Recent Solar Eclipse Research Articles

A Solar Eclipse: Excitement Is in the Air

A solar eclipse is a unique and exciting event that involves the Earth, moon, and Sun. During a solar eclipse, the moon covers the Sun entirely or partially. As a result, the moon temporarily blocks the sunlight coming toward Earth. Solar eclipses also change Earth’s atmosphere by affecting how close tiny particles called electrons are to each other. These electron density changes can be measured over various regions of the Earth by a group of satellites called the Global Navigation Satellite Systems (GNSS). In this article, we will tell you about changes in electron density seen during two recent solar eclipses. This is important because these changes can affect satellite-based navigation (like the GPS on your phone) and communication.

Assessment of spectra of solar radiation during the partial solar eclipse of 21 June 2020 at, Tanta, Egypt

ABSTRACT The main objective of this study is to obtain vartiation of solar spectrum during the recent solar eclipse in the range 350-1100nm. The net results are studying the spectral composition of global solar radiation which are collective of the direct and diffuse solar radiation values do not similar to the computation result (45% covering of the solar disk). The maximum absorption energy in the atmosphere is at range 820–900nm. The depression in the solar enenrgy is 0.11 (W.m-2.nm-1). The ultraviolet band is suffering low depression with respect to another bands but not given any risks on the human life as common. That the change in meteorological parameter related to variability in the solar spectrum that shift the short wave before 600 nmto long wave around 1000 nm. The most extreme drop in the solar spectrum lies in the interval which consists of the normal peak of the solar spectrum from 500 - 600nm. The percentage of radiant energy reaching the earth through 350-1100nm at the maximum of the solar eclipse was 54%. Consequently, the rate of depresion in energy is equal to 46%, which is very strange compared to the normal flow rate of 44%. During the eclipse, the maximum solar energy at the maximum eclipse are at 480nm (13.07 W.m-2.nm-1) and 630nm (13.17 W.m-2.nm-1). At the wavelength 580nm rpresents the absorbition of O2 , andthe absorbtion of H2O at 680, 730, 780 and the maximum absorbtion energy by the H2O is at 830nm (low enegy transimmted at 0.31 W.m-2.nm-1).

Changes in the D region associated with three recent solar eclipses in the South Pacific region

AbstractWe estimate D region changes due to 22 July 2009 total solar eclipse (SE), 13–14 November 2012 total SE, and 9–10 May 2013 annular SE, using VLF navigational transmitters signal observations at Suva, Fiji. The North West Cape (NWC) signal (19.8 kHz) showed an amplitude and phase decrease of 0.70 dB and 23° during November SE and 2.0 dB and 90° during May SE. The modeling using Long Wave Propagation Capability code for NWC‐Suva path during November and May SEs showed an increase in average D region reflection height (H′) and sharpness factor (β) by 0.6 and 0.5 km and 0.012 and 0.015 km−1, respectively. The July total SE for JJI‐Suva path showed an increase in H′ of 1.5 km and a decrease in β of 0.055 km−1. The decrease in the electron density calculated using SE time H′ and β is maximum for July total SE and minimum for May annular SE. The effective recombination coefficient estimated from the decay and recovery of signal phase associated with May annular SE was higher (27%) than normal daytime value 5.0 × 10−7 cm−3 s−1 and varied between 1.47 × 10−6 and 1.15 × 10−7 cm−3 s−1 in the altitude 70 to 80 km. Morlet wavelet analysis of signals amplitude shows strong wave‐like signatures (WLS) associated with three SEs with period ranging 24–66 min, but the intensity and duration of WLS show no clear dependence on SE magnitude and type. Apart from the cooling spot, the eclipse shadow can also generate WLS associated with atmospheric gravity waves.

Eclipses Observed by Large Yield RAdiometer (LYRA) – A Sensitive Tool to Test Models for the Solar Irradiance

We analyze the light curves of the recent solar eclipses measured by the Herzberg channel (200-220 nm) of the Large Yield RAdiometer (LYRA) onboard PROBA-2. The measurements allow us to accurately retrieve the center- to-limb variations (CLV) of the solar brightness. The formation height of the radiation depends on the observing angle so the examination of the CLV provide information about a broad range of heights in the solar atmosphere. We employ the 1D NLTE radiative transfer COde for Solar Irradiance (COSI) to model the measured light curves and corresponding CLV dependencies. The modeling is used to test and constrain the existing 1D models of the solar atmosphere, e.g. the temperature structure of the photosphere and the treatment of the pseudo- continuum opacities in the Herzberg continuum range. We show that COSI can accurately reproduce not only the irradiance from the entire solar disk, but also the measured CLV. It hence can be used as a reliable tool for modeling the variability of the spectral solar irradiance.

