WorldWideScience

Sample records for hybrid solar eclipse

  1. The Solar Eclipse

    Science.gov (United States)

    Stern, David

    1970-01-01

    Instructions for observing the Solar Eclipse on Saturday, March 7, 1970, which will be total along a strip about 85 miles wide along the Atlantic Seaboard. Safety precautions and how to construct a pinhole camera to observe eclipse. (BR)

  2. The Solar Eclipse

    Science.gov (United States)

    Stern, David

    1970-01-01

    Instructions for observing the Solar Eclipse on Saturday, March 7, 1970, which will be total along a strip about 85 miles wide along the Atlantic Seaboard. Safety precautions and how to construct a pinhole camera to observe eclipse. (BR)

  3. Atmospheric changes from solar eclipses

    CERN Document Server

    Aplin, Karen; Gray, Suzanne

    2016-01-01

    This article reviews atmospheric changes associated with 44 solar eclipses, beginning with the first quantitative results available, from 1834 (earlier qualitative, accounts also exist). Eclipse meteorology attracted relatively few publications until the total solar eclipse of 16 February 1980, with the 11 August 1999 eclipse producing the most papers. Eclipses passing over populated areas such as Europe, China and India now regularly attract scientific attention, whereas atmospheric measurements of eclipses at remote locations remain rare. Many measurements and models have been used to exploit the uniquely predictable solar forcing provided by an eclipse. In this paper we compile the available publications and review a sub-set of them chosen on the basis of importance and novelty. Beyond the obvious reduction in incoming solar radiation, atmospheric cooling from eclipses can induce dynamical changes. Observations and meteorological modelling provide evidence for the generation of a local eclipse circulation ...

  4. Atmospheric changes from solar eclipses.

    Science.gov (United States)

    Aplin, K L; Scott, C J; Gray, S L

    2016-09-28

    This article reviews atmospheric changes associated with 44 solar eclipses, beginning with the first quantitative results available, from 1834 (earlier qualitative accounts also exist). Eclipse meteorology attracted relatively few publications until the total solar eclipse of 16 February 1980, with the 11 August 1999 eclipse producing the most papers. Eclipses passing over populated areas such as Europe, China and India now regularly attract scientific attention, whereas atmospheric measurements of eclipses at remote locations remain rare. Many measurements and models have been used to exploit the uniquely predictable solar forcing provided by an eclipse. In this paper, we compile the available publications and review a subset of them chosen on the basis of importance and novelty. Beyond the obvious reduction in incoming solar radiation, atmospheric cooling from eclipses can induce dynamical changes. Observations and meteorological modelling provide evidence for the generation of a local eclipse circulation that may be the origin of the 'eclipse wind'. Gravity waves set up by the eclipse can, in principle, be detected as atmospheric pressure fluctuations, though theoretical predictions are limited, and many of the data are inconclusive. Eclipse events providing important early insights into the ionization of the upper atmosphere are also briefly reviewed.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  5. Cajal on solar eclipse.

    Science.gov (United States)

    Triarhou, Lazaros C; del Cerro, Manuel

    2008-01-01

    An impression that sculpted a lasting memory on the mind of the great neuroanatomist Santiago Ramón y Cajal, an 8-year-old boy at the time, was the total solar eclipse of 18 July 1860. This short article provides a translation of the relevant passage, found in a 1933 Buenos Aires schoolbook, and places the celestial event at the crossroads of neuroscience, astronomy and literature.

  6. Solar Eclipses Observed from Antarctica

    OpenAIRE

    2013-01-01

    Aspects of the solar corona are still best observed during totality of solar eclipses, and other high-resolution observations of coronal active regions can be observed with radio telescopes by differentiation of occultation observations, as we did with the Jansky Very Large Array for the annular solar eclipse of 2012 May 20 in the US. Totality crossing Antarctica included the eclipse of 2003 November 23, and will next occur on 2021 December 4; annularity crossing Antarctica included the eclip...

  7. Retinopathy after solar eclipse, 1995.

    Science.gov (United States)

    Verma, L; Sharma, N; Tewari, H K; Gupta, S

    1996-01-01

    Visual damage following direct sighting of the solar eclipse is a well established clinical entity. In spite of warnings in the media, a number of people attempted to observe the solar eclipse. Consequently, some developed visual damage. Twenty-one patients were referred to the Solar Eclipse Cell at our centre. Their demographic and clinical features were evaluated. Foveal findings correlated with the duration of exposure and frequency of watching the eclipse. Six patients had used protective devices for viewing the eclipse. More than 47% eyes had discernible fundus lesions. Lasting visual damage can follow a solar retinal burn with little or no protection from the viewing devices. Prevention remains the best treatment and there is a need to educate the public in this regard.

  8. Eclipse A Brief Introduction of 2008 Solar Eclipse

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The 2008 solar total eclipse starts from North of Canada,passes through Greenland,Arctic,Novosibirsk and North of China.This is the first solar total eclipse in China in the 21st centary.Date and time:August 1,2008,11:00 UT Eclipse site in China:Altay,Hami (Xinjiang),Jiuquan,Lanzhou (Gansu), Xi’an(Shanxi)

  9. Heliophysics at total solar eclipses

    Science.gov (United States)

    Pasachoff, Jay M.

    2017-08-01

    Observations during total solar eclipses have revealed many secrets about the solar corona, from its discovery in the 17th century to the measurement of its million-kelvin temperature in the 19th and 20th centuries, to details about its dynamics and its role in the solar-activity cycle in the 21st century. Today's heliophysicists benefit from continued instrumental and theoretical advances, but a solar eclipse still provides a unique occasion to study coronal science. In fact, the region of the corona best observed from the ground at total solar eclipses is not available for view from any space coronagraphs. In addition, eclipse views boast of much higher quality than those obtained with ground-based coronagraphs. On 21 August 2017, the first total solar eclipse visible solely from what is now United States territory since long before George Washington's presidency will occur. This event, which will cross coast-to-coast for the first time in 99 years, will provide an opportunity not only for massive expeditions with state-of-the-art ground-based equipment, but also for observations from aloft in aeroplanes and balloons. This set of eclipse observations will again complement space observations, this time near the minimum of the solar activity cycle. This review explores the past decade of solar eclipse studies, including advances in our understanding of the corona and its coronal mass ejections as well as terrestrial effects. We also discuss some additional bonus effects of eclipse observations, such as recreating the original verification of the general theory of relativity.

  10. The Total Solar Eclipse, March 1970

    Science.gov (United States)

    Glenn, William H.

    1970-01-01

    Describes the circumstances of the total and partial solar eclipse of March 7, 1970 in certain American cities. Also discussed are (1) a classroom demonstration of the cause of solar eclipses, (2) techniques for safely observing the eclipse, and (3) what to observe during the eclipse. Bibliography. (LC)

  11. The Total Solar Eclipse, March 1970

    Science.gov (United States)

    Glenn, William H.

    1970-01-01

    Describes the circumstances of the total and partial solar eclipse of March 7, 1970 in certain American cities. Also discussed are (1) a classroom demonstration of the cause of solar eclipses, (2) techniques for safely observing the eclipse, and (3) what to observe during the eclipse. Bibliography. (LC)

  12. Annular and Total Solar Eclipses of 2010

    Science.gov (United States)

    Espenak, Fred; Anderson, J.

    2008-01-01

    While most NASA eclipse bulletins cover a single eclipse, this publication presents predictions for two solar eclipses during 2010. This has required a different organization of the material into the following sections. Section 1 -- Eclipse Predictions: The section consists of a general discussion about the eclipse path maps, Besselian elements, shadow contacts, eclipse path tables, local circumstances tables, and the lunar limb profile. Section 2 -- Annular Solar Eclipse of 2010 Ja n 15: The section covers predictions and weather prospects for the annular eclipse. Section 3 -- Total Solar Eclipse of 2010 Jul 11: The se ction covers predictions and weather prospects for the total eclipse. Section 4 -- Observing Eclipses: The section provides information on eye safety, solar filters, eclipse photography, and making contact timings from the path limits. Section 5 -- Eclipse Resources: The final section contains a number of resources including information on the IAU Working Group on Eclipses, the Solar Eclipse Mailing List, the NASA eclipse bulletins on the Internet, Web sites for the two 2010 eclipses, and a summary identifying the algorithms, ephemerides, and paramete rs used in the eclipse predictions.

  13. Orbital View of Solar Eclipse

    Science.gov (United States)

    2002-01-01

    International Space Station (ISS) crew members were able to document a rare occurrence. The dark area near the center of the frame is actually a shadow cast by the moon during the total solar eclipse of December 4, 2002. The shadow obscures an area of cloud cover. The Station, with three Expedition Six crew members aboard, was over the Indian Ocean at the time of the eclipse.

  14. Detection and Analysis of Solar Eclipse

    OpenAIRE

    2012-01-01

    We propose an algorithm that can be used by amateur astronomers to analyze the images acquired during solar eclipses. The proposed algorithm analyzes the image, detects the eclipse and produces results for parameters like magnitude of eclipse, eclipse obscuration and the approximate distance between the Earth and the Moon.

  15. Spectropolarimetry of Solar Corona during Solar Eclipses

    Science.gov (United States)

    Qu, Zhongquan

    2017-08-01

    We present the results from spectropolarimetry of solar corona. These observations were conducted during solar eclipses in 2008 China, 2013 Gabon, and probably 2017 United States of America respectively. From the former two observations, it is shown that the patterns of linear polarization of radiation from the solar corona are very abundant, and the abundance may be related to the complexity of mass motions and magnetic configuration in the corona. And the spectropolarimetry during solar eclipses may open a new window to probe precisely the physical features of the local corona, especially its magnetic configuration.

  16. Total Solar Eclipse--A Caribbean Adventure.

    Science.gov (United States)

    Green, Steven; Tunstall, Louisa; Tunstall, Neil

    1999-01-01

    Describes the experiences of two high school students who traveled to the Caribbean island of Curacao to view a total solar eclipse and prepare methods for teaching classmates about the eclipse the following school year. (Author/WRM)

  17. Total Solar Eclipse--A Caribbean Adventure.

    Science.gov (United States)

    Green, Steven; Tunstall, Louisa; Tunstall, Neil

    1999-01-01

    Describes the experiences of two high school students who traveled to the Caribbean island of Curacao to view a total solar eclipse and prepare methods for teaching classmates about the eclipse the following school year. (Author/WRM)

  18. Resource Letter OSE-1: Observing Solar Eclipses

    Science.gov (United States)

    Pasachoff, Jay M.; Fraknoi, Andrew

    2017-07-01

    This Resource Letter provides a guide to the available literature, listing selected books, articles, and online resources about scientific, cultural, and practical issues related to observing solar eclipses. It is timely, given that a total solar eclipse will cross the continental United States on August 21, 2017. The next total solar eclipse path crossing the U.S. and Canada will be on April 8, 2024. In 2023, the path of annularity of an annular eclipse will cross Mexico, the United States, and Canada, with partial phases visible throughout those countries.

  19. Solar Eclipse, STEREO Style

    Science.gov (United States)

    2007-01-01

    There was a transit of the Moon across the face of the Sun - but it could not be seen from Earth. This sight was visible only from the STEREO-B spacecraft in its orbit about the sun, trailing behind the Earth. NASA's STEREO mission consists of two spacecraft launched in October, 2006 to study solar storms. The transit starts at 1:56 am EST and continued for 12 hours until 1:57 pm EST. STEREO-B is currently about 1 million miles from the Earth, 4.4 times farther away from the Moon than we are on Earth. As the result, the Moon will appear 4.4 times smaller than what we are used to. This is still, however, much larger than, say, the planet Venus appeared when it transited the Sun as seen from Earth in 2004. This alignment of STEREO-B and the Moon is not just due to luck. It was arranged with a small tweak to STEREO-B's orbit last December. The transit is quite useful to STEREO scientists for measuring the focus and the amount of scattered light in the STEREO imagers and for determining the pointing of the STEREO coronagraphs. The Sun as it appears in these the images and each frame of the movie is a composite of nearly simultaneous images in four different wavelengths of extreme ultraviolet light that were separated into color channels and then recombined with some level of transparency for each.

  20. Solar Eclipse, STEREO Style

    Science.gov (United States)

    2007-01-01

    There was a transit of the Moon across the face of the Sun - but it could not be seen from Earth. This sight was visible only from the STEREO-B spacecraft in its orbit about the sun, trailing behind the Earth. NASA's STEREO mission consists of two spacecraft launched in October, 2006 to study solar storms. The transit starts at 1:56 am EST and continued for 12 hours until 1:57 pm EST. STEREO-B is currently about 1 million miles from the Earth, 4.4 times farther away from the Moon than we are on Earth. As the result, the Moon will appear 4.4 times smaller than what we are used to. This is still, however, much larger than, say, the planet Venus appeared when it transited the Sun as seen from Earth in 2004. This alignment of STEREO-B and the Moon is not just due to luck. It was arranged with a small tweak to STEREO-B's orbit last December. The transit is quite useful to STEREO scientists for measuring the focus and the amount of scattered light in the STEREO imagers and for determining the pointing of the STEREO coronagraphs. The Sun as it appears in these the images and each frame of the movie is a composite of nearly simultaneous images in four different wavelengths of extreme ultraviolet light that were separated into color channels and then recombined with some level of transparency for each.

  1. [Optical coherence tomography in solar eclipse retinopathy].

    Science.gov (United States)

    Calvo-González, C; Reche-Frutos, J; Santos-Bueso, E; Díaz-Valle, D; Benítez-del-Castillo, J M; García-Sánchez, J

    2006-05-01

    We describe the case of a patient suffering from acute visual loss soon after watching a solar eclipse. Optical coherence tomography was the main diagnostic tool used. Solar retinopathy is now an unusual cause of visual loss, although there are still some cases diagnosed, especially after viewing solar eclipses. Optical coherence tomography is suitable for detecting permanent retinal injuries related to solar exposure, with the outer retinal layers being typically affected.

  2. American Solar Eclipses 2017 & 2024

    Science.gov (United States)

    DiCanzio, Albert

    2016-06-01

    This research focuses on harnessing the statistical capacity of many available concurrent observers to advance scientific knowledge. By analogy to some Galilean measurement-experiments in which he used minimal instrumentation, this researcher will address the question: How might an individual observer, with a suitably chosen common metric and with widely available, reasonably affordable equipment, contribute to new knowledge from observing the solar eclipse of 2017? Each observer would report data to an institutional sponsor who would analyze these data statistically toward new knowledge about some question currently unsettled in astronomy or in the target field connected with the question which the chosen metric is targeted to address. A subordinate question will be discussed: As a tradeoff between “best question to answer” and “easiest question for observers’ data to answer”, is there an event property and related target question that, with high potential utility and low cost, would be measurable by an observer positioned in the path of totality with minimal or inexpensive equipment and training? (And that, as a statistical sample point, might contribute to new knowledge?) In dialog with the audience, the presenter will suggest some measurables; e.g., solar flares, ground shadow bands, atmospheric metrics, coronal structure, etc., correlated or not with certain other dependent variables. The independent variable would be time in the intervention interval from eclipse contacts 1 -- 4. By the aforementioned analogy, the presenter will review as examples some measurement-experiments conducted or suggested by Galileo; e.g., pendulum laws, Jovian satellite eclipse times, geokinesis as later seen in Bessel's parallactic measurement, and Michelson's measurement of light speed. Because criteria of metrics-determination would naturally include existence of a data-collection-analysis method, this presentation requires dialogue with a critical mass of audience

  3. Scientific observations at total solar eclipses

    Institute of Scientific and Technical Information of China (English)

    Jay M.Pasachoff

    2009-01-01

    The occasion of the longest totality of an eclipse in the 18 yr 111/3 d saros cycle leads to taking stock of the scientific value of ground-based eclipse observations in this space age. Though a number of space satellites from the U.S., Europe, Japan, and Russia study the Sun, scientists at eclipses can observe the solar chromosphere and corona at higher spatial resolution, at higher temporal resolution, and at higher spectral resolution than are possible aloft. Furthermore, eclipse expeditions can transport a wide variety of state-of-the-art equipment to the path of totality. Thus, for at least some years to come, solar eclipse observations will remain both scientifically valuable and cost-effective ways to study the outer solar atmosphere.

  4. Central Serous Chorioretinopathy after Solar Eclipse Viewing

    Directory of Open Access Journals (Sweden)

    Allie Lee

    2010-01-01

    Full Text Available Purpose: To report a case of central serous chorioretinopathy after solar eclipse viewing. Case Report: A middle-age man developed a sudden-onset unilateral scotoma after viewing a partial solar eclipse in Hong Kong. Fundus examination, fluorescein angiography, and optical coherence tomography showed features compatible with central serous chorioretinopathy. The patient was managed conservatively and reevaluated periodically. Serial optical coherence tomographic evaluations demonstrated an initial increase in the amount of subretinal fluid which spontaneously resolved 10 weeks after the onset of symptoms. Conclusion: This case demonstrates the possibility of development of central serous chorioretinopathy following solar eclipse viewing.

  5. Central serous chorioretinopathy after solar eclipse viewing.

    Science.gov (United States)

    Lee, Allie; Lai, Timothy Y Y

    2010-07-01

    To report a case of central serous chorioretinopathy after solar eclipse viewing. A middle-age man developed a sudden-onset unilateral scotoma after viewing a partial solar eclipse in Hong Kong. Fundus examination, fluorescein angiography, and optical coherence tomography showed features compatible with central serous chorioretinopathy. The patient was managed conservatively and reevaluated periodically. Serial optical coherence tomographic evaluations demonstrated an initial increase in the amount of subretinal fluid which spontaneously resolved 10 weeks after the onset of symptoms. This case demonstrates the possibility of development of central serous chorioretinopathy following solar eclipse viewing.

  6. Paper Moon: Simulating a Total Solar Eclipse

    Science.gov (United States)

    Madden, Sean P.; Downing, James P.; Comstock, Jocelyne M.

    2006-01-01

    This article describes a classroom activity in which a solar eclipse is simulated and a mathematical model is developed to explain the data. Students use manipulative devices and graphing calculators to carry out the experiment and then compare their results to those collected in Koolymilka, Australia, during the 2002 eclipse.

  7. Paper Moon: Simulating a Total Solar Eclipse

    Science.gov (United States)

    Madden, Sean P.; Downing, James P.; Comstock, Jocelyne M.

