Showing papers on "Solar eclipse published in 1972"
TL;DR: In this article, positive ion composition measurements in the D- and lower E-regions were performed on three rocket flights during the November 1966 solar eclipse program conducted at Cassino, Brazil.
95 citations
TL;DR: A Fourier analysis showed a primary wave with a period of 89 min and an amplitude of 250 μb with small peaks with periods of 57, 51, 45, 38, 20.3, 18.2, 15.7 and 12.3 min this article.
Abstract: Air pressure and temperature measurements were made during the 7 March 1970 solar eclipse. A Fourier analysis showed a primary wave with a period of 89 min and an amplitude of 250 μb. Smaller peaks were found with periods of 57, 51, 45, 38, 20.3, 18.2, 15.7 and 12.3 min. The primary wave agreed reasonably well in magnitude and phase with five earlier eclipse measurements dating back as far as 1887. The temperature decreased 3C with a minimum slightly after totality. This occurred under a thick cloud blanket.
77 citations
TL;DR: In this paper, observations of very low frequency radio signals were made in Newfoundland during the solar eclipse of 7 March 1970, where the ionospheric reflector height varied from 69 km at the start of the eclipse to 76 km at maximum totality.
38 citations
TL;DR: In this paper, the solar eclipse of Mar. 7, 1970, with photometers sensitive to narrow bands of radiation at Lyman-alpha (1216 A) and at 2600 A included in the payloads of four Nike Apache rockets flown before and during the eclipse.
31 citations
TL;DR: The results of continuous measurements of electron temperatures, electron concentrations, and vertical plasma drift made at Jicamarca during the 1969 solar eclipse and of control measurements made on Sept. 13, 1969 were presented in this paper.
Abstract: Results of continuous measurements of electron temperatures, electron concentrations, and vertical plasma drift made at Jicamarca during the Sept. 11, 1969, solar eclipse and of control measurements made on Sept. 13, 1969. Synthesis of the observed electron concentrations was made, using a model that solved the time-dependent electron-ion continuity equations. Ions O(-), NO(+), O2(+), and N2(+) were treated. Physical and chemical processes pertinent to the F region were considered in a realistic way. At noon, 300 km above Jicamarca, the values q = 290 per cu cm per sec for the O(+) production rate, beta = 1.94 x 0.0001 per sec for the loss coefficient, and H = 59 km for the atomic oxygen scale height were obtained. All large-scale features observed in the F2 region were synthesized by the model. This synthesis was not sensitive to a simultaneous 30% reduction of q and beta.
28 citations
TL;DR: Chimonas and Hines as mentioned in this paper pointed out that the Moon's shadow on the Earth's atmosphere during a solar eclipse constitutes a cooling region travelling at supersonic speed, and that it may therefore be expected to generate a bow wave with a magnitude of about 10−5 atmosphere at ground level and 10−1 of ambient pressure at 200 km altitude.
Abstract: Chimonas and Hines1 have pointed out that the Moon's shadow on the Earth's atmosphere during a solar eclipse constitutes a cooling region travelling at supersonic speed. It may therefore be expected to generate a bow wave with a magnitude of about 10−5 atmosphere at ground level and 10−1 of ambient pressure at 200 km altitude. Chimonas2 estimates the frequency of the bow wave to be very low, corresponding to a period of about 4 h.
26 citations
TL;DR: The effect of the total solar eclipse of 7 March 1970 on some oceanic Copepoda and Euphausiacea in the Gulf of Mexico was studied by taking 10min tows with Clarke-Bumpus nets on the days before, during, and after the eclipse as discussed by the authors.
Abstract: The effect of the total solar eclipse of 7 March 1970 on some oceanic Copepoda and Euphausiacea in the Gulf of Mexico was studied by taking 10-min tows with Clarke-Bumpus nets on the days before, during, and after the eclipse. Illumination was continuously recorded. Most organisms that responded to the eclipse did so by migrating to the surface during totality. The magnitude of this response appeared to exceed that to the decrease in light intensity at night.
23 citations
TL;DR: In this article, the occurrence of sporadic E ionization during the partial solar eclipse of 1955 over Haringhata is studied in the light of the present theory relating to internal gravity waves.
Abstract: Occurrence of sporadic E ionization during the partial solar eclipse of 1955 over Haringhata is studied in the light of the present theory relating to internal gravity waves. It is found that the variation of fEs indicates a periodicity that is inexplicable by the normal eclipse effect observed for regular ionospheric layers. From a critical study of the variation, tentative conclusion is drawn indicating that the enhancement of Es ionization during the solar eclipse over this station may be related to internal gravity waves generated in the atmosphere from the fast-moving cooling spot of the shadow region.
23 citations
TL;DR: In this paper, the Waldorf observatory for atmospheric electricity is described and data are presented in which strong perturbations are produced by the action of the eclipse. And it is shown that the diminution and subsequent restoration of eddy turbulence near the ground can produce effects of the type observed if adequate consideration is given to the existing electrical state of the atmosphere during the fully developed turbulence prior to the Eclipse.
