Showing papers on "Solar eclipse published in 1983"
TL;DR: In this article, the maximum value of O density was found to be 7 x 1011 cm−3, with a fact or of two uncertainty, and to occur near 95 km.
18 citations
TL;DR: In this paper, the Dresden Codex contains a table of temporal intervals appropriate to the cyclic occurrence of solar eclipses for the late 8th-century A.D. span to which it refers.
Abstract: Work by earlier scholars has shown that the Dresden Codex contains a table of temporal intervals appropriate to the cyclic occurrence of solar eclipses. This paper demonstrates that if the Maya calendrical dates in the table are converted to the Gregorian calendar by using the so-called Modified Thompson 2 correlation constant, the table gives very accurate warnings of solar eclipses for the late-8th-century A.D. span to which it refers. During the approximately 33 years between November 10,755, and September 6, 788, all of teh 77 solar eclipses affecting the planet occurred within three days of dates appearing in the table. Although most of these eclipses did not affect the Maya area, the table itself provides a mechanism for recognizing and discounting irrelevant predictions. No visible solar eclipse of the late 8th century could have occurred without a very precise warning if the table were used in the fashion suggested here. It has often been assumed that the table was intended to be recycled or reuse...
17 citations
TL;DR: In this article, positive and negative ion concentrations and mobilities have been obtained from an analysis of Gerdien condenser measurements on rocket flights, A10.802-1 and A1O.
14 citations
TL;DR: In this article, electron density profiles and energetic particle fluxes are obtained based on data collected by two rockets launched from Red Lake, Ontario, respectively, at the beginning and end of totality during the solar eclipse of February 26, 1979.
12 citations
TL;DR: In this article, electrical conductivity and its constituent parameters, charge density and ion mobility, are presented for the solar eclipse rocket campaign conducted at Red Lake, Ontario, Canada, as indicated by the probe measurements.
10 citations
Journal Article•
9 citations
01 Oct 1983
7 citations
TL;DR: A model of the lower thermosphere has been developed to describe the D and E-regions of the ionosphere for this case with the model being guided by the measurements as mentioned in this paper.
7 citations
TL;DR: In this article, the authors show that the ratio of peak line intensity to square of the continuum intensity Eline/E 2 appears to be inversely corre- lated to the temperature.
Abstract: Fabry-Perot interferometfic observations in the green coronal line during the total eclipse of 1980 February 16, have yielded line-width temperatures up to 1.5 R over a wide range of position angles. Least square analysis of the data indicates a tentative temperature maximum near 1.2 R from the centre of the Sun. The ratio of peak line intensity to square of the continuum intensity Eline/E 2 appears to be inversely corre- lated to the temperature. Turbulent velocities calculated using this ratio and the observed line-width temperatures show a peak at ~ 10 km s -1 .
6 citations
TL;DR: In this article, the authors used the Kuiper Airborne Observatory observations of the solar limb during the total solar eclipse of 1981 July 31 to estimate the spectral lengths of the visible and infrared bands.
Abstract: First results are presented of observations of a lunar occultation of the solar limb made from the Kuiper Airborne Observatory in the 30 micrometr, 50 micrometer, 100 micrometer, and 200 micrometer continuum during the total solar eclipse of 1981 July 31. The solar limb was extended at the longer wavelengths up to 1000 km higher than predicted from smooth plane-parallel chromospheric models. Results at both second and third contact show the infrared limb extensions to be approximately 0".8, 1"5, 2".5 and 3".0 above the visible limb in the observed bands, respectively. A possible interpretation proposes chromospheric fine structure inhomogeneities of greater density than presently incorporated in models of the middle chromosphere.
6 citations
Journal Article•
TL;DR: Ce eclipse a pratiquement coincide avec le maximum du cycle solaire 23 as discussed by the authors, and on determine la structure de la couronne solaire en lumiere blanche and les associations avec les phenomenes photospheriques.
Abstract: Cette eclipse a pratiquement coincide avec le maximum du cycle solaire 23. On determine la structure de la couronne solaire en lumiere blanche et les associations avec les phenomenes photospheriques
TL;DR: In this article, the analysis of positive ion composition data obtained by AFGL for eclipse and post-eclipse conditions near Red Lake, Canada has been used to determine Nitric Oxide (NO) concentrations.