    2006-01-01

    This article describes a classroom activity in which a solar eclipse is simulated and a mathematical model is developed to explain the data. Students use manipulative devices and graphing calculators to carry out the experiment and then compare their results to those collected in Koolymilka, Australia, during the 2002 eclipse.

  8. Solar Eclipse Effect on Shelter Air Temperature

    Science.gov (United States)

    Segal, M.; Turner, R. W.; Prusa, J.; Bitzer, R. J.; Finley, S. V.

    1996-01-01

    Decreases in shelter temperature during eclipse events were quantified on the basis of observations, numerical model simulations, and complementary conceptual evaluations. Observations for the annular eclipse on 10 May 1994 over the United States are presented, and these provide insights into the temporal and spatial changes in the shelter temperature. The observations indicated near-surface temperature drops of as much as 6 C. Numerical model simulations for this eclipse event, which provide a complementary evaluation of the spatial and temporal patterns of the temperature drops, predict similar decreases. Interrelationships between the temperature drop, degree of solar irradiance reduction, and timing of the peak eclipse are also evaluated for late spring, summer, and winter sun conditions. These simulations suggest that for total eclipses the drops in shelter temperature in midlatitudes can be as high as 7 C for a spring morning eclipse.

  9. The solar eclipse: a natural meteorological experiment.

    Science.gov (United States)

    Harrison, R Giles; Hanna, Edward

    2016-09-28

    A solar eclipse provides a well-characterized reduction in solar radiation, of calculable amount and duration. This captivating natural astronomical phenomenon is ideally suited to science outreach activities, but the predictability of the change in solar radiation also provides unusual conditions for assessing the atmospheric response to a known stimulus. Modern automatic observing networks used for weather forecasting and atmospheric research have dense spatial coverage, so the quantitative meteorological responses to an eclipse can now be evaluated with excellent space and time resolution. Numerical models representing the atmosphere at high spatial resolution can also be used to predict eclipse-related changes and interpret the observations. Combining the models with measurements yields the elements of a controlled atmospheric experiment on a regional scale (10-1000 km), which is almost impossible to achieve by other means. This modern approach to 'eclipse meteorology' as identified here can ultimately improve weather prediction models and be used to plan for transient reductions in renewable electricity generation. During the 20 March 2015 eclipse, UK electrical energy demand increased by about 3 GWh (11 TJ) or about 4%, alongside reductions in the wind and photovoltaic electrical energy generation of 1.5 GWh (5.5 TJ).This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  10. The Standardisation and Sequencing of Solar Eclipse Images for the Eclipse Megamovie Project

    CERN Document Server

    Krista, Larisza

    2015-01-01

    We present a new tool, the Solar Eclipse Image Standardisation and Sequencing (SEISS), developed to process multi-source total solar eclipse images by adjusting them to the same standard of size, resolution, and orientation. Furthermore, by analysing the eclipse images we can determine the relative time between the observations and order them to create a movie of the observed total solar eclipse sequence. We successfully processed images taken at the 14 November 2012 total solar eclipse that occurred in Queensland, Australia, and created a short eclipse proto-movie. The SEISS tool was developed for the Eclipse Megamovie Project (EMP: https://www.eclipsemegamovie.org), with the goal of processing thousands of images taken by the public during solar eclipse events. EMP is a collaboration among multiple institutes aiming to engage and advance the public interest in solar eclipses and the science of the Sun-Earth connection.

  11. Effect of solar eclipse on microbes

    Directory of Open Access Journals (Sweden)

    Amrita Shriyan

    2011-01-01

    Full Text Available Objective : A solar eclipse was observed in India on 15 th January, 2010. It was a total eclipse in some parts of the country, while it was a partial eclipse in other parts. Microorganisms play an important role in various phenomena on the earth. This study was undertaken to know the influence of solar eclipse on nature indirectly, by analyzing certain genotypic and phenotypic variations in prokaryotes and eukaryotes. Since yeast have similar gene expression as that of humans, investigations were pursued on Candida albicans. Hence the study of the effect of solar eclipse on cultures of Staphylococcus aureus, Klebsiella species, Escherichia coli, and C. albicans was performed in the laboratory. The effect of the total or partial eclipse on the microorganism isolated from clinical isolates was investigated during the time period from 11.15 am to 3.15 pm. Materials and Methods : Cultures of S. aureus, Klebsiella species, and E. coli colonies on nutrient agar slants and broth and C. albicans on Sabouraud′s dextrose agar plates and broth. Slants were exposed to sunlight during eclipse and exposure to normal sunlight at Mangalore, Dakshina Kannada district, Karnataka state, India. Results : There was significant change observed during exposure to normal sunlight and eclipse phase. Bacterial colonies showed difference in morphology on smear examination and sensitivity pattern during this study. One fungal species and three bacterial isolates were studied and changes were recorded. Fungal species showed a definite change in their morphology on exposure to sunlight during eclipse observed by stained smear examination from broth, plate, and slant. Conclusion : Present study concludes that blocking of the sun rays during eclipse does not harm prokaryotes and eukaryotes, instead promoted the progeny of predators in the race of better acclimatization and survival in the natural and changing environmental conditions.

  12. Effect of solar eclipse on microbes.

    Science.gov (United States)

    Shriyan, Amrita; Bhat, Angri M; Nayak, Narendra

    2011-01-01

    A solar eclipse was observed in India on 15(th) January, 2010. It was a total eclipse in some parts of the country, while it was a partial eclipse in other parts. Microorganisms play an important role in various phenomena on the earth. This study was undertaken to know the influence of solar eclipse on nature indirectly, by analyzing certain genotypic and phenotypic variations in prokaryotes and eukaryotes. Since yeast have similar gene expression as that of humans, investigations were pursued on Candida albicans. Hence the study of the effect of solar eclipse on cultures of Staphylococcus aureus, Klebsiella species, Escherichia coli,and C. albicans was performed in the laboratory. The effect of the total or partial eclipse on the microorganism isolated from clinical isolates was investigated during the time period from 11.15 am to 3.15 pm. Cultures of S. aureus, Klebsiella species, and E. coli colonies on nutrient agar slants and broth and C. albicans on Sabouraud's dextrose agar plates and broth. Slants were exposed to sunlight during eclipse and exposure to normal sunlight at Mangalore, Dakshina Kannada district, Karnataka state, India. There was significant change observed during exposure to normal sunlight and eclipse phase. Bacterial colonies showed difference in morphology on smear examination and sensitivity pattern during this study. One fungal species and three bacterial isolates were studied and changes were recorded. Fungal species showed a definite change in their morphology on exposure to sunlight during eclipse observed by stained smear examination from broth, plate, and slant. Present study concludes that blocking of the sun rays during eclipse does not harm prokaryotes and eukaryotes, instead promoted the progeny of predators in the race of better acclimatization and survival in the natural and changing environmental conditions.

  13. Observing Solar Eclipses in the Developing World

    Science.gov (United States)

    Pasachoff, J. M.

    2006-08-01

    The paths of totality of total solar eclipses cross the world, with each spot receiving such a view about every 300 years. The areas of the world from which partial eclipses are visible are much wider. For the few days prior to a total eclipse, the attention of a given country is often drawn toward the eclipse, providing a teachable moment that we can use to bring astronomy to the public's attention. Also, it is important to describe how to observe the partial phases of the eclipse safely. Further, it is important to describe to those people in the zone of totality that it is not only safe but also interesting to view totality. Those who are misled by false warnings that overstate the hazards of viewing the eclipse, or that fail to distinguish between safe and unsafe times for naked-eye viewing, may well be skeptical when other health warnings--perhaps about AIDS or malaria prevention or polio inoculations--come from the authorities, meaning that the penalties for misunderstanding the astronomical event can be severe. Through the International Astronomical Union's Working Group on Solar Eclipses and through the I.A.U.'s Program Group on Public Education at the Times of Eclipses, part of the Commission on Education and Development, we make available information to national authorities, to colleagues in the relevant countries, and to others, through our Websites at http://www.eclipses.info and http://www.totalsolareclipse.net and through personal communication. Among our successes at the 29 March 2006 total solar eclipse was the distribution through a colleague in Nigeria of 400,000 eye-protection filters.

  14. Statistical study of the solar eclipses over Egypt during 20 centuries (1-2000)

    Science.gov (United States)

    Abdel-Rahman, H. I.; Marzouk, B. A.

    2017-06-01

    During solar eclipses the scientists can be observe and studying the solar atmosphere. The stratified structures of the solar atmosphere are mainly the photosphere, the chromosphere and the corona. In this work we used the Least Square (LS) method to investigate the statistical study of the solar eclipses during 20 centuries (1-2000). We found the formula for total number of every types of solar eclipse. We get the frequency distribution of all eclipses for 20 centuries over Egypt; the percentage ratio for partial solar eclipse is 43.2%, while the percentage ratio for the annular solar eclipse is 30.1%, and the percentage ratio for total and hybrid solar eclipses are 22.3% and 4.4% respectively. The General Linear Trend formula for predicting the future values for every types of solar eclipse was obtained and determined during next 500 years (2001-2500). We compare our results with calculated once by NASA for each types of solar eclipse. Our results are in a good agreement with that published by NASA.

  15. The solar eclipse: a natural meteorological experiment

    Science.gov (United States)

    2016-01-01

    A solar eclipse provides a well-characterized reduction in solar radiation, of calculable amount and duration. This captivating natural astronomical phenomenon is ideally suited to science outreach activities, but the predictability of the change in solar radiation also provides unusual conditions for assessing the atmospheric response to a known stimulus. Modern automatic observing networks used for weather forecasting and atmospheric research have dense spatial coverage, so the quantitative meteorological responses to an eclipse can now be evaluated with excellent space and time resolution. Numerical models representing the atmosphere at high spatial resolution can also be used to predict eclipse-related changes and interpret the observations. Combining the models with measurements yields the elements of a controlled atmospheric experiment on a regional scale (10–1000 km), which is almost impossible to achieve by other means. This modern approach to ‘eclipse meteorology’ as identified here can ultimately improve weather prediction models and be used to plan for transient reductions in renewable electricity generation. During the 20 March 2015 eclipse, UK electrical energy demand increased by about 3 GWh (11 TJ) or about 4%, alongside reductions in the wind and photovoltaic electrical energy generation of 1.5 GWh (5.5 TJ). This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550768

  16. Influence of a solar eclipse on twilight.

    Science.gov (United States)

    Geyer, E H; Hoffmann, M; Volland, H

    1994-07-20

    The morning twilight of the presunrise sky was measured at the Hoher-List Observatory during the total eclipse of 22 July 1990. The location of observation was far away from the central eclipse zone. The luminance showed a deep minimum in twilight during the main phase of the solar eclipse compared with normal conditions. A first order scattering model explains the observations reasonably well and shows that the sky radiation during the first phase of twilight at a location far away from the central umbra depends primarily on the height profile of the air pressure between ~ 100 and 200 km.

  17. Coordinated weather balloon solar radiation measurements during a solar eclipse.

    Science.gov (United States)

    Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  18. Preparing for and Observing the 2017 Total Solar Eclipse

    OpenAIRE

    2015-01-01

    I discuss ongoing plans and discussions for EPO and scientific observing of the 21 August 2017 total solar eclipse. I discuss aspects of EPO based on my experiences at the 60 solar eclipses I have seen. I share cloud statistics along the eclipse path compiled by Jay Anderson, the foremost eclipse meteorologist. I show some sample observations of composite imagery, of spectra, and of terrestrial temperature changes based on observations of recent eclipses, including 2012 from Australia and 201...

  19. Coordinated weather balloon solar radiation measurements during a solar eclipse

    Science.gov (United States)

    2016-01-01

    Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550757

  20. Behavior of Photovoltaic during the Partial Solar Eclipse in Bandung

    Science.gov (United States)

    Nandiyanto, A. B. D.; Rusli, A.; Purnamasari, A.; Abdullah, A. G.; Riza, L. S.

    2017-03-01

    The purpose of this study was to investigate the behavior of photovoltaic system during the partial solar eclipse phenomenon of 9 March 2016 in Bandung, Indonesia. In the experimental method, we monitored the impact of the solar eclipse on the photovoltaic system in solar cell system. To qualitatively explain the experimental observations, we compared the behavior of photovoltaic system in the solar eclipse day (9 March 2016) with the two sunny days (8 and 10 March 2016). The experimental results showed that the intensity and electricity power increased along with the solar light irradiation time. However, when there is a solar eclipse phenomenon, the intensity and electricity power is suddenly down.

  1. Calcification of thoracic aorta - solar eclipse sign.

    Science.gov (United States)

    Dhoble, Abhijeet; Puttarajappa, Chethan

    2008-08-29

    Calcification of thoracic aorta is very common in old people, especially ones with hypertension. This can sometime be visible on plain chest radiograph. We present a case of a male patient who had extensive deposition of calcium in the thoracic aorta. The relationship between aortic calcification and coronary atherosclerosis remains contentious. Computed tomography of the thorax can display this calcification which appears like 'solar eclipse'.

  2. Records of solar eclipse observations in ancient China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Like ancient people at other places of the world, the ancient Chinese lived in awe of the Sun. As they felt solar eclipses extremely significant events, they closely observed the occurrence of solar eclipse. Ancient astronomers further realized very early that solar eclipses were one of the important astronomical phenomena to revise and improve the ancient calendar. Interestingly, ancient emperors regarded solar eclipses as warnings from heaven that might affect the stability of their throne. Consequently, observing and recording solar eclipses became official, which dated far back to ancient China when numerous relevant descriptions were recorded in historical books. These records contribute substantially to China as an ancient civilization, as well as to the research of the long-term variation of the rotation rate of the Earth during >2000 years before the 17th century. This paper briefly reviews the perception, observations and recording of solar eclipses by ancient Chinese astronomers.

  3. Records of solar eclipse observations in ancient China

    Institute of Scientific and Technical Information of China (English)

    HAN YanBen; QIAO OiYuan

    2009-01-01

    Like ancient people at other places of the world, the ancient Chinese lived in awe of the Sun. As they felt solar eclipses extremely significant events, they closely observed the occurrence of solar eclipse. Ancient astronomers further realized very early that solar eclipses were one of the important astro-nomical phenomena to revise and improve the ancient calendar. Interestingly, ancient emperors re-garded solar eclipses as warnings from heaven that might affect the stability of their throne. Conse-quently, observing and recording solar eclipses became official, which dated far back to ancient China when numerous relevant descriptions were recorded in historical books. These records contribute substantially to China as an ancient civilization, as well as to the research of the long-term variation of the rotation rate of the Earth during >2000 years before the 17th century. This paper briefly reviews the perception, observations and recording of solar eclipses by ancient Chinese astronomers.

  4. Total solar eclipses and how to observe them

    CERN Document Server

    Mobberley, Martin

    2007-01-01

    This is the ultimate, easy-to-read guide for "eclipse-chasers" which includes everything an eclipse chaser needs. It provides a checklist of where to go to see total solar eclipses, for the next 15 years, and includes travel details.

  5. Anticipation of total solar eclipse and suicide incidence.

    Science.gov (United States)

    Voracek, Martin; Rancāns, Elmārs; Vintilă, Mona; Fisher, Maryanne

    2004-09-01

    Around the total solar eclipse of August 11 1999, suicide incidence decreased in Timiş county, Romania, a region crossed by the path of totality and subject to eclipse-trekking, whereas no such decrease was observed in Latvia, where only a partial eclipse was observed. Collective anticipation of a positive event could have a preventive effect on suicide incidence.

  6. Spectral irradiance curve calculations for any type of solar eclipse

    Science.gov (United States)

    Deepak, A.; Merrill, J. E.

    1974-01-01

    A simple procedure is described for calculating the eclipse function (EF), alpha, and hence the spectral irradiance curve (SIC), (1-alpha), for any type of solar eclipse: namely, the occultation (partial/total) eclipse and the transit (partial/annular) eclipse. The SIC (or the EF) gives the variation of the amount (or the loss) of solar radiation of a given wavelength reaching a distant observer for various positions of the moon across the sun. The scheme is based on the theory of light curves of eclipsing binaries, the results of which are tabulated in Merrill's Tables, and is valid for all wavelengths for which the solar limb-darkening obeys the cosine law: J = sub c (1 - X + X cost gamma). As an example of computing the SIC for an occultation eclipse which may be total, the calculations for the March 7, 1970, eclipse are described in detail.

  7. Solar Eclipse Computer API: Planning Ahead for August 2017

    Science.gov (United States)

    Bartlett, Jennifer L.; Chizek Frouard, Malynda; Lesniak, Michael V.; Bell, Steve

    2016-01-01

    With the total solar eclipse of 2017 August 21 over the continental United States approaching, the U.S. Naval Observatory (USNO) on-line Solar Eclipse Computer can now be accessed via an application programming interface (API). This flexible interface returns local circumstances for any solar eclipse in JavaScript Object Notation (JSON) that can be incorporated into third-party Web sites or applications. For a given year, it can also return a list of solar eclipses that can be used to build a more specific request for local circumstances. Over the course of a particular eclipse as viewed from a specific site, several events may be visible: the beginning and ending of the eclipse (first and fourth contacts), the beginning and ending of totality (second and third contacts), the moment of maximum eclipse, sunrise, or sunset. For each of these events, the USNO Solar Eclipse Computer reports the time, Sun's altitude and azimuth, and the event's position and vertex angles. The computer also reports the duration of the total phase, the duration of the eclipse, the magnitude of the eclipse, and the percent of the Sun obscured for a particular eclipse site. On-line documentation for using the API-enabled Solar Eclipse Computer, including sample calls, is available (http://aa.usno.navy.mil/data/docs/api.php). The same Web page also describes how to reach the Complete Sun and Moon Data for One Day, Phases of the Moon, Day and Night Across the Earth, and Apparent Disk of a Solar System Object services using API calls.For those who prefer using a traditional data input form, local circumstances can still be requested that way at http://aa.usno.navy.mil/data/docs/SolarEclipses.php. In addition, the 2017 August 21 Solar Eclipse Resource page (http://aa.usno.navy.mil/data/docs/Eclipse2017.php) consolidates all of the USNO resources for this event, including a Google Map view of the eclipse track designed by Her Majesty's Nautical Almanac Office (HMNAO). Looking further ahead, a

  8. Influence of solar eclipse of November 3rd, 2013 on the total ozone column over Badajoz, Spain

    CERN Document Server

    Mateos, D; Vaquero, J M

    2014-01-01

    The hybrid eclipse of November 3rd, 2013 was observed as partial with a magnitude equal to 0.126 from Badajoz (38^\\circ 53' N, 6^\\circ 58' W). The evolution of the Total Ozone Column (TOC) values during 4 hours was monitored using a Solar Light Microtops-II manual sun-photometer. Before the eclipse, TOC remained invariable ~280 Dobson Units (DU) for one hour and a half. Once the eclipse was started, a clear decrease in TOC occurred. After the eclipse maximum (with TOC = 273 DU), a rapid TOC recovery was observed. When the eclipse was over, TOC came back to values ~280 DU.