18 citations
TL;DR: The amplitudes and phases (relative to a local high precision frequency standard) of WWV HF transmissions on 5, 10 and 15 MHz from Ft. Collins, Colorado, were recorded continuously during the period of the total solar eclipse on 7 March 1970.
17 citations
TL;DR: Differential photoelectron flux in the energy range of 3 to 50 eV has been measured in the lower ionosphere both during the March 7, 1970, solar eclipse and during a period 24 hours earlier as discussed by the authors.
Abstract: Differential photoelectron flux in the energy range of 3 to 50 eV has been measured in the lower ionosphere both during the March 7, 1970, solar eclipse and during a period 24 hours earlier. The two measurements were made with identical retarding potential analyzers carried on Nike-Apache rocket flights to a peak altitude of approximately 180 km. The differential electron flux spectrum within totality on the eclipse flight had the same shape but was a factor of 10 smaller in magnitude than that measured on the control day at altitudes between 120 and 180 km, an expected result for an eclipse function decreasing to 1/10 at totality. The differential flux spectrum measured in full sun has the same general energy dependence as that reported by Doering et al. (1970) but is larger by a factor of 2 to 10, depending on altitude.
TL;DR: In this article, it was found that the eclipse caused a maximum decrease in the electron number density by more than a factor of 10 below 80 km, but by only 3-5 above 85 km.
TL;DR: In this paper, the authors analyzed radio sounding data collected on 7 March 1970 with primary interest in detecting any traveling ionospheric disturbances generated by the solar eclipse of that day, as postulated by Chimonas and Hines.
TL;DR: In this article, the authors studied the solar eclipse of March 7 1970 in the thermosphere above Wallops Island, North Carolina, USA and showed that the ion chemistry in the atmosphere above the island was stable during the eclipse.
01 Jun 1972
TL;DR: In this paper, the authors investigated whether the observed variations in electric parameters are caused by near-ground processes (related to eddy diffusion) or by high-altitude processes and concluded that simple models are not sufficient to explain the sequence of variations seen in the data.
Abstract: Measurements of the electric field, the vertical current density, space charge and conductivity have been carried out at five ground stations and three series of free-air measurements during the 7 March 1970 solar eclipse in and near the totality zone. The problem whether the observed variations in electric parameters are caused by near-ground processes (related to eddy diffusion) or by highaltitude processes is not yet solved. It was possible, however, to offer a speculative explanation with the first assumption for the majority of the observations. The most important conclusion is the ecquisition of a better understanding of the requirements for measurements made for investigating solar eclipse effects. Also, it seems that simple models are not sufficient to explain the sequence of variations seen in the data.
TL;DR: In this paper, total electron content measurements obtained from polarization data of the ATS-3 satellite beacon on 137.35 MHz were observed at Ft. Monmouth N.J. during 6-9 March 1970, and the period of the content oscillations was found to be 18 ± 3 min.
TL;DR: The results of soundings with a series of five pitot probes launched in conjunction with the solar eclipse of Mar. 7, 1970 were reported in this paper. But the results were limited to a 42-min period and the remaining two soundings were made 24 hr before and after the eclipse.
TL;DR: In this article, the absolute skylight intensity and polarization were measured at 5577, 5780, 6100 and 6300 A using an interference filter photometer mounted in a jet aircraft flying at an altitude of 12.2 km during the total solar eclipse of 30 May 1965.
Journal Article•
TL;DR: In this paper, it is shown that the variations in the recorded atmospheric electric variables and in the spectral decay exponent are consistent with a strong diminution of turbulence near the ground as the Sun is obscured and the establishment of a thin layer above the ground in which a higher than normal density of small ions is produced by surface radioactivity.
TL;DR: In this paper, columnar electron content using geostationary satellite signals were made at several of our observatories throughout the U.S., during the 7 March 1970 solar eclipse, and the ionospheric response was simulated in a computer.
TL;DR: In this paper, the authors discuss the solar eclipse of 30 September 1131 b.c. and its effect on the history of the Middle East and present-day world, including the following:
Abstract: (1972). Joshua 10:12–14 and the Solar Eclipse of 30 September 1131 b.c. Palestine Exploration Quarterly: Vol. 104, No. 2, pp. 139-146.
TL;DR: In this article, the authors used a combination of a sharp cut filter and KODAK IV F film for the second contact of the Mexico eclipse on 7 March 1970, and the band width was 150 A. The intensity distribution of the solar outer layers obtained shows a steep decrease by a factor of 0.9 in logarithmic units around 2500 km.
Abstract: Direct images of the Sun were photographed in continuum emission centered at 6900 A by the jumping film method near the second contact of the Mexico eclipse on 7 March 1970. The band width was 150 A defined by a combination of a sharp cut filter and KODAK IV F film. The intensity distribution of the solar outer layers obtained shows a steep decrease by a factor of 0.9 in logarithmic units around 2500 km. This is interpreted as the boundary of the chromosphere and corona. Spicules observed at 3500 km are explained by log n e = 11.25 and T e ≈ 6000 K. Discussions are made in relation to the other observations and some chromosphere models.
