Showing papers on "Solar eclipse published in 1970"
228 citations
TL;DR: In a solar eclipse, the moon shields a limited region of the earth's atmosphere from the heating effect of the solar radiation as discussed by the authors, causing the neutral gas to emit internal gravity waves that form a bow wave about the shadow region.
Abstract: In a solar eclipse, the moon shields a limited region of the earth's atmosphere from the heating effect of the solar radiation. This shadow travels through the earth's lower atmosphere at supersonic velocity, causing the neutral gas to emit internal gravity waves that form a bow wave about the shadow region. Tentative estimates of the amplitude of this wave indicate that it will be detectable well outside the area where the eclipse can be observed directly.
134 citations
92 citations
TL;DR: Flash spectra of the total solar eclipse throughout all its phases have been obtained in the extreme ultraviolet for the first time.
Abstract: Flash spectra of the total solar eclipse throughout all its phases have been obtained in the extreme ultraviolet for the first time.
31 citations
TL;DR: In this paper, measurements of Faraday rotation and differential absorption on frequencies 2.2, 3.9 and 7.8 MHz have been used to determine the height distribution of collision frequency and electron concentration during the annular solar eclipse of May 20, 1966 and on a comparison day.
17 citations
TL;DR: The outer corona brightness and polarization during the total solar eclipse from satellite photographs from satellite images were analyzed in this article, showing that the corona brightens and polarizes during the eclipse.
Abstract: Outer corona brightness and polarization during total solar eclipse from satellite photographs
16 citations
TL;DR: Ionospheric Lyman alpha intensities and electron and positive ion densities during solar eclipse of 20 May 1966, discussing recombination model as mentioned in this paper, discussed recombination models.
14 citations
TL;DR: Changes in the vertical distributions of copepods, meroplankton and scattering layer and bioluminescent organisms were attributed to the exogenous light effects of the eclipse.
Abstract: THE solar eclipse of March 7, 1970, provided an opportunity to examine the reactions of zooplankton. to rapid changes in light intensities. Diurnal changes in the vertical distribution of zooplankton are recognized behavioural phenomena1,2. Light is considered to be the principal stimulus to vertical movement in planktonic crustaceans3,4. The basic pattern of diurnal distribution is a rise to the surface in late afternoon in response to decreasing light intensity, followed by a sinking in the absence of a light gradient at night; as light increases at dawn the zooplankton moves upward to the source of light change, and then downward away from the increasing intensity of daylight2. The general pattern of movement can vary, however, under the influence of various exogenous and endogenous conditions5. Observations of the responses of zooplankton to solar eclipses are limited to the studies of Petipa6, Skud7 and Backus, Clark and Wing8; changes in the vertical distributions of copepods, meroplankton and scattering layer and bioluminescent organisms were attributed to the exogenous light effects of the eclipse.
13 citations
01 Jan 1970
TL;DR: Underwood and Muney as discussed by the authors used a series of small sounding rocket experiments to measure the ionospheric D-region electron density profile during successive stages of the eclipse, and they concluded that 2-8 A X-rays were not the dominant source of Dregion ionization below approximately 80 km.
Abstract: Rocket (Underwood and Muney, 1967) and satellite observations of 2–8A X-ray emissions indicate that the solar eclipse of May 20, 1966 occurred during a period in which the Sun was moderately active. The Goddard Space Flight Center conducted a series of small sounding rocket experiments to measure the ionospheric D-region electron density profile during successive stages of the eclipse. Compared to the uneclipsed profile, an order of magnitude reduction is observed in the D-region profile obtained near totality. From the electron density measurements together with the X-ray spectral data of Underwood and Muney it is concluded that on May 20, 1966, 2–8 A X-rays were not the dominant source of D-region ionization below approximately 80 km.
13 citations
TL;DR: The partial reflection technique has been used to measure the time variations of D -region electron densities at 74 and 80 km throughout the solar eclipse of 20 May 1966 as mentioned in this paper, and the average diurnal variation of the electron density has also been derived from measurements over a period of about two weeks prior to the eclipse.