  9. Implementation of Bessel's method for solar eclipses prediction in the WRF-ARW model

    Science.gov (United States)

    Montornes, Alex; Codina, Bernat; Zack, John W.; Sola, Yolanda

    2016-05-01

    Solar eclipses are predictable astronomical events that abruptly reduce the incoming solar radiation into the Earth's atmosphere, which frequently results in non-negligible changes in meteorological fields. The meteorological impacts of these events have been analyzed in many studies since the late 1960s. The recent growth in the solar energy industry has greatly increased the interest in providing more detail in the modeling of solar radiation variations in numerical weather prediction (NWP) models for the use in solar resource assessment and forecasting applications. The significant impact of the recent partial and total solar eclipses that occurred in the USA (23 October 2014) and Europe (20 March 2015) on solar power generation have provided additional motivation and interest for including these astronomical events in the current solar parameterizations.Although some studies added solar eclipse episodes within NWP codes in the 1990s and 2000s, they used eclipse parameterizations designed for a particular case study. In contrast to these earlier implementations, this paper documents a new package for the Weather Research and Forecasting-Advanced Research WRF (WRF-ARW) model that can simulate any partial, total or hybrid solar eclipse for the period 1950 to 2050 and is also extensible to a longer period. The algorithm analytically computes the trajectory of the Moon's shadow and the degree of obscuration of the solar disk at each grid point of the domain based on Bessel's method and the Five Millennium Catalog of Solar Eclipses provided by NASA, with a negligible computational time. Then, the incoming radiation is modified accordingly at each grid point of the domain.This contribution is divided in three parts. First, the implementation of Bessel's method is validated for solar eclipses in the period 1950-2050, by comparing the shadow trajectory with values provided by NASA. Latitude and longitude are determined with a bias lower than 5 x 10-3 degrees (i

  10. Eclipse burns: a prospective study of solar retinopathy following the 1999 solar eclipse.

    Science.gov (United States)

    Wong, S C; Eke, T; Ziakas, N G

    2001-01-20

    Looking at the sun can cause focal burns to the retina. We prospectively followed up all patients who presented to Eye Casualty of Leicester Royal Infirmary having observed the solar eclipse of August, 1999. 45 patients attended, of whom 20 had visual symptoms and five had visible changes in the retina; four patients were still symptomatic after 7 months.

  11. Solar eclipse effect on geomagnetic induction parameters

    Directory of Open Access Journals (Sweden)

    A. Ádám

    2005-12-01

    Full Text Available The 11 August 1999 total solar eclipse had been studied using a large array of stations in Central Europe (Bencze et al., 2005. According to the result of this study, the amplitudes of the field line resonance (FLR-type pulsations decreased in and around the dark spot by about a factor of 2, and this decrease moved with the velocity of the dark spot in the same direction. This decrease was interpreted as a switch-off of the FLR-type pulsations, due to a change in the eigenperiod of the field line as a consequence of a change in the charged particle distribution along the field line. An effect was also found in the phase of the (magnetic or electric perpendicular components.

    At the Nagycenk (NCK observatory lying in the zone of totality, both magnetic and electric records were available. The magnetotelluric (MT sounding curve computed by the usual method for the eclipse interval (08:00-14:00 UT fits the previously known standard curve extremely well. During the eclipse, however, impedance values in the FLR period range were highly scattered. The scatter remained as long as the eclipse lasted. Coherence values between magnetic and electric components decreased significantly. In contrast, an earlier similar switch-off of the FLR-type activity on the same day did not cause a similar scatter, in spite of a comparably low coherence. Thus, the lack of FLR-type activity disturbed the usual MT connection between the magnetic and electric components during the eclipse.

    The induction vector (tipper, especially its real part, shows a clear effect of the eclipse in the FLR period range (24-29 s, too. Both at NCK and at Bad Bergzabern (BBZ, westernmost station and longest FLR period, a definite decrease in the real tipper was ascertained during the totality. The average direction of the tipper did not change.

    Concerning both parameters, a random effect cannot fully

  12. Capsicum Annuum L. Midnight Creeper and Solar Eclipse

    Science.gov (United States)

    The USDA, ARS announces the release of two new pepper cultivars 06C84 (trademarked as Midnight Creeper) and 07C114-1 (trademarked as Solar Eclipse). Midnight Creeper and Solar Eclipse are intended for ornamental applications. Midnight Creeper’s prostrate spreading indeterminate growth habit, black f...

  13. Numerical Modeling of Equatorial Electrojet Behavior During April, 8, 2005 Solar Eclipse

    Science.gov (United States)

    Klimenko, M. V.; Klimenko, V. V.; Bryukhanov, V. V.

    2007-05-01

    In the given work the results of numerical calculations of global distribution of potential of electric field and linear density of zonal current in the ionosphere of the Earth during a solar eclipse are presented. Calculations have been executed on the basis of Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP), developed in WD IZMIRAN, added by the new block of calculation of electric fields in the ionosphere of the Earth. In calculations we considered superposition of magnetospheric convection electric field and dynamo field generated by thermospheric winds without taking into account the tides. The solar eclipse of hybrid type viewed in the given work has occurred on April, 8, 2005. The hybrid eclipse was visible from within a thin corridor, which traverses the Southern Hemisphere. The path of the shadow of the Moon has begun southeast of New Zealand and stretched across the Pacific Ocean to Panama, Columbia, and Venezuela. The eclipse has begun at 18.54 UT and has ended at 22.15 UT. From 20.30 UT till 21.10 UT the shadow of an eclipse transited in a neighborhood of geomagnetic equator. It is shown, that the solar eclipse caused impairment of equatorial electrojet intensity twice. First time it has occurred at the initial stage of the eclipse due to change in ionosphere conductivity in the region of influence of field aligned currents. It has led to change of distribution of magnetospheric convection electric field (18.58 UT - 19.06 UT). Second time it has occurred during the passage of a solar eclipse through geomagnetic equator with delay of 30 min (21.00 UT - 21.20 UT) due to local changes of ionospheric conductivity in the region of the eclipse and reorganization of thermospheric circulation to which the time delay is related. It has led to change of distribution of dynamo field in the region of geomagnetic equator.

  14. Solar Diameter Measurements from Eclipses as a Solar Variability Proxy

    Science.gov (United States)

    Waring Dunham, David; Sofia, Sabatino; Guhl, Konrad; Herald, David Russell

    2015-08-01

    Since thermal relaxation times for the Sun are thousands of years, small variations of the Solar intensity are proportional to small variations of the Solar diameter on decadal time scales. In a combination between observations and theory, reliable values of the relation constant W are known, that allow transformation of historical variations of radius into variations of the solar luminosity. During the past 45 years, members of the International Occultation Timing Association (IOTA) have observed 20 annular and total solar eclipses from locations near the path edges. Baily’s beads, whose occurrence and duration are considerably prolonged as seen from path edge locations, were first timed visually, mostly using projection techniques, but since about 1980, they have been timed mainly from analysis of video recordings. The edge locations have the advantage that most of the beads are defined by the same features in the lunar polar regions that cause the phenomena at each eclipse. Some of the best-observed modern eclipses can be used to assess the accuracy of the results, which are limited mainly by the intensity drop at the Sun’s edge, and the consequent uncertainty in defining the edge. In addition, direct visual contact timings made near the path edges during earlier eclipses, back to 1715, have been found in the literature, and analyzed. Although the observations seem to show small variations, they are only a little larger than the assessed accuracies. The results can be improved with a consistent re-analysis of the observations using the much more accurate lunar profile data that is now available from the Japanese Kaguya and NASA’s LRO lunar orbiter observations. Also, IOTA has plans to observe future eclipses with a variety of techniques that were used in the past, to better assess the accuracies of the different observational methods that have been used, and determine any systematic differences between them.

  15. First Results from the August 21, 2017, Total Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay M.

    2017-08-01

    I report on the observations planned and, weather permitting, made from our site in Salem, Oregon, at the August 21, 2017, total solar eclipse. I also give a first report on collaborators' successes, including Megamovie and simultaneous space observations. We also describe our participation in PBS's NOVA on the eclipse that was to be aired on public television on eclipse night. Our eclipse expedition is supported in large part by grants from the Solar Terrestrial Program of the Atmospheric Sciences Division of NSF and by the Committee for Research and Exploration of the National Geographic Society.

  16. Gravity Effects of Solar Eclipse and Inducted Gravitational Field

    Science.gov (United States)

    Tang, K.; Wang, Q.; Zhang, H.; Hua, C.; Peng, F.; Hu, K.

    2003-12-01

    During solar eclipses in recent decades, gravity anomalies were observed and difficult to be explained by Newton's gravitational theory. During the solar eclipse of 1995, India scientists Mishra et al. recorded a gravity valley in amplitude of 12 μ Gal; they interpreted that qualitatively as atmospheric effects. During the total solar eclipse of March 1997, we conducted a comprehensive geophysical observation at Mohe geophysical observatory of China (with latitude of 53.490 N and longitude of 122.340 E. From the data we recorded, we found two valleys about 5 to 7 μ Gal. Unnikrishnan et al. inferred this gravity anomaly was caused by the environment changes. We know that the observation had been conducting in a room inside a small building with a stable coal heating system; the temperature variation inside the experimental room was less 10C during the eclipse. Moreover, the measured atmospheric pressure change was less 1hPa during the eclipse. It is reasonable to believe that surrounding environment of the observatory excluded the significant gravity variations caused by temperature, pressure variation and local moving of persons and vehicles. To further study the gravity effects related to solar eclipses, our scientific team took more observations during Zambia total solar eclipse of June 2001 and Australia total solar eclipse of December 2002. After data corrections, we found respectively two gravity anomalies, with 3 to 4μ Gal for Zambia eclipse and 1.5μ Gal for Australia eclipse. As many scientists have pointed out that pressure-gravity factor is lower than 0.3μ Gal/hPa, it means that any gravity anomaly great than 0.5μ Gal could not be inferred as the results of atmospheric pressure change. The two more gravity anomalies recorded during the solar eclipses provided us strong evidences that some gravity anomalies could not simply be inferred as atmospheric pressure change. We have tried to explain those anomalies by the induced gravitational field.

  17. Educating the Public about the 2017 Total Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay M.

    2017-01-01

    On behalf of the International Astronomical Union's Working Group on Solar Eclipses, I have long worked to bring knowledge about eclipses and how to observe the safely to the people of the various countries from which partial, annular, or total solar eclipses are visible. In 2017, we have first a chance to educate the people of South America on the occasion of the February 26 annular eclipse through southern Chile and Argentina that is partial throughout almost the entire continent (and an eclipse workshop will be held February 22-24 in Esquel, Argentina: http://sion.frm.utn.edu.ar/WDEAII) and then a chance to educate the 300 million people of the United States and others in adjacent countries as far south as northern South America about the glories of totality and how to observe partial phases. Our website, a compendium of links to information about maps, safe observing, science, and more is at http://eclipses.info. We link to important mapping sites at EclipseWise.com, GreatAmericanEclipse.com, and http://xjubier.free.fr/en/site_pages/solar_eclipses/xSE_GoogleMap3.php?Ecl=+20170821&Acc=2&Umb=1&Lmt=1&Mag=1&Max=1, and information about cloudiness statistics at http://eclipsophile.com, as well as simulation sites at https://svs.gsfc.nasa.gov/cgi-bin/details.cgi?aid=4314 and http://eyes.jpl.nasa.gov. The American Astronomical Society's task force on the 2017 eclipse has a website at http://eclipse.aas.org. We are working to disseminate accurate information about how and why to observe the total solar eclipse, trying among other things to head off common misinformation about the hazards of looking at the sun at eclipses or otherwise. About 12 million Americans live within the 70-mile-wide band of totality, and we encourage others to travel into it, trying to make clear the difference between even a 99% partial eclipse and a total eclipse, with its glorious Baily's beads, diamond rings, and totality that on this occasion lasts between 2 minutes and 2 minutes 40 seconds

  18. Solar Eclipses and the International Year of Astronomy

    Science.gov (United States)

    Pasachoff, Jay M.

    2009-05-01

    Solar eclipses capture the attention of millions of people in the countries from which they are visible and provide a major opportunity for public education, in addition to the scientific research and student training that they provide. The 2009 International Year of Astronomy began with an annular eclipse visible from Indonesia on 26 January, with partial phases visible also in other parts of southeast Asia. On 22 July, a major and unusually long total solar eclipse will begin at dawn in India and travel across China, with almost six minutes of totality visible near Shanghai and somewhat more visible from Japanese islands and from ships at sea in the Pacific. Partial phases will be visible from most of eastern Asia, from mid-Sumatra and Borneo northward to mid-Siberia. Eclipse activities include many scientific expeditions and much ecotourism to Shanghai, Hangzhou, and vicinity. My review article on "Eclipses as an Astrophysical Laboratory" will appear in Nature as part of their IYA coverage. Our planetarium presented teacher workshops and we made a film about solar research. Several new books about the corona or eclipses are appearing or have appeared. Many articles are appearing in astronomy magazines and other outlets. Eclipse interviews are appearing on the Planetary Society's podcast "365 Days of Astronomy" and on National Geographic Radio. Information about the eclipse and safe observation of the partial phases are available at http://www.eclipses.info, the Website of the International Astronomical Union's Working Group on Solar Eclipses and of its Program Group on Public Education at the Times of Eclipses of its Commission on Education and Development. The Williams College Expedition to the 2009 Eclipse in the mountains near Hangzhou, China, is supported in part by a grant from the Committee for Research and Exploration of the National Geographic Society. E/PO workshops were supported by NASA.

  19. Fifteen years of solar eclipses - 1986-2000

    Science.gov (United States)

    Espenak, Fred

    1986-01-01

    The dates of occurrence and the paths of observability of the three total eclipses and 30 partial eclipses of the sun which will occur over the period 1986-2000 AD are identified. Data are provided for the times and duration of local maxima, the extent of coverage of the solar disk, and the breadth of the footprint of the eclipses on the earth's surface.

  20. Coronal Dynamics at Recent Total Solar Eclipses

    Science.gov (United States)

    Pasachoff, J. M.; Lu, M.; Davis, A. B.; Demianski, M.; Rusin, V.; Saniga, M.; Seaton, D. B.; Lucas, R.; Babcock, B. A.; Dantowitz, R.; Gaintatzis, P.; Seeger, C. H.; Malamut, C.; Steele, A.

    2014-12-01

    Our composite images of the solar corona based on extensive imaging at the total solar eclipses of 2010 (Easter Island), 2012 (Australia), and 2013 (Gabon) reveal several coronal mass ejections and other changes in coronal streamers and in polar plumes. Our resultant spatial resolution is finer than that available in imaging from spacecraft, including that from SOHO/LASCO or STEREO. We trace the eruptions back to their footpoints on the sun using imaging from SDO and SWAP, and follow them upwards through the corona, measuring velocities. The high-resolution computer compositing by Miloslav Druckmüller and Hana Druckmüllerová (2010 and 2013) and Pavlos Gaintatzis (2012) allows comparison of our images with those taken at intervals of minutes or hours along the totality path. Williams College's 2013 eclipse expedition was supported in part by grant 9327-13 from National Geographic Society/Committee for Research and Exploration. Our work on the 2012 eclipse is supported in part by grant AGS-1047726 from Solar Terrestrial Research/NSF AGS. V.R. and M.S. were partially supported by the VEGA grant agency project 2/0098/10 and 2/0003/13 (Slovak Academy of Sciences) and Grant 0139-12 from NG/CRE, and Hana Druckmüllerová by grant 205/09/1469 of the Czech Science Foundation. M.L. was supported by Sigma Xi. C.M. was a Keck Northeast Astronomy Consortium Summer Fellow, supported at Williams College by REU/NSF grant AST-1005024. Partial support was provided by U.S. Department of Defense's ASSURE program. J.M.P. thanks Caltech's Planetary Sciences Department for hospitality. Support for D.B.S. and SWAP came from PRODEX grant C90345 managed by ESA in collaboration with the Belgian Federal Science Policy Office (BELSPO) in support of the PROBA2/SWAP mission, and from the EC's Seventh Framework Programme (FP7/2007-2013) under grant 218816 (SOTERIA project, www.soteria-space.eu). SWAP is a project of the Centre Spatial de Liège and the Royal Observatory of Belgium funded by

  1. A Smoothed Eclipse Model for Solar Electric Propulsion Trajectory Optimization

    Science.gov (United States)

    Aziz, Jonathan; Scheeres, Daniel; Parker, Jeffrey; Englander, Jacob

    2017-01-01

    Solar electric propulsion (SEP) is the dominant design option for employing low-thrust propulsion on a space mission. Spacecraft solar arrays power the SEP system but are subject to blackout periods during solar eclipse conditions. Discontinuity in power available to the spacecraft must be accounted for in trajectory optimization, but gradient-based methods require a differentiable power model. This work presents a power model that smooths the eclipse transition from total eclipse to total sunlight with a logistic function. Example trajectories are computed with differential dynamic programming, a second-order gradient-based method.

  2. Influence of solar eclipse of November 3rd, 2013 on the total ozone column over Badajoz, Spain

    OpenAIRE

    Mateos, D.; M. Antón; Vaquero, J. M.

    2014-01-01

    The hybrid eclipse of November 3rd, 2013 was observed as partial with a magnitude equal to 0.126 from Badajoz (38^\\circ 53' N, 6^\\circ 58' W). The evolution of the Total Ozone Column (TOC) values during 4 hours was monitored using a Solar Light Microtops-II manual sun-photometer. Before the eclipse, TOC remained invariable ~280 Dobson Units (DU) for one hour and a half. Once the eclipse was started, a clear decrease in TOC occurred. After the eclipse maximum (with TOC = 273 DU), a rapid TOC r...

