摘要:

Observation of the motion of trails produced by ejecting sodium vapor from rockets has allowed determination of some upper atmospheric winds. Simultaneous three‐site photography was used to determine the position of the trail over a period of several minutes. As the result of three rocket flights, twilight wind measurements have been made over the altitude region 77 to 200 k

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00587

年代:1959

数据来源: WILEY

摘要:

A study of the times of three sudden commencements, recorded on August 3, September 21, and November 6, 1957, respectively, at ten widely‐separated magnetic observatories, indicates that when main and preliminary impulses are both recorded at one place (as in the typical SC*) they really begin approximately simultaneously. Therefore, it would appear that in nontropical regions the rate of growth of the so‐called preliminary impulse is usually greater than that of the main impulse, so that the latter is obscured until the former begins to decay.Differences around the earth between recorded times of the first impulse, whether the sudden commencement is an SC or SC* type, are only a few seconds, and the evidence suggests that the position of the sun controls the hemisphere in which the sudden commencement first occurs. This finding is interpreted in terms of the Singer shock‐wave theory to mean that, as would be expected, the shock wave enters the auroral zone nearest the sun first and produces the sudden commencement a few seconds earlier in that hemisphere. At the equinox the sudden commencement times are roughly symmetrically distributed with respect to the geomagnetic eq

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00593

年代:1959

数据来源: WILEY

摘要:

Balloon observations were made during the auroral storm of February 10–11, 1958, at Minneapolis. Strong x‐ray bursts in two groups were detected. The groups appeared coincident with two large magnetic bays, with strong radio noise absorption, and with the passage across the zenith of a very large amount of auroral luminosity. From the x‐ray intensity and measured energies, an electron current of 0.6×106electrons/cm2/sec was present. These electrons ionizing the upper D layer accounted for the increased cosmic noise absorption. The X‐rays themselves carried 1000 times less energy than the electrons and could not provide sufficient ionization for the observed radio absorption. Visual auroral forms during this storm are reported to have lower borders at the 200 to 300 km level. There is thus a difficulty in bringing the electrons to the D layer without an accompanying visible aurora. A cosmic‐ray decrease accompanied the storm and was observed to be from 4 to 6 per cent at sea level, 21 per cent in the balloon altitude ionization, and 15 per cent in total energy influx at 55° geomagnetic latitude. Compared with the great intensity of the magnetic and auroral phenomena in this storm, the cosmic‐ray modulation was not except

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00597

年代:1959

数据来源: WILEY

摘要:

Published photometric observations of several OH bands are analyzed with the aid of available transition probabilities. The rate of excitation of the vibrational levels with υ≤9 by the excitation mechanism seems to be nearly independent of υ. The relative populations of the vibrational levels are computed, and the predicted absolute intensities of all the OH bands are gi

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00611

年代:1959

数据来源: WILEY

摘要:

The scientific results obtained from rocket and satellite observations have been studied in order to determine the physical properties of the atmosphere at high altitudes. A preliminary model atmosphere is presented for the region between 100 and 800 km. The paper contains numerical tables of density, pressure, and scale height as functions of altitude.Due to solar effects these physical parameters may vary from day to night and from latitude to latitude. However, preliminary studies have indicated that average densities and pressures might vary by at most a factor of two, the variations being larger at high than at medium latitudes. Densities presented by Russian scientists, which were also obtained from rocket and satellite data, agree with the model density presented here reasonably well. The densities derived by American and Russian scientists from satellite observations agree within less than a factor of two. The densities derived from rocket data are lower than the ones derived from satellite data for the same altitude. The maximum difference between the densities derived byMichnevich[1958] from rocket data and the average densities presented here occur around 150 km, where the values differ by a factor of 3.8; above and below these altitudes the differences are much less. It is estimated that these differences then are within the limits of the variations to be expected and also within the limits of the uncertainties of the experimental data available at present.

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00615

年代:1959

数据来源: WILEY

摘要:

Cosmic‐ray intensity data have been studied in Japan, and it has been found, that passages of cold fronts do not produce a pronounced variation in cosmic‐ray intensities. Warm fronts produce a gradual but pronounced decrease. Further evidence from the decrease in neutron counts accompanied by little change in ionization chamber records substantiates the conclusion that the variations are due to liquid‐water content of the atmosphere. Estimates of as much as 50 to 70 mm of liquid water in the atmosphere are supported by records of tremendous rainfall during the passages of typ

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00625

年代:1959

数据来源: WILEY

摘要:

The recent pronounced anomalous warming of surface waters of the eastern North Pacific is related to prevailing abnormalities in the overlying atmospheric circulation. The gross features of the abnormalities in water temperature patterns during the cold season appear to be caused by abnormal wind components. The data suggest that a preponderant surface drift of water masses from warmer (or colder) sources is induced, and this may be augmented by divergence and upwelling factors. The summer surface‐water temperature patterns suggest, in addition to surface advection, the possibility of heating through enhanced insolation combined with light wind.An attempt is made to ascribe long‐period continuity to the atmospheric mean seasonal circulations from summer 1957 through spring 1958 and to hypothesize that this continuity is the result of a certain interplay (involving feedback) between ocean and atmosphere against the slowly changing climatological backgro

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00631

年代:1959

数据来源: WILEY

摘要:

The deficiencies of various methods used to date for mapping the geographical variation of geophysical quantities are discussed. A method for constructing a practical equal‐area grid for use in such work is illustrated. It can be constructed for any scale or map projection and can also be used hemispherically. Its advantages over other methods are discussed. It is suggested that, in lieu of an equal‐area grid, it is better to use the raw frequencies inndegree squares than to adjust them by proportionality factors designed to equate the size of the squares to that of the equal‐area

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00647

年代:1959

数据来源: WILEY

摘要:

The melting point of iron has been determined to 96,000 atmospheres, and the temperature for the α‐γ transition to 76,000 atmospheres. Simon's fusion equation,P/a= (T/T0)e‐ 1, fits the experimental melting points witha= 75,000 atm andc= 8. Extrapolation of the melting points to 1.4×106atm, the pressure at the boundary of the earth's core, gives 2340±200°C. The temperature for the α‐γ transition decreased about 200°C

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00653

年代:1959

数据来源: WILEY

摘要:

All real materials have a finite thermal conductivity. This means that stress waves propagating through any physically real solid suffer energy losses due to heat conduction. The equations of motion and of temperature for an elastic solid with a finite thermal conductivity are derived with the aid of the irreversible form of the second law of thermodynamics. Their solution for frequencies of physical interest shows that the attenuation coefficient of a stress wave traveling in such a thermoelastic solid is proportional to the second power of the frequency.

ISSN:0148-0227    

DOI:10.1029/JZ064i006p00661

年代:1959

数据来源: WILEY