will be calibrated in flight against the retarding‐potential analyzer and the cylindrical electrostatic probe to give absolute concentration data for the ion species detected. These parameters can be measured to approximately ±10% in well‐behaved regions where concentrations are above 103 cm−3. However, in highly structured polar regions, some degradation in accuracy may be expected.Three mass ranges, covered simultaneously by the scan of the instrument, 1 to 4, 4 to 16, and 16 to 64 amu, permit measurement of the entire mass range, 1 to 64 amu, in 1 sec in the main (peaks) mode. An alternate mode, analog‐long, will extend the mass range to 90 amu with a 9‐sec period. Capability is provided to lock onto any set of mass numbers in the ratio 1:4:16 to give very high spatial resolution, e.g., 500, 250, and 125 m in the low‐, mid‐, and high‐mass ranges, respectively. This mode will be most useful in the despun satellite orientation to provide fine‐structure data on ion concentrations. In the spinning mode the phase shifts between roll modulation maxima of heavy and light ions determine the vertical component of the individual ion‐drift velocities. Values from a few km sec−1 to over 20 km sec−1 can be determined. Such data are applicable to the study of polar wind phenomena.
The impedance of a dipole antenna in the ionosphere: 1. Experimental study
Authors: Vernet N. , Manning R. , Steinberg J. L. 
Published: February 2008

The impedance of a short electric dipole antenna has been measured from rockets in the ionosphere. The EIDI I experiment was launched in conditions where the plasma was expected to be nearly isotropic (operating frequencies 4.48 and 6.09 MHz, f0F2 ⋍ 9 MHz, fH ⋍ 1 MHz). It was designed to detect and measure or to eliminate most of the unwanted effects which complicated the data reduction of previous experiments: outgassing, telemetry radiation, etc. The number of parameters measured simultaneously on board (impedances with variable bias and RF excitation level, resonance frequencies, Te, dc current drawn by the antennas, vehicle potential) and from the ground or an overhead satellite was large enough to provide numerous cross checks and to determine the sheath dimensions.The impedance is very weakly spin‐modulated over most of the flight; the collision frequency is very low (v/ω ⋍ 10−5) unlike some of the previous experiments where collision losses were dominant. The measured values of the impedance are given as a function of X=f2p/f2 where the other parameters are known.
Is extension in Death Valley accommodated by thinning of the mantle lithosphere beneath the Sierra Nevada, California?
Authors: Jones Craig H. 
Published: February 2008

While relatively rapid and large‐scale extension occurred in the Death Valley region of California during Neogene time, little or no shallow extension occurred in the adjacent Sierra Nevada. This contrast in tectonic history has often been extrapolated to include the entire lithosphere, but geophysical and geologic observations indicate that more extension of the mantle lithosphere has occurred under the Sierra than under the Death Valley region. Upper mantle seismic velocities observed beneath the High Sierra are lower than those observed in other regions with comparable surface heat flow. This discrepancy could be resolved if the mantle lithosphere beneath the High Sierra had become warmer, presumably by tectonic thinning, in the last 10 m.y. Upper mantle seismic velocities, averaged topography, and Bouguer gravity anomalies all are consistent with the presence of thinner mantle lithosphere beneath the High Sierra than beneath the California portion of the Basin and Range Province to the east. This suggests that extension of the crust near Death Valley might be accommodated at a deeper level by thinning of the mantle lithosphere beneath the Sierra Nevada.The extension in the crust of the California Basin and Range Province and the thinning of the mantle lithosphere under the High Sierra appear to share the same bounds in time and space. The uplift of the High Sierra occurred over the past 9 m.y., which coincides with most of the extension that occurred in the California Basin and Range Province. Because the orientation of extension in the California Basin and Range Province is inferred to be approximately N60°W from geologic, geodetic, and in situ stress measurements, the northern and southern edges of the Death Valley extensional subprovince may extend N60°W from the inferred northern and southern limits of west dipping low‐angle normal faults of the Death Valley region. Pronounced changes in the averaged topography and Bouguer gravity anomaly across these two bounds both in the Basin and Range Province and in the Sierra Nevada support a connection between the tectonics of both regions. The geomorphic history of the southern Sierra suggests an up‐to‐the‐north warp of the Sierra across this southern bound during latest Cenozoic time. Hence extension near Death Valley may be localized in the crust and may be laterally connected to thinning of the mantle lithosphere beneath the Sierra Nevada. This geometry requires.
The magnetic observatories of the United States Coast and Geodetic Survey in operation on July 1, 1902
Authors: Bauer L. A. , Fleming J. A. 
Published: February 2008