  3. [Unilateral Solar Maculopathy after Gazing at Solar Eclipse].

    Science.gov (United States)

    Mehlan, J; Linke, S J; Wagenfeld, L; Steinberg, J

    2016-06-01

    A 43-year-old male patient with unilateral metamorphosia presented after gazing at an eclipse with only one eye. Damage of the macula was demonstrated funduscopically, with OCT and angiography. Six weeks after initial presentation and oral methylprednisolone therapy (40 mg/d for 10 days), the symptoms and the morphological changes decreased. Solar retinopathy is a photochemical alteration of the retina, usually seen after sun gazing. In younger patients, it mostly presents as bilateral solar maculopathy. Some patients exhibit partial or total recovery.

  4. The 2017 Total Solar Eclipse: Through the Eyes of NASA

    Science.gov (United States)

    Young, C. Alex; Mayo, Louis; Ng, Carolyn; Cline, Troy; Lewis, Elaine; Reed, Shannon; Debebe, Asidesach; Stephenson, Bryan; Odenwald, Sten; Hill, Steele; Wright, Ernest

    2017-01-01

    The August 21, 2017 eclipse will be the first time a total solar eclipse has traversed the Continental US since June 8th, 1918. Anticipation and energy for this eclipse is off the charts! Over 500 million in North America alone will catch the eclipse in either partial or total phase. Parts of South America, Africa, and Europe will see a partial eclipse as well. NASA is planning to take full advantage of this unique celestial event as an education and public engagement opportunity by leveraging its extensive networks of partners, numerous social media platforms, broadcast media, and its significant unique space assets and people to bring the eclipse to America and the world as only NASA can.This talk will outline NASA’s education plans in some detail replicating our many Big Events successes including the 2012 Transit of Venus and the MSL/Curiosity landing and show how scientists and the public can get involved.

  5. Solar (superíndice) 2, remisión de V. eclipse solar.

    OpenAIRE

    2011-01-01

    [ES] Definición del término Solar (superíndice) 2, remisión de V. eclipse solar. en el diccionario Dicter. [EN] Definition of the word Solar (superíndice) 2, remisión de V. eclipse solar. in the dictionary Dicter.

  6. Results from and Plans for the Two 2017 Solar Eclipses

    Science.gov (United States)

    Pasachoff, Jay M.; Seaton, Daniel; Kentrianakis, Michael; Fischer, Daniel

    2017-06-01

    At this writing fresh from observing the 26 February 2017 annular solar eclipse in exceptionally clear sky from sites in Patagonia, Argentina, we show images from the centerline near Facundo showing Baily's beads and central annularity of the magnitude 99.3% eclipse. From close to the edge of the path from sites north of Facundo within the northern limit (images by Daniel Fischer) and north of Sarmiento at the southern limit (images by Jörg Schoppmeyer), we show unfiltered images that show substantial solar chromosphere with innermost corona above it. We also show SWAP and SDO eclipse images.For the 21 August 2017 total solar eclipse, we describe our plans for observing coronal structure above the limb from the ground in Oregon and for ultraviolet imaging on the solar disk at the time of the terrestrial eclipse through six filters using the new Solar Ultraviolet Imager (SUVI) on the National Oceanic and Atmospheric Administration's GOES-16 spacecraft, planned along with three similar spacecraft for coronal coverage for the next two decades. SUVI has the biggest overlapping field of view, 53 arcmin square, of any multi-channel space-based EUV imager.Our research on the 2017 total solar eclipse is supported by grants from the Committee for Research and Exploration of the National Geographic Society and from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation. NOAA NCEI are the acronyms for the National Oceanic and Atmospheric Administration's National Centers for Environmental Information.

  7. Science Experimenter: Observing the Sun and Solar Eclipses.

    Science.gov (United States)

    Mims, Forrest M., III

    1991-01-01

    Describes the construction and use of simple optical aids that allow the amateur scientist to safely observe sunspots and solar eclipses and also to measure the sun's rotation. (five references) (JJK)

  8. Visual damage following direct sighting of solar eclipse in Ghana ...

    African Journals Online (AJOL)

    Visual damage following direct sighting of solar eclipse in Ghana. ... Abstract. A study was carried out at the department of Ophthalmology and ... assessment of Visual Acuity (VA), Slit Lamp examination, Fundoscopy, Amsle Test, Intra-ocular ...

  9. Public Education and Outreach for Observing Solar Eclipses and Transits

    Science.gov (United States)

    Pasachoff, Jay M.

    2015-08-01

    The general public is often very interested in observing solar eclipses, with widespread attention from newspapers and other sources often available only days before the events. Recently, the 2012 eclipse's partial phases in Australia and the 2015 eclipse's partial phases throughout Europe as well as western Asia and northern Africa, were widely viewed. The 21 August 2017 eclipse, whose totality will sweep across the Continental United States from northwest to southeast, will have partial phases visible throughout the U.S., Canada, Mexico, Central America, and into South America. The 2019 and 2020 partial phases of total eclipses will be visible throughout South America, and partial phases from annular eclipses will be visible from other parts of the world. The 9 May 2016 transit of Mercury will be best visible from the Western Hemisphere, Europe, and Africa. Many myths and misunderstandings exist about the safety of observing partial phases, and it is our responsibility as astronomers and educators to transmit accurate information and to attempt the widest possible distribution of such information. The Working Group on Public Education at Eclipses and Transits, formerly of Commission 46 on Education and Development and now of New Commission 11, tries to coordinate the distribution of information. In collaboration with the Solar Division's Working Group on Solar Eclipses, their website at http://eclipses.info is a one-stop shop for accurate information on how to observe eclipses, why it is interesting to do so, where they will be visible (with links to online maps and weather statistics), and how encouraging students to observe eclipses can be inspirational for them, perhaps even leading them to realize that the Universe can be understood and therefore renewing the strength of their studies. Links to information about transits of Mercury and Venus are also included.

  10. Theoretical and observational problems related to solar eclipses. Proceedings.

    Science.gov (United States)

    Mouradian, Z.; Stavinschi, M.

    The contributions to this book are based on the current knowledge of solar corona physics and on the prospects for future total eclipse observations, focusing on the eclipse of August 11, 1999, which forecasters believe will occur at precisely the maximum of solar activity. The results of past eclipse observations are reviewed, including coronal hot and cold structures, coronal heating, public education and instrumental problems. The relation of the corona to the Sun is discussed, viz., the energy and mass transfer between the chromosphere and the corona, including the formation of prominences by coronal condensation in coronal cavities and the supply of mass to the corona by spicules.

  11. Search for radiative decays of solar neutrinos during a solar eclipse

    CERN Document Server

    Giacomelli, G

    2001-01-01

    A search for possible radiative decays of solar neutrinos with emission of photons in the visible range may be performed during total solar eclipses. We discuss some results obtained from the digitized images recorded during the August 11, 1999 total solar eclipse in Romania, and report on the observations made in June 21, 2001, in Zambia.

  12. Mach bands change asymmetrically during solar eclipses.

    Science.gov (United States)

    Ross, John; Diamond, Mark R; Badcock, David R

    2003-01-01

    Observations made during two partial eclipses of the Sun show that the Mach bands on shadows cast by the Sun disappear and reappear asymmetrically as an eclipse progresses. These changes can be explained as due to changes in the shape of the penumbras of shadows as the visible portion of the Sun forms crescents of different orientation.

  13. Total Solar Eclipse of 2002 December 04

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    2001-01-01

    On 2002 December 04, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Southern Hemisphere. The path of the Moon's umbral shadow begins in the South Atlantic, crosses southern Africa and the Indian Ocean, and ends at sunset in southern Australia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the southern two thirds of Africa, Antarctica, Indian Ocean and Australia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 400 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  14. Total Solar Eclipse of 2008 August 01

    Science.gov (United States)

    Espenak, F.; Anderson, J.

    2007-01-01

    On 2008 August 01, a total eclipse of the Sun is visible from within a narrow corridor that traverses half the Earth. The path of the Moon's umbral shadow begins in northern Canada and extends across Greenland, the Arctic, central Russia, Mongolia, and China. A partial eclipse is seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, most of Europe and Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 308 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  15. Total Solar Eclipse of 2006 March 29

    Science.gov (United States)

    Espenak, F.; Anderson, J.

    2004-01-01

    On 2006 March 29, a total eclipse of the Sun will be visible from within a narrow corridor which traverses half the Earth. The path of the Moon's umbral shadow begins in Brazil and extends across the Atlantic, northern Africa, and central Asia where it ends at sunset in western Mongolia. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes the northern two thirds of Africa, Europe, and central Asia.Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Information on safe eclipse viewing and eclipse photography is included.

  16. The Total Solar Eclipse of March 2006: overview

    Directory of Open Access Journals (Sweden)

    E. Gerasopoulos

    2007-12-01

    Full Text Available This paper provides an overview of integrated, multi-disciplinary effort to study the effects of a total solar eclipse on the environment, with special focus on the atmosphere. On the occasion of the 29 March 2006 total solar eclipse, visible over the Eastern Mediterranean, several research and academic institutes organised co-ordinated experimental campaigns, at different distances from the totality and in various environments in terms of air quality. The detailed results are presented in a number of scientific papers included in a Special Issue of Atmospheric Chemistry and Physics. The effects of the eclipse on the meteorology and the spectral solar radiation, the chemical response of the atmosphere to the abrupt "switch off" of the sun and the induced changes in the stratosphere and the ionosphere, have been among the issues covered. The rare event of a total solar eclipse provided the opportunity to evaluate 1-D and 3-D radiative transfer models (in the atmosphere and underwater, mesoscale meteorological, regional air quality and photochemical box models, against measurements. Within the challenging topics of this effort has been the investigation of eclipse impacts on ecosystems (field crops and marine plankton and the identification of eclipse induced gravity waves, for the first time with simultaneous measurements at three altitudes namely the troposphere, the stratosphere and the ionosphere.

  17. [Solar Maculopathy after Watching the Partial Solar Eclipse].

    Science.gov (United States)

    Kristian, P; Timkovič, J; Cholevík, D; Dedek, V

    2015-09-01

    To describe clinical findings in patients with sudden decrease of visual functions according to the solar maculopathy appearance after watching the partial solar eclipse and results of the changes follow-up after 7 weeks. Medical records of five women (6 eyes) with solar maculopathy associated with watching partial solar eclipse on March 20th, 2015 were retrospectively evaluated. The diagnosis of solar maculopathy was established according to the medical history, ophthalmologic examination of the fundus in artificial mydriasis, and confirmed by means of spectral domain optic coherence tomography examination of the macula. The follow-up period of the patients in the study group was 7 weeks. All patients described the presence of relative central scotoma and decrease of the central visual acuity (VA) of different extension in the involved eye. The average best-corrected visual acuity (BCVA) of women in our group was 6/9 (range, 6/6 partially - 6/18). In one patient, the involvement was bilateral, in the other cases the involvement was unilateral. The biomicroscopic examination of the fundus revealed yellowish to yellow-whitish lesions with brightness of the pigment layer in the center of the foveola in all patients. The optic coherence tomography examination of the macula confirmed the irregularities of the retinal pigment layer and photoreceptors outer segment with hyper-reflective focus of the neuroretina in the center of the foveola. During the follow-up period, we recorded improvement of the central visual acuity in all women with unilateral involvement. In the woman with bilateral retinal involvement, the best-corrected visual acuity of the right eye remains without any improvement. The optic coherence tomography examination after 7 weeks shows regression of the findings in three eyes. In all other cases, slight structural changes in the center of the macula persist.

  18. 20 March 2015 solar eclipse influence on sporadic E layer

    Science.gov (United States)

    Pezzopane, M.; Pietrella, M.; Pignalberi, A.; Tozzi, R.

    2015-11-01

    This paper shows how the solar eclipse occurred on 20 March 2015 influenced the sporadic E (Es) layer as recorded by the Advanced Ionospheric Sounder by Istituto Nazionale di Geofisica e Vulcanologia (AIS-INGV) ionosondes installed at Rome (41.8°N, 12.5°E) and Gibilmanna (37.9°N, 14.0°E), Italy. In these locations, the solar eclipse was only partial, with the maximum area of the solar disk obscured by the Moon equal to ∼54% at Rome and ∼45% at Gibilmanna. Nevertheless, it is shown that the strong thermal gradients that usually accompany a solar eclipse, have significantly influenced the Es phenomenology. Specifically, the solar eclipse did not affect the Es layer in terms of its maximum intensity, which is comparable with that of the previous and next day, but rather in terms of its persistence. In fact, both at Rome and Gibilmanna, contrary to what typically happens in March, the Es layer around the solar eclipse time is always present. On the other hand, this persistence is also confirmed by the application of the height-time-intensity (HTI) technique. A detailed analysis of isoheight ionogram plots suggests that traveling ionospheric disturbances (TIDs) likely caused by gravity wave (GW) propagation have played a significant role in causing the persistence of the Es layer.

  19. MOC Views of Martian Solar Eclipses

    Science.gov (United States)

    1999-01-01

    [figure removed for brevity, see original site] The shadow of the martian moon, Phobos, has been captured in many recent wide angle camera views of the red planet obtained by the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC). Designed to monitor changes in weather and surface conditions, the wide angle cameras are also proving to be a good way to spot the frequent solar eclipses caused by the passage of Phobos between Mars and the Sun.The first figure (above), shows wide angle red (left), blue (middle), and color composite (right) views of the shadow of Phobos (elliptical feature at center of each frame) as it was cast upon western Xanthe Terra on August 26, 1999, at about 2 p.m.local time on Mars. The image covers an area about 250 kilometers (155 miles) across and is illuminated from the left. The meandering Nanedi Valles is visible in the lower right corner of the scene. Note the dark spots on three crater floors--these appear dark in the red camera image (left) but are barely distinguished in the blue image (middle), while the shadow is dark in both images. The spots on the crater floors are probably small fields of dark sand dunes.The second figure shows three samples of MOC's global image swaths, each in this case with a shadow of Phobos visible (arrow). The first scene (left) was taken on September 1, 1999, and shows the shadow of Phobos cast upon southern Elysium Planitia. The large crater with dark markings on its floor at the lower right corner is Herschel Basin. The second scene shows the shadow of Phobos cast upon northern Lunae Planum on September 8, 1999. Kasei Valles dominates the upper right and the deep chasms of Valles Marineris dominate the lower third of the September 8 image. The picture on the right shows the shadow of Phobos near the giant volcano, Olympus Mons (upper left), on September 25, 1999. Three other major volcanoes are visible from lower-center (Arsia Mons) and right-center (Pavonis Mons) to upper-middle-right (Ascraeus Mons

  20. Solar radiation measurements from coordinated radiosonde flights during the 20th March 2015 solar eclipse

    Science.gov (United States)

    Harrison, R. Giles; Marlton, Graeme; Williams, Paul; Nicoll, Keri

    2016-04-01

    Solar radiation sensors can be carried on standard weather balloon packages and provide additional information about the atmosphere's vertical structure beyond the traditional thermodynamic measurements [1]. An interesting set of circumstances for such sensors occurs during a solar eclipse, which provides a rapidly changing solar radiation environment within the duration of a typical free balloon flight. Coordinating several launches of solar radiation measuring radiosondes brings a good likelihood of at least one being above any cloud during the maximum eclipse, allowing solar eclipse radiation measurements for comparison with theory. For the 20th March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44N, 0.94W), Lerwick (60.15N, 1.13W) and Reykjavik (64.13N, 21.90W), straddling the path of the eclipse. All three balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. These approaches, which are essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes. [1] K.A. Nicoll and R.G. Harrison, Balloon-borne disposable radiometer Rev Sci Instrum 83, 025111 (2012) doi: 10.1063/1.3685252

  1. Total Solar Eclipse of 1997 March 9

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    1995-01-01

    A total eclipse of the Sun will be visible from Asia and the Pacific Ocean on 1997 March 9. The path of the Moon's umbral shadow begins in eastern Kazakhstan and travels through Mongolia and eastern Siberia, where it swings northward to end at sunset in the Arctic Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern Asia, the northern Pacific, and the northwest corner of North America. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 280 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  2. Total Solar Eclipse of 2001 June 21

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    1999-01-01

    On 2001 June 21, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Southern Hemisphere. The path of the Moon's umbral shadow begins in the South Atlantic, crosses southern Africa and Madagascar, and ends at sunset in the Indian Ocean. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes eastern South America and the southern two thirds of Africa. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 350 cities, maps of the eclipse path, weather prospects, the lunar limb profile and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  3. Total Solar Eclipse of 1999 August 11

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    1997-01-01

    On 1999 August 11, a total eclipse of the Sun will be visible from within a narrow corridor which traverses the Eastern Hemisphere. The path of the Moon's umbral shadow begins in the Atlantic and crosses central Europe, the Middle East, and India, where it ends at sunset in the Bay of Bengal. A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes northeastern North America, all of Europe, northern Africa, and the western half of Asia. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for approximately 1400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality. Tips and suggestions are also given on how to safely view and photograph the eclipse.

  4. Total solar eclipse of 3 November 1994

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    1993-01-01

    A total eclipse of the Sun will be visible from the southern half of the Western Hemisphere on 3 November 1994. The path of the Moon's shadow passes through Peru, Chile, Bolivia, Paraguay, and Brazil. Detailed predictions for this event are presented and include tables of geographic coordinates of the path of totality, local circumstances for hundreds of cities, maps of the path of total and partial eclipse, weather prospects, and the lunar limb profile.

  5. Solar eclipses as an astrophysical laboratory.

    Science.gov (United States)

    Pasachoff, Jay M

    2009-06-11

    Observations of the Sun during total eclipses have led to major discoveries, such as the existence of helium (from its spectrum), the high temperature of the corona (though the reason for the high temperature remains controversial), and the role of magnetic fields in injecting energy into-and trapping ionized gases within-stellar atmospheres. A new generation of ground-based eclipse observations reaches spatial, temporal and spectral-resolution domains that are inaccessible from space and therefore complement satellite studies.