TL;DR: The effects of the solar eclipse of 26 February 1979 on the ionosphere were measured using differential Doppler techniques as mentioned in this paper, which yielded a measurement of the vertical columnar electron content along a north-south line.
TL;DR: Enhanced killing of bacteria was obtained by radiation reaching the earth during total solar eclipse than during the corresponding time of a normal day during February 16, 1980.
Abstract: Enhanced killing of bacteria was obtained by radiation reaching the earth during total solar eclipse (February 16, 1980) than during the corresponding time of a normal day (February 26, 1980). The killing was not due to the formation of sunlight induced photoproducts of tryptophan. The damage to the bacteria exposed to sunlight could be repaired by photoreactivation.
01 Jan 1983
TL;DR: It appears that changes in atmospheric light and temperature brought about by eclipse altered the behaviour of the snail and this has affected the emergence of cercariae.
Abstract: The effect of solar eclipse on the emergence of five species of freshwater cercariae from their snail hosts has been studied. Two cercariae showed visible changes from their normal emergence pattern from the snails during eclipse. It appears that changes in atmospheric light and temperature brought about by eclipse altered the behaviour of the snail and this has affected the emergence of cercariae.
Journal Article•
TL;DR: The photometrie absolue en lumiere blanche de la Couronne entre 1,03 and 6,00 rayons solaires durant cette eclipse which a pratiquement coincidee avec le maximum d'activite du cycle 21 as discussed by the authors.
Abstract: Resultats de la photometrie absolue en lumiere blanche de la couronne entre 1,03 et 6,00 rayons solaires durant cette eclipse qui a pratiquement coincidee avec le maximum d'activite du cycle 21
TL;DR: In this paper, the authors describe globale de l'eclipse and des phenomenes qui l'ont accompagne, and describe the geomagnetiques Kp, Ap, nombre de Zurich
TL;DR: In this article, the authors used the extinction of solar hydrogen Lyman-alpha radiation made during the solar eclipses of 20 May 1966 at Karistos for normal and 44% visibility and of 7 March 1970 at East Quoddy for normal, 10% and 0.6% visibility to study the variation of temperature in the mesosphere during these events.
Abstract: Rocket-borne observations of the extinction of solar hydrogen Lyman-alpha radiation made during the solar eclipses of 20 May 1966 at Karistos for normal and 44% visibility and of 7 March 1970 at East Quoddy for normal, 10% and 0.6% visibility have been used to study the variation of temperature in the mesosphere during these events. It is seen that near the mesopause the decrease of temperature at Karistos is by 20° K for 44% visibility and at East Quoddy by 100° K for 0.6% visibility. Possible causes of these temperature variationsvis-a-vis molecular oxygen and pressure variations have been briefly discussed.
01 Dec 1983
Journal Article•
TL;DR: In this article, the authors reported on the MEM power spectrum analysis of brightness temperature fluctuations observed at 2.8 GHz during the total solar eclipse of 16 February 1980, and the observed periodicities range from 3.5 min to 64 min.
Abstract: In this paper we report on the MEM power spectrum analysis of brightness temperature fluctuations observed at 2.8 GHz during the total solar eclipse of 16 February 1980. The observed periodicities range from 3.5 min to 64 min. These periodicities may arise due to spatial and/or temporal variations in the solar radio emission. The observed periodicities imply presence of scale sizes ranging from 70,000 to 600,000 km assuming that the brightness fluctuations arise because of spatial variation only. On the other hand, if these fluctuations are due to temporal variation, the observed periodicities correspond well to predicted modes of solar global oscillations.
TL;DR: In this paper, the P78-1 satellite passed near Red Lake, Ontario, at an altitude of ~600 km. On two consecutive orbits spanning the time of total eclipse, energetic electrons were measured with two silicon solid state detector spectrometers having excellent energy and angular resolution.
TL;DR: In this paper, field strength and fading observed on HF communication links during the total solar eclipse of 16th February 1980 were analyzed in terms of absorption and fading, and the observed behaviour at these two frequencies was explained in terms OFS and fading.
Abstract: Measurements of field strength and fading observed on HF Communication links Bombay-Madras and Nagpur-Madras on 13406 kHz and 9067 kHz respectively during the total solar eclipse of 16th February 1980 are presented. The observed behaviour at these two frequencies is explained in terms of absorption and fading. Field strengths on short waves record an increase during the eclipse. Marked increase in fading which is probably due to bending of the ionosphere at the time of totality is discussed.