13 citations
TL;DR: Radio observations of the solar eclipse of 7 March 1970 were made at several observatories in a cooperative effort, covering a wavelength range of 2.1 mm to 2 cm, and an analysis of the radio observations is given.
Abstract: : Radio observations of the solar eclipse of 7 March 1970 were made at several observatories in a cooperative effort, covering a wavelength range of 2.1 mm to 2 cm. An analysis of the radio observations is given. (Author)
TL;DR: In this paper, an estimate of the production of ionization in the D-region by Lyman-α acting on nitric oxide was made, and the molecular oxygen density from 70 to 85 km was deduced from the absorption of Lymanα in the atmosphere and the height variation of electron collision frequency has been calculated from the air pressure.
TL;DR: Coronal observations from Aerobee 150 rocket after total solar eclipse of 7 March 1970 in Mexico, combining coronagraph flight record with ground photography.
Abstract: Coronal observations from Aerobee 150 rocket after total solar eclipse of 7 March 1970 in Mexico, combining coronagraph flight record with ground photography
TL;DR: Observations of this eclipse seem to support the model: “there is a general similarity between the two drawings” (prediction and observation) and a sketch of the observations “agrees well with the prediction; had Schatten drawn his streamers more nearly radial, the agreement would have been almost perfect”.
Abstract: ON March 3, I made a prediction of the coronal structure of the March 7, 1970, eclipse of the Sun. The model employed is similar to that used for the prediction of the coronal structure at the eclipse of September 22, 1968, and details of the method are described in ref. 1. Observations of this eclipse seem to support2 the model: “there is a general similarity between the two drawings” (prediction and observation)3, and a sketch of the observations “agrees well with the prediction; had Schatten drawn his streamers more nearly radial, the agreement would have been almost perfect”4.
TL;DR: A maximum 86% obscuration of the solar disk was observed at about 1007 local time (0307 GMT) in Bangkok, Thailand, which was approximately 290 km from the center of the eclipse path as discussed by the authors.
Abstract: Vertical-incidence (VI) ionograms, magnetograms, and relative VI signal-amplitude (7-MHz) data were obtained in Bangkok, Thailand, during the annular solar eclipse on 23 November 1965. A maximum of 86% obscuration of the solar disk was observed at about 1007 local time (0307 GMT) in Bangkok, which was approximately 290 km from the center of the eclipse path. Marked changes in F2-layer virtual height and considerable stratification of the F layer, including formation of an F1.5 layer, were observed. Magnetograms indicate a large (approximately 25%) diminution in ionospheric current relative to normal solar daily (Sq) variations.
TL;DR: In this article, the authors measured the residual flux at the time of the greatest magnitude as a proportion of the total solar flux at 30 and 16 GHz using the Crawford Hill Sun tracker.
Abstract: ON March 7, 1970, the solar eclipse was observed at 30 and 16 GHz using the Crawford Hill Sun tracker1. At Crawford Hill the eclipse was partial with greatest magnitude of 0.964. The measurement consisted of an accurate determination of the residual flux at the time of greatest magnitude as a proportion of the total solar flux. From these data, the size of the radio Sun at 30 and 16 GHz is determined.
TL;DR: The 1966 Douglas Solar Eclipse Expedition obtained photographic records of the intensity and polarization of the solar corona on November 12, from a site at Chiguata, Peru as mentioned in this paper.
Abstract: The 1966 Douglas Solar Eclipse Expedition obtained photographic records of the intensity and polarization of the solar corona on November 12, from a site at Chiguata, Peru. The present paper amplifies a preliminary account in a special publication (Proceedings: Eclipse Symposium, Sao Jose dos Campos, February 5–9, 1968, in press). Here we shall give a more complete description of the equipment, its calibration, methods of reduction, and the results obtained. We compare the observed intensities and polarizations with those predicted by van de Hulst and point out structure indicated by the polarization data. These observations reveal the existence of complicated structures with intensities and polarizations both higher and lower than required by the van de Hulst model. In general high intensities correlate with high polarizations and low intensities with low polarization. However, some instances occur where seemingly normal intensities are associated with lower polarizations and low intensities with high polarizations. We account for these discrepancies in terms of electron concentrations along the line of sight, which do not occur in the simplified model corona. Further, we suggest that the existence of structure, such as streamers, rays, and so on, in the outer corona indicates that the current models tend to underestimate the importance of the K corona in this region.