01 Jan 1972
TL;DR: In this article, the authors investigated the response of the ionosphere and ionosphere to rapidly changing solar illumination at a low zenith angle during a solar eclipse at Wallops Island on 7 March 1970.
Abstract: flights to be resolved. The neutral temperature and N, concentration changed little but the electron temperature decreased by as much as 20 per cent in the lower P-region. The ion concentration decreased by about 30 per cent in the P-region and about 50 per cent in the E-region, with little change in relative ion composition. The electron cooling rates decreased by a factor of 6 in the lower P-region, approximately in proportion to the change in visible solar disc. A smaller than expected decrease in the cooling rate below 150 km between the two flights indicates a hardening of the solar spectrum and suggests a significant heat contribution from the solar corona near totality. The ion composition measurements were consistent with solutions of the ion continuity equations. A proper fit required a factor of three enhancement of the flux below 200 A, an amount also consistent with the electron heat balance analysis. Reactions involving the minor ions N+ and N2+ were found to be important for the ion chemistry of the major ions O,+ and NO+, especially at the time of eclipse. The negligible response of the neutral atmosphere to the eclipse is reasonable considering the long time constants for the conductive and convective transport processes and the local nature of the disturbance. THE OCCURRENCE of a solar eclipse at Wallops Island on 7 March 1970 presented a unique opportunity to investigate the response of the thermosphere and ionosphere to rapidly changing solar illumination at a low zenith angle. The response times of this region depend inherently upon the ion reaction rates, the electron, ion and neutral cooling rates, and perhaps on dynamic effects associated with the rapid changes occurring during the eclipse. To investigate these changes, two identical Thermosphere Probes, NASA 18.104 and 18.105, were launched southeastward from Wallops Island into the path of the approaching cone of totality. At the apogee altitude of 290 km, the percentage obscuration had reached 42 and 84 per cent, respectively. The two rockets were launched along essentially identical paths to permit the purely temporal, eclipse-induced changes to be separated from any spatial variations that might otherwise have been encountered. In this paper, the resulting measurements of ion composition, total ion concentration, Ni, molecular nitrogen concentration n(N,) and temperature, TNI, and electron
01 Jan 1972
TL;DR: In this article, a new magnetic model is developed and compared with previous models and the observed solar corona, which is able to simulate to high accuracy an isothermal corona.
Abstract: A new magnetic model is developed and compared with previous models and the observed solar corona. An attempt is made to more accurately compute the three-dimensional currents flowing in the solar corona. Physical reasons are given that require most of the large scale currents flowing in the solar corona to lie near thin sheets. The current sheets are not constrained into any particular geometry or symmetry as in the previous models of Altschuler and Newkirk (1969) and Schatten et al. (1969). A comparison with the axisymmetric, isothermal MHD solution of Pneuman and Kopp (1970) suggests that the model is able to simulate to high accuracy an isothermal corona. A comparison of the model with the May 30, 1965, solar eclipse and the November 12, 1966, solar eclipse shows the model is capable of computing many features including the polar plume orientations as well as radial and nonradial streamers in the solar corona.
TL;DR: In this paper, a comprehensive digital computer program is described which automatically processes precision digitized data from conventional rocketsondes and radars to produce accurately corrected temperatures and winds together with estimated uncertainties at each point.
Abstract: A comprehensive digital computer program is described which automatically processes precision digitized data from conventional rocketsondes and radars to produce accurately corrected temperatures and winds together with estimated uncertainties at each point. Underlying models for the systematic errors in the Arcasonde 1A temperature sensor and the radar-tracked parachute wind sensor, and for the uncertainty in corrected results are presented. Techniques used to automatically edit, synchronize and filter data are also given. Performance is illustrated by graphical output from the eight meteorological soundings in the rocket series conducted at Wallops Island, Va., during the Mar. 7, 1970 solar eclipse. An operational version (METROK) of the program is in use at NASA Wallops Station.
Journal Article•
01 Jan 1972
TL;DR: In this article, the lines of polarity reversal from H-alpha solar patrol photographs were used to map the same large-scale features found on Mt. Wilson magnetograms to improve predictions of coronal features during the next solar eclipse.
Abstract: Coronal and interplanetary magnetic fields computed from measurements of large-scale photospheric magnetic fields suffer from interruptions in day-to-day observations and the limitation of using only measurements made near the solar central meridian. Procedures were devised for inferring the lines of polarity reversal from H-alpha solar patrol photographs that map the same large-scale features found on Mt. Wilson magnetograms. These features may be monitored without interruption by combining observations from the global network of observatories associated with NOAA's Space Environment Services Center. The patterns of inferred magnetic fields may be followed accurately as far as 60 deg from central meridian. Such patterns will be used to improve predictions of coronal features during the next solar eclipse.
TL;DR: In this paper, a retarding potential analyzer on a Nike-Tomahawk rocket during the total solar eclipse over Wallops Island, Virginia, showed definite evidence for the existence of photoelectrons from the conjugate hemisphere.