摘要:

This paper discusses the pre‐sunrise decrease in height of the reflection point noted in 150 kc/sec vertical incidence group height recordings. It is shown that the local time of this decrease has a pronounced seasonal variation. The total number of particles along the sun ray to the reflection point where the height decrease begins has been computed. This number is almost constant throughout the year, yielding a value of about 3.3×1020atmospheric particles.By considering the composition of the upper atmosphere, it is shown that the only constituent which might possibly be subject to the pre‐sunrise ionization is O2. The corresponding solar radiation should have λ>910Å. The value for the absorption coefficient of O2obtained from these considerations is KO2= (3.3 ± 2.1) × 10‐19 cm 2.It is shown that the pre‐sunrise ionization is not due to a pure scre

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00439

年代:1952

数据来源: WILEY

摘要:

Steady velocities of an air bubble moving along the axis of rotation of a glass cell filled with water were measured at two angles of tilt from a horizontal direction and at several rotational speeds. These velocities, many times smaller than Stokes' law would predict, can be explained by taking into consideration hydrodynamic forces which depend on density and the speed of rotation. An experimental determination of the law of resistance to the movement of a bubble in this rotating system leads to revised estimates of apparent surface electrical charge density inferred from measurements of electrical mobilities. These estimates, approximating 0.8 esu cm−2, are ten or more times larger than formerly reported. Furthermore, the surface charge density appears to be nearly independent of the bubble diameter. The electrification has been measured in a different manner with the same apparatus by establishing a static balance between the force of an electric field parallel to the axis of rotation and a component of the force of buoyancy. The charge carried by the bubble is not dependent upon its motion.The electrification of bubbles of air rising freely in water was measured also, and the magnitude of the apparent surface charge density has been found to be only about one‐third that obtained with the rotating system under similar chemical conditions. This discrepancy is believed to be due to a lack of sufficient time for the rising air bubbles to attain an equilibrium electrified state. The observed effect of CO2as a water impurity is to reduce the electrification of an air bubble, in agreement with the measurements of other investigat

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00459

年代:1952

数据来源: WILEY

摘要:

Analysis of data for Washington and Watheroo indicates differences in the relationship between ƒ°F2 and sunspot number for the current and preceding sunspot cycles. The sunspot number is therefore not entirely satisfactory as an index for ionospheric variations. Consequently, ionospheric data for the current cycle only should be used in preparing ionospheric radio propagation predictions whenever possibl

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00473

年代:1952

数据来源: WILEY

摘要:

A numerical solution is given for the problem of a long insulated wire carrying a uniform oscillating current over a stratified earth with a highly conducting lower layer. The resultant electrical field parallel to this wire is shown to be influenced to an appreciable extent by the presence of a conducting zone at a depth of 500 meters for a frequency of 500 cycles per second.

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00481

年代:1952

数据来源: WILEY

摘要:

The results of an oblique incidence pulse experiment at 300 kc, using a path length of 1,185 km over sea‐water, are presented. These consist of median time delays of sky wavevssurface wave for March, April, and May, 1951, together with pulse envelope photographs of typical pulse groups, continuous film recordings of surface‐ and sky‐wave pulses, a plot of sunrise transition times, and a discussion of the sunrise condi

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00487

年代:1952

数据来源: WILEY

摘要:

The concentrations of the various radioactive decay products of radium in the air have been determined by observing the beta activity (1) of pieces of filter paper through which air has been passed, and (2) of chemically separated isotopes obtained from such filter papers. The relative amounts of long‐lived and short‐lived products found indicate that, besides the radioactive decay of the substances, some other process which removes radioactive particles from the air is active. The mean life of the particles with respect to this removing process is found to be about 10 days. The hypothesis that this process is the capture of the radioactive particles by rain droplets (clouds) is consistent with measurements made of the radioactive content of rain‐water. On the other hand, the removal of the ionized radioactive particles by the electric field of the earth leads to a much smaller e

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00499

年代:1952

数据来源: WILEY

摘要:

A theoretical current system, similar to the models proposed by Birkeland and Alfvén as sources of geomagnetic disturbance, is analysed, and the magnetic field produced by it is compared with the observational data and the fields of other theoretical models. The results indicate that the Birkeland model, which has been rejected by Vestine and Chapman, and Alfvén's model are unsatis‐factory as sources of the daily variation (SD) of geomagnetic disturbance. Some general principles are developed for use in the field analysis of current syst

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00511

年代:1952

数据来源: WILEY

摘要:

This article seeks to develop a picture of the physical processes in space which are responsible for the existence of field phenomena, deriving certain relations between these phenomena outside the scope of the usual field theories.Field phenomena represent processes on such a fine scale that details are, in general, unobservable (except insofar as the quantum aspect is concerned). We can, therefore, only classify and determine netenergy differences, but this is all that is needed to account for field phenomena at the ordinary scale of magnitude.I have discussed the derivation and interpretation of the electro‐magnetic field equations in published articles (American Journal of Physics, 18, 509, Nov. 1950; also Journal of the Western Society of Engineers, 53, 87, June 1948). The present article extends the same basic structure to include gravitation, and indicates a simple relationship between gravitation and electromagnetis

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00527

年代:1952

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00531

年代:1952

数据来源: WILEY

ISSN:0148-0227    

DOI:10.1029/JZ057i004p00534-01

年代:1952

数据来源: WILEY