  6. The total solar eclipse of March 2006: overview

    Directory of Open Access Journals (Sweden)

    A. Karamanos

    2008-09-01

    Full Text Available This paper provides the overview of an integrated, multi-disciplinary effort to study the effects of the 29 March 2006 total solar eclipse on the environment, with special focus on the atmosphere. The eclipse has been visible over the Eastern Mediterranean, and on this occasion several research and academic institutes organised co-ordinated experimental campaigns, at different distances from eclipse totality and at various environments in terms of air quality. Detailed results and findings are presented in a number of component scientific papers included in a Special Issue of Atmospheric Chemistry and Physics. The effects of the eclipse on meteorological parameters, though very clear, were shown to be controlled by local factors rather than the eclipse magnitudes, and the turbulence activity near surface was suppressed causing a decrease in the Planetary Boundary Layer. In addition to the above, the decrease in solar radiation has caused change to the photochemistry of the atmosphere, with night time chemistry dominating. The abrupt "switch off" of the sun, induced changes also in the ionosphere (140 up to 220 km and the stratosphere. In the ionosphere, both photochemistry and dynamics resulted to changes in the reflection heights and the electron concentrations. Among the most important scientific findings from the experiments undertaken has been the experimental proof of eclipse induced thermal fluctuations in the ozone layer (Gravity Waves, due to the supersonic movement of the moon's shadow, for the first time with simultaneous measurements at three altitudes namely the troposphere, the stratosphere and the ionosphere. Within the challenging topics of the experiments has been the investigation of eclipse impacts on ecosystems (field crops and marine plankton. The rare event of a total solar eclipse provided the opportunity to evaluate 1 dimensional (1-D and three dimensional (3-D radiative transfer (in the atmosphere and underwater

  7. Behavior of Photovoltaic System during Solar Eclipse in Prague

    Directory of Open Access Journals (Sweden)

    Martin Libra

    2016-01-01

    Full Text Available PV power plants have been recently installed in very large scale. So the effects of the solar eclipse are of big importance especially for grid connected photovoltaic (PV systems. There was a partial solar eclipse in Prague on 20th March 2015. We have evaluated the data from our facility in order to monitor the impact of this natural phenomenon on the behavior of PV system, and these results are presented in the paper. The behavior of PV system corresponds with the theoretical assumption. The power decrease of the PV array corresponds with the relative size of the solar eclipse. I-V characteristics of the PV panel correspond to the theoretical model presented in our previous work.

  8. Gravity anomaly during the Mohe total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By using a high-precision LaCoste-Romberg (1)-122#) gravimeter, continuous and precise measurements were carried out during the March 9, 1997 total solar eclipse in the Mohe region in Northeast China. The gravity variations were digitally recorded during the total solar eclipse so as to investigate the possible anomaly of the sun and the moon's gravitational fields on the earth. After the careful processing and analysis of the observed data, no significant anomaly during the very solar eclipse has been found. Howmetrical decrease of about 6- 7 μGal at the first contact and the last contact. This is the anomaly phenomenon observed and reported for the first time in the literature. This note presents some analyses and discussions.

  9. Study on geomagnetic effects of the March 9, 1997 solar eclipse in Mohe area, China*

    Institute of Scientific and Technical Information of China (English)

    冯忠孝; 高金田; 任熙宪

    2002-01-01

    The geomagnetic effects of the total solar eclipse in Mohe area and the partial eclipse occurred on March 9, 1997 in China are analyzed in this paper. The geomagnetic effects of the eclipse widely distributed in China are obtained, which show H component decreases obviously and is symmetric along the latitude with a center near 33(N during the eclipse time. These results of solar eclipse geomagnetic effects are the newest in recent years obtained in the largest area in China.

  10. In the Shadow of the Moon, What Type of Solar Eclipse Will We See?

    Science.gov (United States)

    Brown, Todd; Brown, Katrina

    2017-01-01

    Solar eclipses occur several times a year, but most people will be lucky if they see one total solar eclipse in their lifetime. There are two upcoming total solar eclipses that can be seen from different parts of the United States (August 21, 2017 and April 8, 2024), and they provide teachers with an amazing opportunity to engage students with a…

  11. The solar eclipse of 2017 where and how to best view it

    CERN Document Server

    Held, Wolfgang

    2015-01-01

    On Monday, August 21, 2017, there will be a solar eclipse of the sun visible from large parts of North America, from Oregon across to South Carolina. It will be the first total eclipse visible from mainland US since 1979, and there will not be a significant total eclipse in Europe until 2026. For many westerners, therefore, 2017 is the best opportunity for decades to view a solar eclipse.Preparation is key to successfully observing an eclipse. This guide to the 2017 eclipse tells you the best places and exact times to see the eclipse (including detailed maps), as well as lots of tips on the be

  12. Social Impact of Solar Eclipse in Indonesia: A Comparative Study

    Science.gov (United States)

    Mumpuni, Emanuel S.; Hidayat, Bambang

    2012-09-01

    The social impact and public comprehension of the natural phenomenon varies depending on how a particular cultural background perceives the phenomenon and how the interaction between general public and the authoritative bodies has persisted. While astronomers and scientists have taken for granted that solar eclipse is a natural phenomenon and subjected it to various scientific studies, large percentages of the population have been left uninformed scientifically and have responded to the phenomena quite differently. The technical and scientific aspects of the earliest expedition, to Padang (Sumatra) in 1901, have recently been discussed at length.Two major solar eclipses, namely the 1926 and 1929, offered many scientific outputs as well as results on observations of societies: anthropology, demography, and culinary habits of the local inhabitants. Those days, science was the preserve of a few selected. To a certain degree, many old perceptions of on natural phenomena, with their ruling deities still lingered on. The purpose of this paper is to show the changing views of the endogenous population in particular after the government's massive efforts to enlighten the people and to empower the younger generations in comprehending natural phenomena. The great efforts of the Government of Indonesia's Institute of Sciences (LIPI) related to the June 1983 solar eclipse produced a dramatic change in the sense of appreciation of solar eclipse as a natural phenomenon in consequence of relative motions of the Sun, Moon and the Earth. It took however another five years, till the time of the great eclipse in 1988, to a full fruition in which younger generations as well as older ones abandoned almost completely the old views and embarked on the understanding the value of solar eclipse for science.

  13. Tutulemma of near equator Partial Solar Eclipse 2016

    Science.gov (United States)

    Mumtahana, F.; Sartika; Admiranto, A. G.; Sungging, E.; Nurzaman, M. Z.; Priyatikanto, R.; Dani, T.

    2016-11-01

    Tutulemma which stands for tutulma (eclipse) and analemma is a Turkish name to describe analemma which contains solar eclipse. The photographs of analemma which looks like a figure 8 pattern of the solar path in the sky throughout a year is very common. However, this observation is rarely done in low latitude countries, especially tutulemma's plot. Related to the eclipse event on 9 March 2016, we built the first tutulemma in Indonesia which cointains partial solar eclipse observed from the rooftop of LAPAN Bandung office. The purpose of this endeavor is also to understand how the sun moves in one year, particularly at low latitude region based on observation data. We took the picture of the Sun every week at the same time of the day (the time of the eclipse). In this observation, we used a tripod and DSLR camera with a variable ND filter to take the data. To obtain the pattern, the weekly data were combined by image stacking using the same foreground. Finally, we got a figure 8 shaped pattern tutulemma which a bit different from high latitude country ones.

  14. Howard Russell Butler's Oil Paintings of Solar Eclipses and Prominences

    Science.gov (United States)

    Pasachoff, Jay M.; Olson, Roberta J. M.

    2014-06-01

    Howard Russell Butler (1856-1934) was invited to join the US Naval Observatory expedition to the total solar eclipse of 1918 because of his ability to paint astronomical phenomena based on quickly-made notes about spatial and color details. His giant triptych of the total eclipses of 1918, 1923, and 1925 was proposed for a never-built astronomical center at the American Museum of Natural History and wound up at their Hayden Planetarium when it was constructed in the mid-1930s. Half-size versions are installed at the Fels Planetarium at the Franklin Institute in Philadelphia and at the Firestone Library of Princeton University, whose newly conserved canvases were recently hung; the Buffalo Museum of Science has another half-size version in storage. We discuss not only the eclipse triptychs but also the series of large oil paintings he made of solar prominences (in storage at the American Museum of Natural History) and of his 1932-eclipse and other relevant works.JMP was supported for this work in part by Division III Discretionary Funds and the Brandi Fund of Williams College. His current eclipse research is supported by grants AGS-1047726 from the Solar Research Program of the Atmospheric and Geospace Sciences Division of NSF and 9327-13 from the Committee for Research and Exploration of the National Geographic Society.

  15. Eclipse Megamovie: Solar Discoveries, Education, and Outreach through Crowdsourcing 2017 Eclipse Images

    Science.gov (United States)

    Peticolas, L. M.; Hudson, H. S.; Martinez Oliveros, J. C.; Johnson, C.; Zevin, D.; Krista, L. D.; Bender, M.; Mcintosh, S. W.; Konerding, D.; Koh, J.; Pasachoff, J.; Lorimore, B.; Jiang, G.; Storksdieck, M.; Yan, D.; Shore, L.; Fraknoi, A.; Filippenko, A.

    2016-12-01

    Since 2011, a team of solar scientists, eclipse chasers, education and outreach professionals, and film makers have been working to explore the possibility of gathering images from the public during the 2017 eclipse across the United States, to be used for scientific research, education, and enhancing the public's experience of the eclipse. After years of testing the initial ideas, engaging new organizations, and exploring new technologies, our team has developed a blueprint for this project. There are three main goals for this effort: 1. to learn more about the dynamic non-equilibrium processes in the corona and lower atmosphere of the Sun, 2. to educate the public about space physics, 3. provide different levels of engagement opportunities for an interested public, and 4. to understand how these various levels of engagement with a major scientific phenomena allow people to develop deeper personal connections to Science, Technology, Engineering, and Mathematics (STEM). We will meet these goals by training 1000 volunteers to take scientifically valid images and donate the images to this project, while also allowing the general public to share their images as well. During the Aug 21, 2017 eclipse, we will analyze these images in real-time to produce public-generated movies showing the corona of the Sun during totality from thousands of people. These movies will be disseminated in near real-time (on the order of 10s of minutes) to other eclipse programs, news organizations, and to the general public. Meanwhile, images collected during and after the eclipse will be available to scientists and the public for research purposes. To further engage the public, video clips, film, and a documentary will be produced prior and after the event. A science education research team will work alongside the team to understand how the project supports deeper connections to the eclipse experience.

  16. Total solar eclipse of 1995 October 24

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    1994-01-01

    A total eclipse of the sun will be visible from Asia and the Pacific Ocean on 24 Oct. 1995. The path of the moon's shadow begins in the Middle East and sweeps across India, Southeast Asia, and the waters of the Indonesian archipelago before ending at sunset in the Pacific. Detailed predictions for this event are presented and include besselian elements, geographic coordinates of the path of totality, physical ephemeris of the umbra, topocentric limb profile corrections, local circumstances for 400 cities, maps of the eclipse path, weather prospects, the lunar limb profile, and the sky during totality.

  17. Coronal structure and flattening during total solar eclipse 2006

    Directory of Open Access Journals (Sweden)

    A.A. Galal

    2012-12-01

    Full Text Available On the basis of well resolved observations of the solar corona taken at Salloum N-W of Egypt during the total solar eclipse of 2006 “the descending phase of solar cycle 23”, some aspects of the physics of the corona have been studied up to several solar radii. The magnetic structures of the white light corona were studied. The flattening coefficient e characterizes the shape of the isophotes of the whit-light corona and computed as a function of the distance from the disk center. The flattening index e during solar total eclipse 2006 was found to be 0.158. This result is in a good agreement with previous published results.

  18. Solar Radiation at Total Solar Eclipse, 29-March 2006, at Tobruq

    OpenAIRE

    A. H. Hassan; U. A. Rahoma

    2010-01-01

    Problem statement: Measurement of the different components of solar radiation and fractions of these components for the global (horizontal and tracker), direct (white and three colors, yellow, red and infrared) and diffuse solar radiation during the solar eclipse, 29 March 2006 at Tobruq, Libya (Lat. 32.08°N and Long. 23.98°E). The time interval of solar eclipse was 2 h: 40 m and the maximum magnitude of eclipse at this region was 0.995. Conclusion: The results showed th...

  19. Student artistry sparks eclipse excitement on Maui: NSO/DKIST EPO for the 2016 Partial Solar Eclipse

    Science.gov (United States)

    Schad, Thomas A.; Penn, Matthew J.; Armstrong, James

    2016-05-01

    Local creativity and artistry is a powerful resource that enhances education programs and helps us generate excitement for science within our communities. In celebration of the 2016 Solar Eclipse, the National Solar Observatory (NSO) and its Daniel K Inouye Solar Telescope (DKIST) project were pleased to engage with students across Maui County, Hawai`i, via the 2016 Maui Eclipse Art Contest. With the help of the Maui Economic Development Board and the University of Hawai'is Institute for Astronomy, we solicited art entries from all K-12 schools in Maui County approximately 6 months prior to the eclipse. Along with divisional prizes, a grand prize was selected by a panel of local judges, which was subsequently printed on 25,000 solar eclipse viewing glasses and distributed to all Maui students. We found that the impact of a locally-sourced glasses design cannot be understated. Overall, the success of this program relied upon reaching out to individual teachers, supplying educational flyers to all schools, and visiting classrooms. On the day of the eclipse, all of the art entries were prominently displayed during a community eclipse viewing event at Kalama Beach Park in Kihei, HI, that was co-hosted by NSO and the Maui Science Center. This eclipse art contest was integral to making local connections to help promote science education on Maui, and we suggest that it could be adapted to the solar community's EPO activities for the upcoming 2017 Great American Solar Eclipse.

  20. Interpretation of Historically Significant Solar and Lunar Eclipses

    Science.gov (United States)

    Muradyan, Armine; Mickaelian, A. M.

    2016-12-01

    Most of the ancient civilizations reacted with great awe and fear to the phenomena occurring in the sky and their changes. Periodically recurring movements of the Sun and the Moon attracting the attention of the astronomers, have given possibility to ancient civilizations to develop various calendars, including quite complicated ones. Since ancient times, Lunar and Solar eclipses were also among the forecasted phenomena, which have played an important role in human history. In the modern era, due to the cooperation of astronomers and historians, precise historical years and dates have been identified and the most important scientific discoveries of mankind have been proved with the help of eclipses. Most important historical Solar and Lunar eclipses, their impact on people, societies, history and science are presented and the interpretation of available to us historical events is given in this article.

  1. St. Benedict Sees the Light: Asam's Solar Eclipses as Metaphor

    Science.gov (United States)

    Olson, Roberta J. M.; Pasachoff, Jay M.

    During the Baroque period, artists worked in a style - encouraged by the Roman Catholic Church and the Council of Trent - that revealed the divine in natural forms and made religious experiences more accessible. Cosmas Damian Asam, painter and architect, and his brother Egid (Aegid) Quirin Asam, sculptor and stuccatore, were the principal exponents of eighteenth-century, southern-German religious decoration and architecture in the grand manner, the Gesamtkunstwerk. Cosmas Damian's visionary and ecstatic art utilized light, both physical and illusionistic, together with images of meteorological and astronomical phenomena, such as solar and lunar eclipses. This paper focuses on his representations of eclipses and demonstrates how Asam was galvanized by their visual, as well as metaphorical power and that he studied a number of them. He subsequently applied his observations in a series of paintings for the Benedictine order that become increasingly astronomically accurate and spiritually profound. From the evidence presented, especially in three depictions of St. Benedict's vision, the artist harnessed his observations to visualize the literary description of the miraculous event in the Dialogues of St. Gregory the Great, traditionally a difficult scene to illustrate, even for Albrecht Dürer. Asam painted the trio at Einsiedeln, Switzerland (1724-27); Kladruby, the Czech Republic (1725-27), where he captured the solar corona and the "diamond-ring effect"; and Weltenburg, Germany (1735), where he also depicted the diamond-ring effect at a total solar eclipse. We conclude that his visualizations were informed by his personal observations of the solar eclipses on 12 May 1706, 22 May 1724, and 13 May 1733. Asam may have also known the eclipse maps of Edmond Halley and William Whiston that were issued in advance. Astronomers did not start studying eclipses scientifically until the nineteenth century, making Asam's depictions all the more fascinating. So powerful was the

  2. Five Millennium Catalog of Solar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE)

    Science.gov (United States)

    Espenak, Fred; Meeus, Jean

    2008-01-01

    This catalog is a supplement to the "Five Millennium Canon of Solar Eclipses." It includes additional information for each eclipse that could not be included in the original 648-page publication because of size limits. The data tabulated for each eclipse include the catalog number, canon plate number, calendar date, Terrestrial Dynamical Time of greatest eclipse, (Delta)T, lunation number, Saros number, eclipse type, Quincena Lunar Eclipse parameter, gamma, eclipse magnitude, geographic coordinates of greatest eclipse (latitude and longitude), and the circumstances at greatest eclipse (i.e., Sun altitude and azimuth, path width, and central line duration). The Canon and the Catalog both use the same solar and lunar ephemerides as well as the same values of (Delta)T. This 1-to-1 correspondence between them will enhance the value of each. The researcher may now search, evaluate, and compare eclipses graphically (Canon) or textually (Catalog).

  3. Five Millennium Catalog of Solar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE)-Revised

    Science.gov (United States)

    Espenak, Fred; Meeus, Jean

    2009-01-01

    This catalog is a supplement to the "Five Millennium Canon of Lunar Eclipses. "It includes additional information for each eclipse that could not be included in the original publication because of size limits. The data tabulated for each eclipse include the catalog number, canon plate number, calendar date, Terrestrial Dynamical Time of greatest eclipse, (Delta)T, lunation number, Saros number, eclipse type, Quincena Solar Eclipse parameter, gamma, penumbral and umbral eclipse magnitudes, durations of penumbral, partial and total eclipse phases, and geographic coordinates of greatest eclipse(latitude and longitude). The Canon and the Catalog both use the same solar and lunar ephemerides as well as the same values of (Delta)T. This 1-to-1 correspondence between them will enhance the value of each. The researcher may now search, evaluate, and compare eclipses graphically (Canon) or textually (Catalog).