Spectral character of VLF sferics propagating inside the Earth‐ionosphere waveguide during two recent solar eclipses

Effects of solar eclipses on the propagation characteristics of worldwide VLF sferics from lightning activity require more investigation. An attempt was made on the occasion of two solar eclipses during 22nd July, 2009 and 15th January, 2010 to study the effects of the two eclipses on the propagation characteristics of VLF sferics in the Earth‐ionosphere waveguide. Identical experimental setups were used to study the VLF sferics during the two eclipse events. The spectral character of VLF sferics propagating inside the waveguide is studied at a fixed receiver location (23.75°N, 91.25°E) at six discrete frequencies in between 3 and 20 kHz. During both the eclipse events, it is observed that VLF sferics at all the six discrete frequencies is increased from the mean normal average ambient level. The increment peaks around 10–12 kHz with an overall increment of 6.4 dB with respect to its ambient level. The VLF spectral character of enhancement of sferics show similar characters in two eclipses. The percentage decrease in electron density using standard modeling equations is found to be 90% at the height of 71 km for both the eclipses, supporting linear variation of electron density with solar radiation at the D‐region of the ionosphere. The results are explained qualitatively on the basis of a decrease in electron density at the lower ionosphere modifying the reflection coefficient which affected the propagation of VLF sferics in Earth‐ionosphere waveguide during eclipsed condition.

The effects of recent solar eclipse upon a subionospheric transmitted signal

Continuous recording of a subionospheric transmitted signal at 16.4 kHz from Novik, Norway (66° 58′ N, 13° 54′ E) is being carried out in Kolkata (22° 34′ N, 88° 30′ E). The effects of recent solar eclipse on August 1, 2008 over this transmitted signal have been reported in this paper. The variations of normalized amplitude of this signal and its phase retardation in the path during the solar eclipse are measured which show significant deviations from their usual values for the same period of the control days.

Resonances

Two recent solar eclipses observable over wide areas of the North American continent, plus last year's well observed event in North Africa, have prompted Michael Mendillo and Richard Hart, of the astronomy department at Boston University, to examine the total-eclipse situation in some detail. Here is a (somewhat abbreviated) account of their paper on “Total Solar Eclipses, Extraterrestrial Life, and the Existence of God”:

Ionospheric effects of two recent solar eclipses

Ionosonde observations and Faraday rotation measurements of total electron content are used to study the effects observed in the E- and F-regions of the ionosphere during the total eclipse of 7 March 1970 and during the annular eclipse of 11 September 1969. The E-region effects are interpreted in terms of discrete ionization sources located over the photospheric disk and in the unocculted portions of the solar corona. The relative intensities of the individual sources are estimated. The bottomside F-region shows complex changes including the formation of an intermediate F1-layer during the March eclipse at medium latitude stations. Travelling ionospheric disturbances (TID's), some of which are probably eclipse-induced, are also observed. Analysis of the eclipse variations of electron density in the bottomside F-region gives an electron production rate of about 1000 cm −3sec −1 at a height of 300 km for the fairly active solar conditions of the March eclipse. The corresponding electron loss-coefficient β at this height is 8 × 10 −4 sec −1. Fractional reductions of about 30 per cent are observed in the total electron content of the ionosphere during both the eclipses. Much of this reduction occurs in the topside ionosphere and is presumably accompanied by transport effects induced by the rapid cooling of the electron gas.

Observations on the Solar Eclipse of October 2

DURING the recent solar eclipse of October 2, 1959, measurements were made at the U.S. Air Force Cambridge Research Center's radio astronomy site at Hamilton, Massachusetts. At this location the Sun rose partially eclipsed and 10 min. later it was totally eclipsed at an elevation of about 1°.

Radio Data During the Recent Solar Eclipse

Radio Data During the Recent Solar Eclipse

Radio Data During the Recent Solar Eclipse

Radio Data During the Recent Solar Eclipse

An Effect of the Recent Solar Eclipse on the Ionized Layers of the Upper Atmosphere

An Effect of the Recent Solar Eclipse on the Ionized Layers of the Upper Atmosphere

An Effect of the Recent Solar Eclipse on the Ionized Layers of the Upper Atmosphere

An Effect of the Recent Solar Eclipse on the Ionized Layers of the Upper Atmosphere

Our Astronomical Column

THE RECENT SOLAR ECLIPSE.—Many preliminary accounts of the solar eclipse of April 17 are given in the May number of L'Astronomie; the June number is to be devoted to a fuller discussion.

Our Astronomical Column

THE RECENT SOLAR ECLIPSE IN INDIA.—From a brief paragraph which appears in the Pioneer Mail for January 25 we learn that some interesting photographs of the partial eclipse of the sun were obtained at Dehra Dun (N.W. Prov. India) on January 14. A drop in the temperature of 4° corresponded with the passage of the shadow, and there was a very marked decrease in the illumination of the surrounding landscape. Venus became clearly visible to the naked eye.