TL;DR: One of the Ugaritic texts of the Second Millennium BC describes a total eclipse of the Sun and the date is established as 1375 BC, May 3.
Abstract: One of the Ugaritic texts of the Second Millennium BC describes a total eclipse of the Sun. The date is established as 1375 BC, May 3.
TL;DR: Solar UV flash spectrum by spectroheliographs flown aboard Aerobee 170 mission during total solar eclipse is pictured.
Abstract: Solar UV flash spectrum by spectroheliographs flown aboard Aerobee 170 mission during total solar eclipse
01 Dec 1970
TL;DR: In this article, an experiment to study the influence of a solar eclipse on the earth's lower atmosphere was conducted at Eglin Air Force Base, Florida, where a total solar eclipse occurred on 7 March 1970.
Abstract: : An experiment to study the influence of a solar eclipse on the earth's lower atmosphere was conducted at Eglin Air Force Base, Florida, where a solar eclipse occurred on 7 March 1970. Three temperature-ozonesondes and eight Arcasondes were deployed into the upper stratosphere and lower mesosphere at times prior to, during, and after the total eclipse. In addition, two electrochemical ozonesondes were flown on balloons on 5 and 6 March. Resulting temperature, wind and ozone data are presented. No measurements were made during the totality. An increase in ozone was measured during and several hours after the partial eclipse. Higher temperatures and a perturbation in the zonal wind field were observed in the middle stratosphere during the partial eclipse.
TL;DR: In this article, transient solutions of time dependent continuity equation (TDE) were used to calculate electron concentrations in the equatorial F 2 layer during the solar eclipse, and the electron concentrations were calculated using the time-dependent continuity equation.
Abstract: Solar eclipse effects on equatorial F 2 layer by transient solutions of time dependent continuity equation, calculating electron concentrations
01 Jan 1970
TL;DR: A summary of ionospheric theory pertinent to solar eclipses, based on a paper presented at the Summer School on Ionosphere held at Athens in 1966, is given in this article.
Abstract: It is 14 years since the last international symposium on solar eclipses was held in London in 1955 (Beynon and Brown 1956). This interval of 14 years has represented the advent of the space age, and the results of this considerable period of enhanced activity on research on the earth’s environment provide most of the material for this paper. My task is made easier by the fact that a summary has recently been prepared (Rishbeth 1968) of ionospheric theory pertinent to solar eclipses, based on a paper presented at the Summer School on Ionosphere held at Athens in 1966.
01 Jan 1970
TL;DR: The annular solar eclipse over the North part of Africa and the East part of Europe on May 20, 1966, was observed by a number of ionosonds, located along or near the central eclipse path as mentioned in this paper.
Abstract: The annular solar eclipse over the North part of Africa and the East part of Europe on May 20, 1966, was observed by a number of ionosonds, located along or near the central eclipse path.
01 Apr 1970
TL;DR: In this article, positive ion composition measurements in the D and E regions were performed on three rocket flights during the 1966 solar eclipse program conducted at Cassino, Brazil and showed that the decay in the water cluster ions at totality was probably less than a factor of four in the vicinity of 80 km.
Abstract: : Positive ion composition measurements in the D and E regions were performed on three rocket flights during the 1966 solar eclipse program conducted at Cassino, Brazil. The E region results showed that, at totality, NO+ and O2+ decreased in density while the ratio NO+/O2 increased. Long-lived meteoric ions appeared to be unaffected during the short period of the eclipse. A submerged layer of meteoric ions became prominent at totality when the molecular ion densities were smallest and produced a sporadic E layer. The D region results indicated that the decay in the water cluster ions at totality was probably less than a factor of four in the vicinity of 80 km. This work represents part of a continuing Air Force program to study lower ionospheric processes which affect communications.
TL;DR: Electron density measurements by partial reflection and rocket techniques during 20 May 1966 solar eclipse, showing agreement below 82 km height as mentioned in this paper, showed that the density of the electron was lower than 82 km.