  4. The Trojan war dated by two solar eclipses.

    Science.gov (United States)

    Henriksson, Goran

    The Trojan War was very significant for the ancient Greeks and they dated historical events according to the number of years after the fall of Troy. However, there was already in antiquity no consensus as to the exact date of the war when compared with different epochs. Even after the modern discovery of the ancient city, there has been disagreement among different excavators as to which layer corresponds to the city mentioned in the Iliad attributed to Homer. In this paper an attempt is made to identify the strange obscuration of the sun that occurred during the final battle of the Iliad as a total solar eclipse close to the southern border of the zone of totality. There exists only one solar eclipse that corresponds to the description in the text and this is the total solar eclipse of June 11, in 1312 BC. When I first presented this date in 1986, there was a difference of about 60 years compared with the most common archaeological dating at that time. My date is now fully supported by the latest results from the German-American excavation that identifies the fall of Homer's Troy with the destruction of the archaeological layer Troy VIh, dated to about 1300 BC. Further independent support is provided by another solar eclipse that dates the reign of the Hittite king Muwatalli II. This king wrote a letter to king Alaksandu in Wilusa, identified as the Hittite name for Ilios, the most frequently used name for Troy in the Iliad. Alexander was another name for Paris who abducted Helen, the crime that resulted in the war. Muwatalli II was king 1315-1297 BC, according to the chronology for the Hittite Kingdom based on a solar eclipse in 1335 BC, during the tenth year of King Mursili II (1345- 1315 BC), the father of Muwatalli II.

  5. Annular and Total Solar Eclipses of 2003

    Science.gov (United States)

    Espenak, Fred; Anderson, Jay

    2002-01-01

    On Saturday, 2003 May 31, an annular eclipse of the Sun will be visible from a broad corridor that traverses the North Atlantic. The path of the Moon's antumbral shadow begins in northern Scotland, crosses Iceland and central Greenland, and ends at sunrise in Baffin Bay (Canada). A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes most of Europe, the Middle East, central and northern Asia, and northwestern North America. The trajectory of the Moon's shadow is quite unusual during this event. The shadow axis passes to the far north where it barely grazes Earth's surface. In fact, the northern edge of the antumbra actually misses Earth so that one path limit is defined by the day/night terminator rather than by the shadow's upper edge. As a result, the track of annularity has a peculiar "D" shape that is nearly 1200 kilometers wide. Since the eclipse occurs just three weeks prior to the northern summer solstice, Earth's northern axis is pointed sunwards by 22.8 deg. As seen from the Sun, the antumbral shadow actually passes between the North Pole and the terminator. As a consequence of this extraordinary geometry, the path of annularity runs from east to west rather than the more typical west to east. The event transpires near the Moon's ascending node in Taurus five degrees north of Aldebaran. Since apogee occurs three days earlier (May 28 at 13 UT), the Moon's apparent diameter (29.6 arc-minutes) is still too small to completely cover the Sun (31.6 arc-minutes) resulting in an annular eclipse.

  6. Polar plumes dynamics observed during total solar eclipses

    Science.gov (United States)

    Barczynski, K.; Bělík, M.; Marková, E.

    2010-12-01

    Following the successful observation of significant activity in the polar plume during the total solar eclipse in 2006, the analysis of the Sun's polar regions was also carried out in the images obtained in multi-station observations of the eclipse of 2008. In this work polar plumes showing similar although much less significant manifestation of the dynamics have been identified. The dynamics evolution rates have been obtained from comparing the pictures taken at different times. The results are compared with the corresponding phenomena observed in X-rays from the HINODE satellite.

  7. The Astrophysics of the Solar Corona at the August 21, 2017, American Total Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay

    2017-01-01

    The first total solar eclipse to cross the United States from coast to coast in 99 years will occur on August 21, 2017, with a 70-mile-wide path of totality from Oregon to South Carolina, with cloudiness statistics more favorable in the northwest than in the southeast. I will discuss a series of observations of the solar corona made during recent solar eclipses and related spacecraft observations. I will further discuss plans for using the 2017 eclipse for furthering our studies of the heating of the solar corona to millions of kelvins, of the dynamics of coronal mass ejections and polar plumes, and of the response of the corona to the solar magnetic field. I will conclude by discussing public-education plans for the eclipse, during which the whole U.S., Mexico, Central America, and Canada will enjoy a partial eclipse. My work at solar eclipses has recently been supported by the NSF and the Committee for Research and Exploration of the National Geographic Society, and I thank them both for research grants for our scientific studies of the 2017 total eclipse, including AGS-1602461 from the NSF and 987816 from National Geographic.

  8. Solar Radiation at Total Solar Eclipse, 29-March 2006, at Tobruq

    Directory of Open Access Journals (Sweden)

    A. H. Hassan

    2010-01-01

    Full Text Available Problem statement: Measurement of the different components of solar radiation and fractions of these components for the global (horizontal and tracker, direct (white and three colors, yellow, red and infrared and diffuse solar radiation during the solar eclipse, 29 March 2006 at Tobruq, Libya (Lat. 32.08°N and Long. 23.98°E. The time interval of solar eclipse was 2 h: 40 m and the maximum magnitude of eclipse at this region was 0.995. Conclusion: The results showed that the maximum percent of color in the total direct solar radiation during the true eclipse from the first contact to the end contact was in the infrared, where the percent were in the green (11.74%, yellow (15.69%, red (14.88% and infrared (57.68%.

  9. The Solar Eclipse Mural Series by Howard Russell Butler

    Science.gov (United States)

    Pasachoff, J. M.; Olson, R. J. M.

    2016-01-01

    There is a rich trove of astronomical phenomena in works of art by artists from the greater New York area, a trend that is even more pronounced in the oeuvres of New York City residents through the present day. A case in point is the trio of oil paintings by artist (and former physics professor) Howard Russell Butler depicting total solar eclipses in 1918, 1923, and 1925 that are based on his own observations. They were long displayed in the former art-deco building of the Hayden Planetarium of the American Museum of Natural History, the location of this conference. (The Museum also has nine other Butler paintings, none of which are currently exhibited.) Since the eclipse paintings have been in storage for many years, these once famous works are now virtually forgotten. Based on our research as an astronomer who has seen sixty-two solar eclipses and an art historian who has written extensively about astronomical imagery, we will discuss Butler's Solar Eclipse Triptych to explore its place in the history of astronomical imaging.

  10. Tomographic Study of Ionospheric Effects Associated with a Solar Eclipse

    Institute of Scientific and Technical Information of China (English)

    WuXiong-bin; XuJi-sheng; MaShu-ying; TianMao

    2003-01-01

    This paper studies the ionospheric effects associated with the solar eclipse of October 24th, 1995 by means of Computerized Ionospheric Tomography (CIT). Since the reconstructed profiles from experimental CIT are sporadically located in time, a time domain interpolation method based on Singular Value Decomposition (SVD) technique is proposed and applied to extract the ionospheric effects. The effects can be extracted by comparison analysis between the interpolated CIT profiles of the eclipse days and that of the reference day that are time-aligned. A series of figs have been obtained showing the attenuation of photonization effect at low altitudes and the weakening of plasma's transportation process at high altitudes, etc. The photonization effect recovered to normal level soon after the last contact. The maximum electron density diminishing is observed about 2 h after the eclipse maximum and the effects seem vanished in the hours followed. Analysis on vertical TEC's latitudinal-temporal variation gives similar conclusions.

  11. Measuring the IR solar corona during the 2017 eclipse

    Science.gov (United States)

    Bryans, Paul; Hannigan, James; Philip, Judge; Larson, Brandon; Sewell, Scott; McIntire, Lauren

    2016-05-01

    On 21 August 2017 a total solar eclipse will pass across the continental United States, offering a unique opportunity to conduct scientific research of the solar atmosphere. With the light from the Sun eclipsed, the solar corona becomes visible in a way not possible when swamped by the light from the photosphere. The infrared (IR) spectrum of the corona, in particular, is predicted to contain some of the most magnetically sensitive spectral lines. However, no comprehensive survey of this spectral range has been carried out to date. Here, we describe a Fourier Transform Spectrometer, currently under construction at NCAR, to measure the IR spectrum from 2 to 12 microns. We will discuss the operation of the experiment, which will be deployed along the path of totality in Wyoming, and the scientific results we hope to obtain.

  12. Sky color near the horizon during a total solar eclipse.

    Science.gov (United States)

    Gedzelman, S D

    1975-12-01

    A theory for the color of the sky near the horizon for an observer in the umbral region of a total solar eclipse is presented. The model uses a Rayleigh scattering atmosphere, and the light reaching the observer is a beam of singly scattered sunlight, which, in turn, has suffered depletion by scattering in its passage from outside the shadow region. The model predicts both the red color observed in the lowest 8 degrees of the sky for the total solar eclipse of 30 June 1973 and the enriched blue color of the sky at any elevation angle greater than the solar elevation angle. The model is also adapted to explain the reddening of the horizon sky observed during such times as when a dark cloud passes overhead or when the light from a large city is seen from the distance at night.

  13. The Citizen CATE Experiment for the 2017 Total Solar Eclipse

    Science.gov (United States)

    Penn, M. J.

    2015-12-01

    The path of the total solar eclipse of 21 August 2017 passes over about 10 million homes in the USA. Tens of millions more people will travel to the path of totality to view the eclipse first-hand. Using TV and the internet broadcasts, hundreds of millions of people will watch the eclipse, making the event the most viewed astronomical event in the history of mankind. The Citizen Continental-America Telescopic Eclipse (CATE) Experiment for 2017 is being developed at the National Solar Observatory in partnership with universities, schools, astronomy clubs, and corporations. The CATE experiment will use more than 60 identical telescopes equipped with digital cameras positioned from Oregon to South Carolina to image the solar corona. The project will then splice these images together to show the corona during a 90-minute period, revealing for the first time the plasma dynamics of the inner solar corona. The goals for the highly leveraged CATE experiment are diverse and range from providing an authentic STEM research experience for students and lifelong learners, to making state-of-the-art solar coronal observations of the plasma dynamics of coronal polar plumes, to increasing the US scientific literacy. A key goal of this experiment is to donate the telescope and camera system to the volunteer who collects data with it during the total eclipse. The instrument will be then used for a variety of follow-up citizen science projects in astronomy, ranging from solar to cometary to variable star observations. For this reason no government funding is being sought for the equipment costs, but rather private and corporate sources are being developed. The data collected for the 2017 eclipse will be freely available to the scientific, education and amateur astronomy communities. Crowd sourcing the data collection is an essential part of this project, as there are not enough solar physicists in this country to collect these observations. Finally, each site is expected to collect

  14. Your guide to the 2017 total solar eclipse

    CERN Document Server

    Bakich, Michael E

    2016-01-01

    In this book Astronomy Magazine editor Michael Bakich presents all the information you’ll need to be ready for the total solar eclipse that will cross the United States on August 21, 2017. In this one resource you’ll find out where the eclipse will occur, how to observe it safely, what you’ll experience during the eclipse, the best equipment to choose, how to photograph the event, detailed weather forecasts for locations where the Moon’s shadow will fall, and much more. Written in easy-to-understand language (and with a glossary for those few terms you may not be familiar with), this is the must-have reference for this unique occurrence. It’s not a stretch to say that this eclipse will prove to be the most viewed sky event in history. That’s why even now, more than a year before the eclipse, astronomy clubs, government agencies, cities — even whole states — are preparing for the unprecedented onslaught of visitors whose only desire is to experience darkness at midday. Bakich informs observers ...

  15. Five Millennium Canon of Solar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE)

    Science.gov (United States)

    Espenak, Fred; Meeus, Jean

    2006-01-01

    During 5,000-year period from -1999 to +3000 (2000BCE to 3000CE), Earth will experience 11,898 eclipses of the Sun. The statistical distribution of eclipse types for this interval is as follows: 4,200 partial eclipses, 3956 annular eclipses, 3173 total eclipses,and 569 hybrid eclipses. Detailed global maps for each of the 11,898 eclipses delineate the geographic regions of visibility for both the penumbral (partial) and umbral or antumbral (total, annular, or hybrid) phases of every event. Modern political borders are plotted to assist in the determination of eclipse visibility. The uncertainty in Earth's rotational period expressed in the parameter (delta)T and its impact on the geographic visibility of eclipses in the past and future is discussed.

  16. Solar coronal and magnetic field observations near the time of the 1988 March 18 solar eclipse

    Science.gov (United States)

    Sime, D. G.; Fisher, R. R.; Mickey, D. L.

    1988-01-01

    Observations made during the interval March 1-31, 1988, are presented which were designed to provide a synoptic context in which data from the March 18, 1988, total solar eclipse can be interpreted. Daily observations made with the Mark III K-coronameter and the H-alpha prominence monitor at the Mauna Loa Solar Observatory, along with photographic records of the Sun in H-alpha from the flare patrol at Mees Solar Observatory on Haleakala, Maui, are included. Observations of the longitudinal component of the photospheric magnetic field made at Mees Solar Observatory were also gathered around the period of the eclipse. Together with the white-light image of the corona at the eclipse, these coronal and magnetic field observations assembled into synoptic maps for this epoch, are presented. On the basis of these observations, an interpretation of the global density distribution of the corona at the time of the eclipse is constructed.

  17. Eclipse effects on field crops and marine zooplankton: the 29 March 2006 total solar eclipse

    Directory of Open Access Journals (Sweden)

    G. Economou

    2008-08-01

    Full Text Available Some effects in the biosphere from the Total Solar Eclipse of 29 March 2006 were investigated in field crops and marine zooplankton. Taking into account the decisive role of light on plant life and productivity, measurements of photosynthesis and stomatal behaviour were conducted on seven important field-grown cereal and leguminous crops. A drop in photosynthetic rates, by more than a factor of 5 in some cases, was observed, and the minimum values of photosynthetic rates ranged between 3.13 and 10.13 μmol CO2 m−2 s−1. The drop in solar irradiance and the increase in mesophyll CO2-concentration during the eclipse did not induce stomatal closure thus not blocking CO2 uptake by plants. Light effects on the photochemical phase of photosynthesis may be responsible for the observed depression in photosynthetic rates. Field studies addressing the migratory responses of marine zooplankton (micro-zooplankton (ciliates, and meso-zooplankton due to the rapid changes in underwater light intensity were also performed. The light intensity attenuation was simulated with the use of accurate underwater radiative transfer modeling techniques. Ciliates, responded to the rapid decrease in light intensity during the eclipse adopting night-time behaviour. From the meso-zooplankton assemblage, various vertical migratory behaviours were adopted by different species.

  18. Eclipse effects on field crops and marine zooplankton: the 29 March 2006 total solar eclipse

    Science.gov (United States)

    Economou, G.; Christou, E. D.; Giannakourou, A.; Gerasopoulos, E.; Georgopoulos, D.; Kotoulas, V.; Lyra, D.; Tsakalis, N.; Tzortziou, M.; Vahamidis, P.; Papathanassiou, E.; Karamanos, A.

    2008-08-01

    Some effects in the biosphere from the Total Solar Eclipse of 29 March 2006 were investigated in field crops and marine zooplankton. Taking into account the decisive role of light on plant life and productivity, measurements of photosynthesis and stomatal behaviour were conducted on seven important field-grown cereal and leguminous crops. A drop in photosynthetic rates, by more than a factor of 5 in some cases, was observed, and the minimum values of photosynthetic rates ranged between 3.13 and 10.13 μmol CO2 m-2 s-1. The drop in solar irradiance and the increase in mesophyll CO2-concentration during the eclipse did not induce stomatal closure thus not blocking CO2 uptake by plants. Light effects on the photochemical phase of photosynthesis may be responsible for the observed depression in photosynthetic rates. Field studies addressing the migratory responses of marine zooplankton (micro-zooplankton (ciliates), and meso-zooplankton) due to the rapid changes in underwater light intensity were also performed. The light intensity attenuation was simulated with the use of accurate underwater radiative transfer modeling techniques. Ciliates, responded to the rapid decrease in light intensity during the eclipse adopting night-time behaviour. From the meso-zooplankton assemblage, various vertical migratory behaviours were adopted by different species.

  19. There's An App For That: Planning Ahead for the Solar Eclipse in August 2017

    Science.gov (United States)

    Chizek Frouard, Malynda R.; Lesniak, Michael V.; Bell, Steve

    2017-01-01

    With the total solar eclipse of 2017 August 21 over the continental United States approaching, the U.S. Naval Observatory (USNO) on-line Solar Eclipse Computer can now be accessed via an Android application, available on Google Play.Over the course of the eclipse, as viewed from a specific site, several events may be visible: the beginning and ending of the eclipse (first and fourth contacts), the beginning and ending of totality (second and third contacts), the moment of maximum eclipse, sunrise, or sunset. For each of these events, the USNO Solar Eclipse 2017 Android application reports the time, Sun's altitude and azimuth, and the event's position and vertex angles. The app also lists the duration of the total phase, the duration of the eclipse, the magnitude of the eclipse, and the percent of the Sun obscured for a particular eclipse site.All of the data available in the app comes from the flexible USNO Solar Eclipse Computer Application Programming Interface (API), which produces JavaScript Object Notation (JSON) that can be incorporated into third-party Web sites or custom applications. Additional information is available in the on-line documentation (http://aa.usno.navy.mil/data/docs/api.php).For those who prefer using a traditional data input form, the local circumstances can still be requested at http://aa.usno.navy.mil/data/docs/SolarEclipses.php.In addition the 2017 August 21 Solar Eclipse Resource page (http://aa.usno.navy.mil/data/docs/Eclipse2017.php) consolidates all of the USNO resources for this event, including a Google Map view of the eclipse track designed by Her Majesty's Nautical Almanac Office (HMNAO).Looking further ahead, a 2024 April 8 Solar Eclipse Resource page (http://aa.usno.navy.mil/data/docs/Eclipse2024.php) is also available.

  20. Photo-induced foveal injury after viewing a solar eclipse.

    Science.gov (United States)

    Källmark, Fredrik P; Ygge, Jan

    2005-10-01

    To study the injury to and possible recovery of the visual function and foveal morphology in patients with photo-induced foveal injury due to watching the solar eclipse of August 11th, 1999 in Stockholm, Sweden. Fifteen patients, all of whom viewed the solar eclipse, were followed for 1 year, during which their visual symptoms were recorded and visual acuity (VA) was tested, and ophthalmoscopy and scanning laser ophthalmoscopy were performed. Photo-induced foveal injury gave rise to subjective visual disturbances, reduced VA and morphological changes in the fovea. Central scotomas could still be seen in all patients 1 year after the foveal injury. Photo-induced foveal injury gave rise to subjective visual disturbances, reduced VA and morphological changes in the fovea. Scanning laser ophthalmoscopy offers the possibility of detailed examination of small retinal lesions, which can sometimes be difficult to localize with ophthalmoscopy.

