摘要:

Observations of cosmic radio‐frequency radiation on frequencies of 2130 kc/sec, 1435 kc/sec, 900 kc/sec, and 520 kc/sec have been made, using a method of recording which effectively reduces interference from atmospherics. At these frequencies, the intensity of the radiation is approximately 10−19watt per square metre per cycle per second per steradian. The ionospheric effects associated with observations near the critical frequency are discus

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00001

年代:1956

数据来源: WILEY

摘要:

The earth's external magnetic field, extending far beyond the ionosphere, is at present inaccessible to direct observation. However, the measurement of the nucleonic component longitude and latitude effects in the region of the geomagnetic equator now offers the possibility for determining the coordinates of an equivalent geomagnetic dipole which represents this external field without encountering the problems that have heretofore beset the use of meson intensity observations for this purpose. The method of measurement and the theory relating the cosmic‐ray intensity changes to the geomagnetic coordinates are outlined for deriving the two angles which determine the orientation of the dipole and the three coordinates giving the position of the magnetic center with respect to the center of the eart

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00011

年代:1956

数据来源: WILEY

摘要:

During a period of five years, impulses of atmospherics have been recorded on the following frequency ranges: Range I, about 10 to 50 kc; range II, about 4 to 12 kc. Only such impulses are counted and recorded the amplitudes of which exceed the relatively high threshold value of the amplifier.Considering the monthly means of the impulse sum per hour, we note that each of these five years shows two maxima. The first maximum, appearing during the summer months (May to August), can be explained easily by the frequency of thunderstorms occurring in central Europe in summer. The second one, however, which appears in winter, is strange.An exact analysis of the large‐scale weather processes results in the following: In the fall, the thunderstorm frequency in central Europe and in the Mediterranean regions is lowered because of large anticyclones (Azores high). During the winter months, violent invasions of polar air‐masses into the Mediterranean basin take place. Thus, moist labile gradients are formed over the relatively warm sea‐water, which give rise to renewed thunderstorms. These large‐scale changes of air‐masses are the reason for the observed winte

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00023

年代:1956

数据来源: WILEY

摘要:

In order to evaluate the possible role of radioactive particles from an atomic cloud as condensation nuclei, an analysis has been made to determine their degree of ionization. Individual radioactive particles become ionized due toβemission, and an estimate of the half‐life of these ions has been made for various times in the life history of an atomic cloud. It is concluded that while there is a transient charge on these particles, its half‐life is small compared to the disintegration rate, with the result that for all practical purposes radioactive particles in the free air are not necessarily preferred condensation nu

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00027

年代:1956

数据来源: WILEY

摘要:

Simultaneous observations of times of occurrence of whistlers were made at Seattle, Washington, and Stanford, California, two hours every week from October 1951 to October 1952. Times were measured to an accuracy of about ±1 second. The objective was to determine the percentage of whistlers received at either station which were coincident at both.A total of 318 whistlers was received at Stanford and 283 at Seattle during simultaneous observations. The occurrence rate of whistlers (during a two‐hour period) varied from 0 to roughly 55 per hour at Stanford and from 0 to 70 per hour at Seattle. The correlation between the occurrence rates was poor.The number of true coincidences was found by subtracting the number of chance coincidences from the number of total coincidences. A method for computing the number of chance coincidences from a knowledge of the time intervals between whistlers at the one station was derived. The analysis showed that approximately 22 per cent were observed simultaneously at both stations.This result is examined in relation to possible theories of whistler origin and propagation, and is shown to support the Storey‐Eckersley th

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00035

年代:1956

数据来源: WILEY

摘要:

The method and analysis of the rocket‐grenade experiment are briefly described. The 59 values of temperatures and of wind speeds and directions between 30 and 80 km obtained during 12 Aerobee rocket firings are summarized. The mean temperature distribution has a maximum of about 270°K at 50 km, with a lapse rate of about 2.5°/km above the peak. The winds are strong and from the west during the winter months (October through February); less strong and from the east during the summer months (April through August); and are comparatively weak and predominantly from the north during the fall (September). The maximum wind speed measured was a value of 104 m/sec at 55 km during a winter firing.The average probable error for the temperature data is ±5°C; the average errors in wind speed and direction are ±10 m/sec and ±18°, resp

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00045

年代:1956

数据来源: WILEY

摘要:

Precise aeromagnetic measurements of total magnetic intensity permit the construction of isomagnetic charts which are mutually consistent in the horizontal and vertical components of the geomagnetic fields. Equations incorporating this new result are provided.

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00057

年代:1956

数据来源: WILEY

摘要:

During March 1951, a series of visual auroral observations were made simultaneously with ionospheric soundings at Barrow, Alaska (71° north, 156° west). Aurorae were visible during 82 per cent of the 379 observations, made at least every 15 minutes during the dark hours of 10 successive clear nights. Three nights are described in detail. Statistical results include (1) a strong tendency for sporadic‐E(Es) echoes at frequencies ≥ 7 Mc to be recorded when aurora was near the zenith; (2) a direct relationship between brightness of (inactive) aurora and the top frequency ofEsechoes; (3) evidence for the correspondence of (oblique)Esecho ranges with estimated slant ranges of visible auroral forms. The observations lend support to the view that ionization in the immediate vicinity of visible auroral forms gives rise to ionospheric‐type reflections at high freq

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00059

年代:1956

数据来源: WILEY

摘要:

The effect of thermal conductivity in controlling the temperature distribution of the high atmosphere is considered. The energy absorbed in theFregion is conducted downward into a denser region of the atmosphere, where it is dissipated by infrared emission. The calculations indicate that the atmosphere is isothermal above about 250 km, and that between 100 and 200 km there is a very strong positive temperature gradient. The temperature in the isothermal region is assumed to be 1100°K, in order to provide enough atmosphere near 300 km to support anF2 region. The low temperature at 80 km is due primarily to the lack of absorbed energy there rather than to the presence of a strongly emitting layer at that level

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00071

年代:1956

数据来源: WILEY

摘要:

Data were obtained from four balloon‐launched Deacon rockets during the summers of 1953 and 1954, without the aid of groundbased trajectory measurements. The atmospheric density profile in the 25‐ to 45‐km region was found within the experimental error to be the same as the Rocket Panel, White Sands values. The measured atmospheric pressure and the computed temperature for the flights at 62° and 74° north were found to be up to 30 percent higher in the 30‐ to 45‐km region, but approximately equal to the White Sands values at 70 km. At 74° north, a high lapse‐rate is indicated within the regi

ISSN:0148-0227    

DOI:10.1029/JZ061i001p00077

年代:1956

数据来源: WILEY