Our Astronomical Column

ITALIAN OBSERVATIONS OF THE RECENT SOLAR ECLIPSE.— A series of valuable observations of the partial eclipse of the sun was made at Aosta (Italy) on August 30, and the results are given in No. 17 (1905) of the Comptes rendus.

Our Astronomical Column

THE RECENT SOLAR ECLIPSE.—M. Tisserand furnishes a few details on the results obtained by the Russian astronomers during the eclipse of August last, which were communicated to him through M. Backlund, Director of the Observatory of Pulkowa. M. Backlund's station was situated in Novaya Zemlya, where he landed three weeks before the day of the eclipse. During this period the sky remained constantly cloudy, the temperature varying from 0° to 3° C. During some occasionally bright moments altitudes of the sun were obtained to check their chronometers and determine their rates. M. Galitzine made a series of magnetic observations. At four o'clock on the morning of the eclipse the sky was still overcast, but the weather cleared up somewhat, and the observers were able to observe the four contacts under good conditions. Clouds, however, were not entirely absent; but successful observations and photographs of the corona were taken.

Our Astronomical Column

THE RECENT SOLAR ECLIPSE.—Prof. H. Geelmuyden communicates to Astr. Nachr., No. 3378) some of the observations made at this eclipse. M. Schroeter, of the Observatory of Christiania, noted the time of the arrival of the shadow from his station near Vadsö as 16h. 57m. O˙5s Central European time, with an error of ±0˙5s., the end of totality occurring at 16h. 58m. 41s. with a possible error of several seconds. He remarks also of the “peu d'obscurité” during totality. In spite of the clouds, he says he could read and write without difficulty at a distance of 50 cm., and could follow the seconds hand on the face of his chronometer, placed at a distance of 1˙4 metres. This, however, was not the experience of the observers across the Varanger Fjord on the island at Kiö.

The Solar Aurora Theory

IN the very interesting lecture of Mr. Lockyer upon the recent solar eclipse which has just appeared in NATURE, he says, speaking of the green line layer above the hydrogen, “Here obviously we have, I think, merely an indication of another substance thinning out, in spite of the extraordinary suggestion which was put forward that the corona was nothing but a permanent solar aurora.”

Science at Oxford

THE following courses of lectures in Science are announced for the ensuing term:—The Regius Professor of Medicine (Dr. Acland) will continue his clinical instruction at the Infirmary, on Tuesdays and Saturdays, beginning on Tuesday, May 2, at 11 A.M. The Linacre Professor of Anatomy and Physiology (Dr. Rolleston) proposes to form classes for practical instruction in anatomy and physiology, as in former terms. Persons are invited to come to the anatomical department in the New Museum on two mornings of the week for study and demonstration, and to lectures on Saturdays at 1 P.M., and at such other times as maybe hereafter arranged. The Sedleian Professor of Natural Philosophy (the Rev. Bartholomew Price) will give a course of lectures on the Solution of Problems in Applied Mathematics. The course will begin at 1 P.M. on Thursday, April 20, in the lecture-room, upper corridor south, Museum. The Savilian Professor of Astronomy (the Rev. C. Pritchard) will give a lecture early in the present term on the recent solar eclipse. He will also be ready to assist members of the University in their astronomical studies, “sine ulla solenniiate” The Savilian Professor of Geometry (Mr. Henry Smith) will continue his lectures on the Anharmonic Properties of Figures. He will also give a course of lectures on Geometry of Three Dimensions. The Professor of Geology (Mr. J. Phillips) will begin a course of lectures on Monday, April 24, at 12 o'clock, and continue them at the same hour on succeeding Wednesdays and Mondays, in the New Museum. The lectures are arranged to present a systematic view of the more remarkable groups of organic remains, especially in the extinct groups. The Professor of Experimental Philosophy (Mr. R. B. Clifton) has given notice that the Physical Laboratory of the University will be open daily for instruction in practical physics, from 10 A.M. to 4 P.M., on and after Wednesday, April 19. The fee for working three days a week during the term is 3l. The Professor of Chemistry (Sir B. Brodie) has given notice that the Demonstrator in Chemistry will deliver a course of lectures on Chemistry on Tuesdays and Saturdays, at u A.M., commencing Tuesday, April 25. These lectures will be in continuation of the course of the Professor of Chemistry last term, and will commence with the element phosphorus and its combinations. The Professor of Botany (Mr. Lawson) will give a course of lectures on Structural and Physiological Botany. The Hope Professor of Zoology (Mr. Westwood) proposes to give a short course of lectures on the Articulated Animals.