  1. Solar eclipse sign of intussusception on barium enema.

    Science.gov (United States)

    Raveenthiran, V

    2002-01-01

    The colographic appearance of intussusception is variously described as a claw sign, pincer defect, shouldering effect, and coiled-spring pattern. This report adds a new radiographic sign to the list. An end-on view of an intussusception on barium enema shows a ring of contrast resembling a solar eclipse. Familiarity with this bizarre appearance is desirable, lest it may be mistaken for spillage of barium due to a colonic perforation.

  2. Calcification of thoracic aorta – solar eclipse sign

    Science.gov (United States)

    Dhoble, Abhijeet; Puttarajappa, Chethan

    2008-01-01

    Background Calcification of thoracic aorta is very common in old people, especially ones with hypertension. This can sometime be visible on plain chest radiograph. Case Presentation We present a case of a male patient who had extensive deposition of calcium in the thoracic aorta. Conclusion The relationship between aortic calcification and coronary atherosclerosis remains contentious. Computed tomography of the thorax can display this calcification which appears like 'solar eclipse'. PMID:18759981

  3. [Eclipse retinopathy : A case series after the partial solar eclipse on 20 March 2015].

    Science.gov (United States)

    Bachmeier, I; Helbig, H; Greslechner, R

    2017-01-01

    Solar retinopathy refers to damage to the central macula caused by exposure to intense solar radiation, most frequently observed after a solar eclipse. Description of the morphological changes in spectral domain optical coherence tomography (SD-OCT) and the clinical course in patients with acute solar retinopathy. The study included a retrospective analysis of 12 eyes from 7 patients with solar retinopathy after the partial solar eclipse on 20 March 2015. Best corrected visual acuity, fundus changes and SD-OCT findings were analyzed. Out of the 7 patients 5 underwent treatment with 1 mg prednisolone per kg body weight. The average age of the patients was 30.1±13.1 years. Best corrected visual acuity was 0.65 at initial presentation. In the acute stage all affected eyes showed a small yellowish lesion in the centre of the fovea in the fundoscopic examination. In SD-OCT the continuity of all layers in the foveola appeared disrupted. In the follow-up examination these changes were partially resolved. After 2 months SD-OCT revealed a small defect of the ellipsoid zone. In one patient the defect could not be shown due to slightly excentric imaging sections. Best corrected visual acuity increased to 0.97. The SD-OCT is an appropriate tool to determine the exact localization of the site of damage and for follow-up examination in solar retinopathy. In the acute phase it shows a disruption of the continuity of all layers in the foveola. Despite good recovery of visual acuity a small central defect of the ellipsoid zone remains in the long term.

  4. [Survey of ocular injury by solar eclipse 2009].

    Science.gov (United States)

    Obana, Akira; Takahashi, Jun; Ohnishi, Kouji; Shinohara, Hideo; Matsuo, Atsushi; Saito, Izumi; Ohkawa, Takuya; Ono, Tomoko

    2011-07-01

    Incidence of ocular injury caused by the solar eclipse of 2009 has been investigated using the questionnaire of the Japan Committee of the International Year of Astronomy 2009. The questionnaire was available to the public on the website. Answers were obtained from 14 people (12 men, 2 women), aged from sixteen to fifty-four. All had looked at the sun either with the naked eye or through some shading device (plastic sheet, plastic bag, compact disc, etc.) the safty of which is unknown. Reported symptoms included a sense of incongruity, heat, pain, central scotoma or visual disturbance, classified into four periods of duration. Three people with transient symptoms watched the eclipse with the naked eye for one minute in cloudy weather. Three people with symptoms lasting for one day and three people with symptoms lasting for one week had watched it with the naked eye and some shading device for 10 minutes in cloudy weather. Five people with symptoms lasting for more than one week watched the eclipse with the naked eye and through some sort of device in fine or slightly cloudy weather. Three people consulted their ophthalmologist. Those who reported adverse symptoms did not comply with the instructions for safe watching of the eclipse and the duration of the symptoms depended on the weather and the type of device used.

  5. White light coronal structures and flattening during six total solar eclipses

    OpenAIRE

    B.A. Marzouk; P. Stoeva; Stoev, A.

    2016-01-01

    Solar corona is very important part of the solar atmosphere, which is not available every time and it is very difficult to observe it. From solar corona we can get more information about outer sun layers. Large-scale structure of the solar corona can be studied during total solar eclipses. The structure, shape and brightness of the solar corona significantly change from eclipse to eclipse. They depend on activity of the sun. At maximum solar activity, the corona is very bright and uniform ...

  6. The Solar Eclipse Predictions of Chiljeongsam-Oepyeon in Early Choseon

    Science.gov (United States)

    Ahn, Young Sook; Lee, Yong Sam

    2004-12-01

    The history books of East Asia about astronomical phenomena have the more records of the solar eclipse frequently than any other ones. It is because traditionally, the solar eclipse meaned the fate of dynasty and the king's rule. The Sun, the biggest thing in the heaven symbolized the king, and the solar eclipse foresaw that the king had the problem in private including the body, and the country might suffer from difficulties in a great scale. So the king and all of the ministers used to gather to hold a ceremony named Gusikrye which solar eclipse may pass safely. Consequently, kings always had concernments on collecting informations of solar eclipse. Inspite of importance of solar eclipse predictions, but at the beginning of the Choseon, the predictions of the solar eclipse didn't fit. King Sejong compiled the Chiljeongsan-naepion and the Chiljeongsan-oepyeon to calculate the celestial phenomena including the solar eclipse. By the publications of these two books, the calendar making system of Choseon was firmly established. The Chiljeongsan-oepyeon adopted Huihui calendar of Arabia. The Solar eclipse predictions of Chiljeongsan-oepyeon were relative correct compared to modern method in early Choseon dynasty.

  7. Simulation of solar radiation during a total solar eclipse: a challenge for radiative transfer

    Directory of Open Access Journals (Sweden)

    C. Emde

    2007-01-01

    Full Text Available A solar eclipse is a rare but spectacular natural phenomenon and furthermore it is a challenge for radiative transfer modeling. Whereas a simple one-dimensional radiative transfer model with reduced solar irradiance at the top of the atmosphere can be used to calculate the brightness during partial eclipses a much more sophisticated model is required to calculate the brightness (i.e. the diffuse radiation during the total eclipse. The reason is that radiation reaching a detector in the shadow gets there exclusively by horizontal (three-dimensional transport of photons in a spherical shell atmosphere. In this study the first accurate simulations are presented examplified by the solar eclipse at 29 March 2006. Using a backward Monte Carlo model we calculated the diffuse radiation in the umbra and simulated the changing colors of the sky. Radiance and irradiance are decreased by 3 to 4 orders of magnitude, depending on wavelength. We found that aerosol has a comparatively small impact on the radiation in the umbra. We also estimated the contribution of the solar corona to the radiation under the umbra and found that it is negligible compared to the diffuse solar radiation in most parts of the spectrum. Spectrally resolved measurements in the umbra are not yet available. They are challenging due to the low intensity and therefore need careful planning. The new model may be used to support measurements during future solar eclipses.

  8. Safety criteria for flying E-sail through solar eclipse

    CERN Document Server

    Janhunen, Pekka

    2015-01-01

    The electric solar wind sail (E-sail) propellantless propulsion device uses long, charged metallic tethers to tap momentum from the solar wind to produce spacecraft propulsion. If flying through planetary or moon eclipse, the long E-sail tethers can undergo significant thermal contraction and expansion. Rapid shortening of the tether increases its tension due to inertia of the tether and a Remote Unit that is located on the tether tip (a Remote Unit is part of typical E-sail designs). We analyse by numerical simulation the conditions under which eclipse induced stresses are safe for E-sail tethers. We calculate the closest safe approach distances for Earth, Moon, Venus, Mars, Jupiter, Ceres and an exemplary 300 km main belt asteroid Interamnia for circular, parabolic and hyperbolic orbits. We find that any kind of eclipsing is safe beyond approximately 2.5 au distance, but for terrestrial planets safety depends on the parameters of the orbit. For example, for Mars the safe distance with 20 km E-sail tether li...

  9. The solar corona through the sunspot cycle: preparing for the August 21, 2017, total solar eclipse

    Science.gov (United States)

    Pasachoff, Jay M.; Seaton, Daniel; Rusin, Vojtech

    2017-01-01

    We discuss the evolution of the solar corona as seen at eclipses through the solar-activity cycle. In particular, we discuss the variations of the overall shape of the corona through the relative proportions of coronal streamers at equatorial and other latitudes vs. polar plumes. We analyze the two coronal mass ejections that we observed from Gabon at the 2013 total solar eclipse and how they apparently arose from polar crown filaments, one at each pole. We describe the change in the Ludendorff flattening index from solar maximum in one hemisphere as of the 2013 eclipse through the 2015 totality's corona we observed from Svalbard and, with diminishing sunspot and other magnetic activity in each hemisphere, through the 2016 corona we observed from Ternate, Indonesia.We discuss our observational plans for the August 21, 2017, total solar eclipse from our main site in Salem, Oregon, and subsidiary sites in Madras, OR; Carbondale, IL; and elsewhere, our main site chosen largely by its favorable rating in cloudiness statistics. We discuss the overlapping role of simultaneous spacecraft observations, including those expected not only from NASA's SDO, ESA's SWAP on PROBA2, and NRL/NASA/ESA's LASCO on SOHO but also from the new SUVI (Solar Ultraviolet Imager) aboard NOAA's GOES-R satellite, scheduled as of this writing to have been launched by the time of this January 2017 meeting.Our research on the 2013 and 2015 total solar eclipses was supported by grants from the Committee for Research and Exploration of the National Geographic Society (NG-CRE). Our research on the 2017 total solar eclipse is supported by both NG-CRE and the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation.

  10. The 2017 solar eclipse and Majorana & Allais gravity anomalies

    Science.gov (United States)

    Munera, Hector A.

    2017-01-01

    Two little known anomalies hint to phenomena beyond current theory. Majorana effect: around 1920 in a series of well-designed experiments with a chemical laboratory balance, Quirino Majorana found in Italy that mercury (Hg) and lead (Pb) might shield terrestrial gravity. Majorana experiments were never repeated by the international scientific community. Instead his results were dismissed on theoretical claims: a) unobserved heating of earth by absorption of gravity, and b) unobserved cyclic lunar perturbation of solar gravity at earth’s surface. However, Majorana critics missed the crucial fact that shielding is not mere absorption, but also scattering, and that atomic number Z of matter in the moon is much lower than Z=80 (Hg) and Z=82 (Pb). From the June 30/1954 solar eclipse onwards, high-quality mechanical gravimeters were used to search for Majorana shielding by the moon. Results are positive, provided that shielding is interpreted as scattering rather than absorption of gravity by moon (H. A. Munera, Physics Essays 24, 428-434, 2011). Allais effect: during the same 1954 eclipse (partial in Paris) Maurice Allais had in operation a sensitive paraconical pendulum for a very different purpose. Surprisingly, the pendulum was perturbed by the eclipse, condition repeated once again in a 1959 solar eclipse, also partial in Paris. During the past sixty years, paraconical, torsion and Foucault pendula, and other mechanical devices, have been used to (dis)confirm Allais effect, but the results are not conclusive thus far. A book edited by this author (Should the laws of gravitation be revised? Apeiron 2011) describes some of those observations. Various unexpected effects, some of them torsional, appear both near the optical shadow, and far away. The Sun-Moon-Earth alignment in a solar eclipse allows detection on the terrestrial surface of the dark matter flow scattered on moon’s surface (flow not hitting earth in other geometries). Rotation of moon may induce

  11. Visibility of stars, halos, and rainbows during solar eclipses.

    Science.gov (United States)

    Können, Gunther P; Hinz, Claudia

    2008-12-01

    The visibility of stars, planets, diffraction coronas, halos, and rainbows during the partial and total phases of a solar eclipse is studied. The limiting magnitude during various stages of the partial phase is presented. The sky radiance during totality with respect to noneclipse conditions is revisited and found to be typically 1/4000. The corresponding limiting magnitude is +3.5. At totality, the signal-to-background ratio of diffraction coronas, halos, and rainbows has dropped by a factor of 250. It is found that diffraction coronas around the totally eclipsed Sun may nevertheless occur. Analyses of lunar halo observations during twilight indicate that bright halo displays may also persist during totality. Rainbows during totality seem impossible.

  12. Public outreach and education during the 2016 total solar eclipse in Palu and Malang

    Science.gov (United States)

    Rachmadian, A. P.; Kunjaya, C.; Wahono, W.; Anugrah, A. A.

    2016-11-01

    MAGIC (Ma Chung Galactic Club) of Ma Chung University, Malang, is one of the amateur astronomers club who did public outreach and education during the Total Solar Eclipse March 9, 2016. The motivation for doing this was the bad experience during Total Solar Eclipse 1983. At that time the Indonesian government forbid the people to observe the Total Solar Eclipse in a way to avoid blindness. We try to fix this misunderstanding by educating people the safe way to enjoy the partial and total solar eclipse. MAGIC team was divided into two teams, one team went to Palu and did the solar eclipse related education in six high schools before and during the eclipse. The other team did the observation on Ma Chung University campus, Malang, to accompany people who want to see the partial solar eclipse through filtered telescopes. The sky during the solar eclipse was clear both in Malang and Palu. People were very excited and satisfied with the solar eclipse, and their interest to astronomy is increased.

  13. Eclipse effects on field crops and marine zooplankton: the 29 March 2006 Total Solar Eclipse

    Directory of Open Access Journals (Sweden)

    G. Economou

    2008-01-01

    Full Text Available The effects in the biosphere from the Total Solar Eclipse of 29 March 2006 were investigated in field crops and marine zooplankton. Taking into account the decisive role of light on the photoenergetic and photoregulatory plant processes, measurements of photosynthesis and stomatal behaviour were conducted on seven important field-grown cereal and leguminous crops. A drop in photosynthetic rates, by more than a factor of 5 in some cases, was observed, and the minimum values of photosynthetic rates ranged between 3.13 and 10.13 μmol CO2 m−2 s−1. However, since solar irradiance attenuation has not at the same time induced stomatal closure thus not blocking CO2 uptake by plants, it is probably other endogenous factors that has been responsible for the observed fall in photosynthetic rates. Field studies addressing the migratory responses of marine zooplankton (micro-zooplankton (ciliates, and meso-zooplankton due to the rapid changes in underwater light intensity were also performed. The light intensity attenuation was simulated with the use of accurate underwater radiative transfer modeling techniques. Ciliates, responded to the rapid decrease in light intensity during the eclipse adopting night-time behaviour. From the meso-zooplankton assemblage, various vertical migratory behaviours were adopted by different species.

  14. Eclipse retinopathy: follow up of 36 cases after April 1995 solar eclipse in Pakistan.

    Science.gov (United States)

    Awan, Abdul Aziz; Khan, Tajamul; Mohammad, Sardar; Arif, Abdus Salam

    2002-01-01

    A study was carried out at the Department of Ophthalmology Ayub Medical College, Abbottabad from April 1995 to April 2002 to study the visual acuity changes in patients of solar eclipse retinopathy. Thirty-six patients with solar eclipse retinopathy were seen. Examination included assessment of Visual Acuity (VA), Slit Lamp examination, Fundoscopy, Fundus Photography and Fundus Fluorescein Angiography where the VA was 6/60. The patients were seen at weekly intervals then at monthly interval and later annually. Poor visual acuity was seen in all patients, after images in 28 patients, Erythopsia in 25 patients and Central Scotoma in 23 patients. Eye involvement was unilateral in 27 cases and bilateral in 9 cases. Twenty-nine patients were male and 7 patients were female. The commonest age group was between 10-30 years. Complete recovery was seen in 26 patients, 7 made partial recovery while in three patients the visual acuity remained poor. Maximum recovery occurred between two weeks to six months. After six months, no changes in the visual acuity or macular lesion were noticed.

  15. [Eclipse retinopathy].

    Science.gov (United States)

    Johannessen, Simon; Høgsbro, Malou

    2014-11-10

    Eclipse retinopathy is a condition with macular damage resulting from viewing of a solar eclipse. This case report illustrates how eclipse retinopathy was diagnosed with a delay of more than 30 years. The report also summarises how solar eclipse can be observed without risk of retinal damage.

  16. Satellite observations of surface temperature during the March 2015 total solar eclipse.

    Science.gov (United States)

    Good, Elizabeth

    2016-09-28

    The behaviour of remotely sensed land surface temperatures (LSTs) from the spinning-enhanced visible and infrared imager (SEVIRI) during the total solar eclipse of 20 March 2015 is analysed over Europe. LST is found to drop by up to several degrees Celcius during the eclipse, with the minimum LST occurring just after the eclipse mid-point (median=+1.5 min). The drop in LST is typically larger than the drop in near-surface air temperatures reported elsewhere, and correlates with solar obscuration (r=-0.47; larger obscuration = larger LST drop), eclipse duration (r=-0.62; longer duration = larger LST drop) and time (r=+0.37; earlier eclipse = larger LST drop). Locally, the LST drop is also correlated with vegetation (up to r=+0.6), with smaller LST drops occurring over more vegetated surfaces. The LSTs at locations near the coast and at higher elevation are also less affected by the eclipse. This study covers the largest area and uses the most observations of eclipse-induced surface temperature drops to date, and is the first full characterization of satellite LST during an eclipse (known to the author). The methods described could be applied to Geostationary Operational Environmental Satellite (GOES) LST data over North America during the August 2017 total solar eclipse.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  17. Solar Eclipse Video Captured by STEREO-B

    Science.gov (United States)

    2007-01-01

    No human has ever witnessed a solar eclipse quite like the one captured on this video. The NASA STEREO-B spacecraft, managed by the Goddard Space Center, was about a million miles from Earth , February 25, 2007, when it photographed the Moon passing in front of the sun. The resulting movie looks like it came from an alien solar system. The fantastically-colored star is our own sun as STEREO sees it in four wavelengths of extreme ultraviolet light. The black disk is the Moon. When we observe a lunar transit from Earth, the Moon appears to be the same size as the sun, a coincidence that produces intoxicatingly beautiful solar eclipses. The silhouette STEREO-B saw, on the other hand, was only a fraction of the Sun. The Moon seems small because of the STEREO-B location. The spacecraft circles the sun in an Earth-like orbit, but it lags behind Earth by one million miles. This means STEREO-B is 4.4 times further from the Moon than we are, and so the Moon looks 4.4 times smaller. This version of the STEREO-B eclipse movie is a composite of data from the coronagraph and extreme ultraviolet imager of the spacecraft. STEREO-B has a sister ship named STEREO-A. Both are on a mission to study the sun. While STEREO-B lags behind Earth, STEREO-A orbits one million miles ahead ('B' for behind, 'A' for ahead). The gap is deliberate as it allows the two spacecraft to capture offset views of the sun. Researchers can then combine the images to produce 3D stereo movies of solar storms. The two spacecraft were launched in Oct. 2006 and reached their stations on either side of Earth in January 2007.