I. SELECTION OF SITES OF THE MAGNETIC OBSERVATORIES.[Abstract].1The United States Coast and Geodetic Survey has in operation, in conformity with the plan of the magnetic survey of the United States and countries under its jurisdiction, outlined in Appendix 10, Report of the Superintendent of the Coast and Geodetic Survey for 1899,2 four magnetic observatories at which the manifold variations of the Earth's magnetism are being continuously recorded by photographic means. These continuous records, besides serving other useful purposes, are utilized in referring the values of the magnetic elements, obtained at various stations and at various times by the field parties engaged in the magnetic survey, to a common time.
Solar magnetism
Authors: Humphreys W. J. 
Published: February 2008

The recent study of Sun‐spots by Hale1 and his coworkers at the Carnegie Solar Observatory on Mount Wilson has led to important discoveries, of which probably the most fundamental are:(a) That the spots are cooler2 than the surrounding regions;(b) That they are centers of violent cyclones;(c) That they are accompanied by magnetic fields of great intensity.Many numerical details and other discoveries are to be expected from this Observatory at any time, but, accepting the above conditions as definitely proved to exist, the author begs to submit the following discussion of them.
On time scalings of magnetograms
Authors: Faris R. L. 
Published: February 2008

From some of the recent discussion2 that has appeared in reference to the accuracy of the time scalings of magnetograms (photomagnetic records) in connection with the study of the non‐simultaneity of abruptly beginning magnetic storms it would seem helpful to a clearer understanding of the subject to state specifically the method of time scalings that has obtained in reducing the results of the Coast and Geodetic Survey magnetic observatories.The five magnetic observatories of the Coast and Geodetic Survey are all equipped with a complete set of Eschenhagen type of variometers3 (Cheltenham having also an Adie magnetograph) and the photographic recording apparatus is so arranged that a time interval of one hour on the magnetograms is approximately twenty millimeters in length, thus making one millimeter correspond to a three minute time interval. The beginning of each hour is recorded on the base lines of the magnetogram by the light from the fixed mirrors of the variometers being interrupted, for a short interval of time, by small automatic shutters in the recording apparatus. The magnetic traces as well as the base‐lines are mechanically interrupted (by the observer) at least once each day, usually about 8 o'clock every morning. The time of this interruption, or break in the curves and base‐lines, is recorded. The error of the driving clock of the recording apparatus is then known from these daily comparisons with the standard observatory chronometer, the error of the latter on local mean time is known certainly to one‐tenth of a minute of time from observations made for the purpose about once a week or oftener if found necessary. There are five points on each magnetogram of about 24 hours' length, where time comparisons are made with the standard observatory chronometer, all five of which are recorded on the base lines, and three of which are recorded on the magnetic curves themselves, viz: at the beginning of the twenty‐four hour record (when the new photo‐sheet is put on), usually about 4:10 p.m., then another time comparison at the 5:00 p.m. hour break; the third reading is made about 8:00 a.m. the following morning (when the interruption of the magnetic trace is made as above mentioned) ; the fourth comparison of the time is made at the 4:00 p.m. time break, and finally a reading of the time is made at the close of the twenty‐four hour record when the photographic sheet is removed from the drum of the recording apparatus. As soon as the magnetogram is taken from the recording apparatus it is marked with distance marks (small holes are pricked through from the back of the trace at a known distance apart, by two small metal points fixed in a small wooden beam, like a beam compass), so that on the finished record, after it has been developed and fixed, the correction for shrinkage of the traces can be made if necessary, in scaling the ordinates when making the numerical tabulations.
The atmospheric potential gradient, and a theory as to the cause of its connection with other phenomena in atmospheric electricity, together with certain conclusions as to the expression for the electric force between two parallel charged plates
Authors: Swann W. F. G. 
Published: February 2008

The primary purpose of the following paper is to show that the theory of conduction of electricity in gases, combined with the assumption of an atmospheric potential gradient of such a sign that the potential increases with the height, leads us to expect:1(1) That the ratio of the number of positive ions per c. c. at the Earth's surface, to the number of negative ions shall be greater than unity.