  18. The 1st of April 2470 BC Total Solar Eclipse Seen by the Prophet Ibraheem

    Science.gov (United States)

    Yousef, S. M.

    The Holy Quran describes a phenomenon seen by young Abraham that can only fit a solar eclipse. Two criteria were given for this particular eclipse; first only one planet was seen as soon as it got dark and second no corona was seen. In order to justify the first selection rule, examinations of solar and planetary longitudes for total solar eclipses passing over Babel were carried out. Only the eclipse of the 1st of April 2470 BC meets this condition, as it was only Venus that was seen at that eclipse. The second selection rule was also naturally fulfilled, as Babel happened to be on the border of the totality zone hence no corona was seen, however all the time the moon glistened as Baily's beads. There is no doubt that the prophet Abraham witnessed the 1st of April total solar eclipse that passed over Babel. This will put him about 470 years backward than it was previously anticipated.

  19. Report about the Solar Eclipse on August 11, 1999

    Science.gov (United States)

    1999-08-01

    Clip (2425 frames/01:37 min) [MPEG Video; 160x120 pix; 2.2M] [MPEG Video; 320x240 pix; 4.4Mb] [RealMedia; streaming; 33kps] [RealMedia; streaming; 200kps] This Video Clip was prepared from a "reportage" of the event at the ESO HQ that was transmitted in real-time to ESO-Chile via ESO's satellite link. It begins with some sequences of the first partial phase and the eclipse watchers. Clouds move over and the landscape darkens as the phase of totality approaches. The Sun is again visible at the very moment this phase ends. Some further sequences from the second partial phase follow. Produced by Herbert Zodet. Dire Forecasts The weather predictions in the days before the eclipse were not good for Munich and surroundings. A heavy front with rain and thick clouds that completely covered the sky moved across Bavaria the day before and the meteorologists predicted a 20% chance of seeing anything at all. On August 10, it seemed that the chances were best in France and in the western parts of Germany, and much less close to the Alps. This changed to the opposite during the night before the eclipse. Now the main concern in Munich was a weather front approaching from the west - would it reach this area before the eclipse? The better chances were then further east, nearer the Austrian border. Many people travelled back and forth along the German highways, many of which quickly became heavily congested. Preparations About 500 persons, mostly ESO staff with their families and friends, were present at the ESO HQ in the morning of August 11. Prior to the eclipse, they received information about the various aspects of solar eclipses and about the specific conditions of this one in the auditorium. Protective glasses were handed out and it was the idea that they would then follow the eclipse from outside. In view of the pessimistic weather forecasts, TV sets had been set up in two large rooms, but in the end most chose to watch the eclipse from the terasse in front of the cafeteria and

  20. [A New Way to Look Up. Solar Retinopathy Risks and Methods of Prevention Prior to the 2015 Solar Eclipse].

    Science.gov (United States)

    Tsatsos, M; MacGregor, C; Gousia, D; Moschos, M; Detorakis, E

    2017-06-01

    A solar eclipse is an impressive natural phenomenon that was last experienced in Europe in 2006. Last year, on March 20th 2015, a solar eclipse was visible in much of Europe. Solar retinopathy is a recognised potentially sight threatening condition that has been associated with direct or unprotected sun gazing. Public education has been shown to improve behaviour and attitudes that could influence the development of solar retinopathy during an eclipse. We have performed a study through newspapers prior to the 2015 solar eclipse in different European countries, in order to determine the level of public health awareness and attitudes to protection. Methods: 31 online editions of national newspapers were reviewed from six countries where the eclipse was most visible. Solar retinopathy, potential warnings, safe methods of viewing an eclipse and assessment of use and dangers of modern technologies were assessed. Results: All 25 newspapers examined mentioned the solar eclipse and risk to eyesight. Safe methods for viewing the eclipse were discussed in all newspapers. Eclipse eyeglasses were mentioned in 29 of the 31 newspapers reviewed. Children were identified as a high-risk group but advice for children viewing the eclipse varied between countries. Conclusion: Since the solar eclipse of 2006, there has been an increase in the level of education available in the media. Although the safe methods for viewing an eclipse have not changed in recent years, emerging technologies, such as camera phones and the "selfie" trend, have potentially increased the risk of eclipse-associated retinopathy. Georg Thieme Verlag KG Stuttgart · New York.

  1. Tomographic Study of Ionospheric Effects Associated with a Solar Eclipse

    Institute of Scientific and Technical Information of China (English)

    Wu Xiong-bin; Xu Ji-sheng; Ma Shu-ying; Tian Mao

    2003-01-01

    This paper studies the ionospheric effects associ-ated with the solar eclipse of October 24th, 1995 by means of Computerized Ionospheric Tomography (CIT). Since the re-constructed profiles from experimental CIT are sporadically located in time, a time domain interpolation method based onSingular Value Decomposition (SVD) technique is proposed and applied to extract the ionospheric effects. The effects canbe extracted by comparison analysis between the interpolated CIT profiles of the eclipse days and that of the reference day that are time-aligned. A series of figs have been obtained showing the attenuation of photonization effect at low alti-tudes and the weakening of plasma's transportation process athigh altitudes, etc. The photonization effect recovered to nor-mal level soon after the last contact. The maximum electron density diminishing is observed about 2 h after the eclipse maximum and the effects seem vanished in the hours fol-lowed. Analysis on vertical TEC's latitudinal temporal variation gives similar conclusions.

  2. An Airborne Infrared Spectrometer for Solar Eclipse Observations

    Science.gov (United States)

    Samra, Jenna; DeLuca, Edward E.; Golub, Leon; Cheimets, Peter; Philip, Judge

    2016-05-01

    The airborne infrared spectrometer (AIR-Spec) is an innovative solar spectrometer that will observe the 2017 solar eclipse from the NSF/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER). AIR-Spec will image five infrared coronal emission lines to determine whether they may be useful probes of coronal magnetism.The solar magnetic field provides the free energy that controls coronal heating, structure, and dynamics. Energy stored in coronal magnetic fields is released in flares and coronal mass ejections and ultimately drives space weather. Therefore, direct coronal field measurements have significant potential to enhance understanding of coronal dynamics and improve solar forecasting models. Of particular interest are observations of field lines in the transitional region between closed and open flux systems, providing important information on the origin of the slow solar wind.While current instruments routinely observe only the photospheric and chromospheric magnetic fields, AIR-Spec will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. During the total solar eclipse of 2017, AIR-Spec will observe five magnetically sensitive coronal emission lines between 1.4 and 4 µm from the HIAPER Gulfstream V at an altitude above 14.9 km. The instrument will measure emission line intensity, width, and Doppler shift, map the spatial distribution of infrared emitting plasma, and search for waves in the emission line velocities.AIR-Spec consists of an optical system (feed telescope, grating spectrometer, and infrared detector) and an image stabilization system, which uses a fast steering mirror to correct the line-of-sight for platform perturbations. To ensure that the instrument meets its research goals, both systems are undergoing extensive performance modeling and testing. These results are shown with reference to the science requirements.

  3. The search for vulcanoids in the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    ZHAO HaiBin; LU Hao; ZHAORI GeTu; YAO JinSheng; MA YueHua

    2009-01-01

    Interior to Mercury's orbit is a dynamically stable region where a population of small, asteroid-like bodies called Vuicanoids has been hypothesized to reside. The Vulcanoid Zone (VZ) extends inward from about 0.18 au to about 0.08 au. During the Total Solar Eclipse (TSE) in 2008, a search for Vul-canoids was completed. Although no Vulcanoids was detected to a moving object detection limit of V=12.8, the search was far more comprehensive than previous searches.

  4. The search for vulcanoids in the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Interior to Mercury’s orbit is a dynamically stable region where a population of small, asteroid-like bodies called Vulcanoids has been hypothesized to reside. The Vulcanoid Zone (VZ) extends inward from about 0.18 au to about 0.08 au. During the Total Solar Eclipse (TSE) in 2008, a search for Vulcanoids was completed. Although no Vulcanoids was detected to a moving object detection limit of V=12.8, the search was far more comprehensive than previous searches.

  5. The ancient Chinese solar eclipse records and the secular changes in the rotation of the earth.

    Science.gov (United States)

    Zhang, Peiyu

    1994-03-01

    This paper discusses and analyses the ancient Chinese solar eclipse records (before the end of Ming Dynasty) in the literature. The author selects thirteen total (annular) solare eclipse records with explicit places of observation from these data and probes into the tendency of secular changes in the rotation of the earth.

  6. Statistical study of the solar eclipses over Egypt during 20 centuries (1–2000

    Directory of Open Access Journals (Sweden)

    H.I. Abdel-Rahman

    2017-06-01

    The General Linear Trend formula for predicting the future values for every types of solar eclipse was obtained and determined during next 500 years (2001–2500. We compare our results with calculated once by NASA for each types of solar eclipse. Our results are in a good agreement with that published by NASA.

  7. An Ancient Solar Eclipse Record "Tian-da-yi" in the 10th Century BC

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The ancient record "Tian-da-yi" (the sky darkened greatly) is identified with the solar eclipse on May 31, 976BC. This identification is demonstrated in this paper through a palaeographic, astronomical and chronological analysis. It is probably the earliest solar eclipse in Chinese history that can be so identified.

  8. Predicting the Structure of the Solar Corona During the December 4, 2002 Total Solar Eclipse

    Science.gov (United States)

    Mikic, Zoran; Linker, Jon A.; Riley, Pete; Lionello, Roberto

    2003-01-01

    The solar magnetic field plays a key role in determining coronal. The principal input to MHD models is the observed solar magnetic field. 3D MHD models can be used to compare with eclipse and coronograph images, SOHO images (LOSCO, EIT), Ulysses and WIND spacecraft data, and interplanetary scintillation (IPS) measurements. MHD computations can tell us about the structure of the corona. Eclipses can help us to verify the accuracy of the models. 4 December, 2002 total eclipce: visible in the southern hemisphere (South Atlantic, southern Africa, Indian Ocean, and Australia). Total in center Angola is at 06:00 UT.

  9. Spectral variation of the solar radiation during an eclipse

    Directory of Open Access Journals (Sweden)

    Peter Koepke

    2001-05-01

    Full Text Available The time dependent variation of the spectral extraterrestrial solar flux is modelled for the conditions during a total eclipse. These data are used to calculate irradiance and actinic flux at the Earth’s surface for atmospheric conditions of August 11, 1999 at Weihenstephan. These results are compared with measurements. It is shown, that the spectral composition of solar radiation varies during the eclipse, since solar limb darkening has a spectral dependence. The solar radiation differs from that of a hypothetical sun without limb darkening by up to 30% in the near IR at 1500 nm and 60% in the UV-B at 310 nm. As shown by a comparison of modelling and measurements, this spectral variation has to be taken into account for modelling of UV radiative quantities in the atmosphere and resulting photochemical processes. The effect of broken cloudiness on irradiance and actinic flux and its dependency on wavelength and receiver geometry is explained. Der Verlauf der spektralen extraterrestrischen solaren Strahlung wÄhrend einer Sonnenfinsternis wurde berechnet. Basierend auf diesen Daten, unter BerÜcksichtigung der atmosphÄrischen Bedingungen am 11. August 1999 in Weihenstephan, wurden Globalstrahlung und Aktinischer Fluss am Boden modelliert und mit Messwerten verglichen. Die spektrale Zusammensetzung der Strahlung Ändert sich wÄhrend einer Sonnenfinsternis, bedingt durch die wellenlÄngenabhÄngige Randverdunklung der Sonne. Im Vergleich zu einer hypothetischen Sonne ohne Randverdunklung ist die solare Strahlung im nahen IR um bis zu 30% gemindert und im UVB bei 310 nm um bis zu 60%. Diese spektralen Änderungen sollten bei der Modellierung von Strahlung, z.B. fÜr photochemische Prozesse berÜcksichtigt werden. Dies wurde durch Messung und Modellierung gezeigt. Der Einfluss von Wolken auf gemessene Werte von Globalstrahlung und Aktinischem Fluss wurde untersucht und erklÄrt.

  10. White light coronal structures and flattening during six total solar eclipses

    Directory of Open Access Journals (Sweden)

    B.A. Marzouk

    2016-12-01

    Flattening index is the first quantitative parameter introduced for analyses of the global structure of the solar corona. It varies with respect to the phase of the solar activity and sunspot number. In this paper we study the solar corona during the 1990, 1999, 2006, 2008, 2009 and 2012 total solar eclipses. We obtain flattening coefficients for all the six eclipses by using a new computer program. Our results are in a good agreement with published results.

  11. Effects of the March 2015 solar eclipse on near-surface atmospheric electricity.

    Science.gov (United States)

    Bennett, A J

    2016-09-28

    Measurements of atmospheric electrical and standard meteorological parameters were made at coastal and inland sites in southern England during the 20 March 2015 partial solar eclipse. Clear evidence of a reduction in air temperature resulting from the eclipse was found at both locations, despite one of them being overcast during the entire eclipse. The reduction in temperature was expected to affect the near-surface electric field (potential gradient (PG)) through a reduction in turbulent transfer of space charge. No such effect could be unambiguously confirmed, however, with variability in PG and air-Earth current during the eclipse being comparable to pre- and post-eclipse conditions. The already low solar radiation for this latitude, season and time of day was likely to have contributed to the reduced effect of the eclipse on atmospheric electricity through boundary layer stability. The absence of a reduction in mean PG shortly after time of maximum solar obscuration, as observed during eclipses at lower geomagnetic latitude, implied that there was no significant change in atmospheric ionization from cosmic rays above background variability. This finding was suggested to be due to the relative importance of cosmic rays of solar and galactic origin at geomagnetic mid-latitudes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  12. The ionospheric responses to the 11 August 1999 solar eclipse: observations and modeling

    Directory of Open Access Journals (Sweden)

    H. Le

    2008-02-01

    Full Text Available A total eclipse occurred on 11 August 1999 with its path of totality passing over central Europe in the latitude range 40°–50° N. The ionospheric responses to this eclipse were measured by a wide ionosonde network. On the basis of the measurements of foE, foF1, and foF2 at sixteen ionosonde stations in Europe, we statistically analyze the variations of these parameters with a function of eclipse magnitude. To model the eclipse effects more accurately, a revised eclipse factor, FR, is constructed to describe the variations of solar radiation during the solar eclipse. Then we simulate the effect of this eclipse on the ionosphere with a mid- and low-latitude ionosphere theoretical model by using the revised eclipse factor during this eclipse. Simulations are highly consistent with the observations for the response in the E-region and F1-region. Both of them show that the maximum response of the mid-latitude ionosphere to the eclipse is found in the F1-region. Except the obvious ionospheric response at low altitudes below 500 km, calculations show that there is also a small response at high altitudes up to about 2000 km. In addition, calculations show that when the eclipse takes place in the Northern Hemisphere, a small ionospheric disturbance also appeared in the conjugate hemisphere.

  13. Using the ionospheric response to the solar eclipse on 20 March 2015 to detect spatial structure in the solar corona.

    Science.gov (United States)

    Scott, C J; Bradford, J; Bell, S A; Wilkinson, J; Barnard, L; Smith, D; Tudor, S

    2016-09-28

    The total solar eclipse that occurred over the Arctic region on 20 March 2015 was seen as a partial eclipse over much of Europe. Observations of this eclipse were used to investigate the high time resolution (1 min) decay and recovery of the Earth's ionospheric E-region above the ionospheric monitoring station in Chilton, UK. At the altitude of this region (100 km), the maximum phase of the eclipse was 88.88% obscuration of the photosphere occurring at 9:29:41.5 UT. In comparison, the ionospheric response revealed a maximum obscuration of 66% (leaving a fraction, Φ, of uneclipsed radiation of 34±4%) occurring at 9:29 UT. The eclipse was re-created using data from the Solar Dynamics Observatory to estimate the fraction of radiation incident on the Earth's atmosphere throughout the eclipse from nine different emission wavelengths in the extreme ultraviolet (EUV) and X-ray spectrum. These emissions, having varying spatial distributions, were each obscured differently during the eclipse. Those wavelengths associated with coronal emissions (94, 211 and 335 Å) most closely reproduced the time varying fraction of unobscured radiation observed in the ionosphere. These results could enable historic ionospheric eclipse measurements to be interpreted in terms of the distribution of EUV and X-ray emissions on the solar disc.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  14. A solar twin in the eclipsing binary LL Aqr

    CERN Document Server

    Graczyk, D; Pavlovski, K; Southworth, J; Pietrzynski, G; Maxted, P F L; Konorski, P; Gieren, W; Pilecki, B; Taormina, M; Suchomska, K; Karczmarek, P; Gorski, M; Wielgorski, P

    2016-01-01

    In the course of a project to study eclipsing binary stars in vinicity of the Sun, we found that the cooler component of LL Aqr is a solar twin candidate. This is the first known star with properties of a solar twin existing in a non-interacting eclipsing binary, offering an excellent opportunity to fully characterise its physical properties with very high precision. We used extensive multi-band, archival photometry and the Super-WASP project and high-resolution spectroscopy obtained from the HARPS and CORALIE spectrographs. The spectra of both components were decomposed and a detailed LTE abundance analysis was performed. The light and radial velocity curves were simultanously analysed with the Wilson-Devinney code. The resulting highly precise stellar parameters were used for a detailed comparison with PARSEC, MESA, and GARSTEC stellar evolution models. LL Aqr consists of two main-sequence stars (F9 V + G3 V) with masses of M1 = 1.1949$\\pm$0.0007 and M2=1.0337$\\pm$0.0007 $M_\\odot$, radii R1 = 1.321$\\pm$0.00...

  15. Clear-Sky Probability for the August 21, 2017, Total Solar Eclipse Using the NREL National Solar Radiation Database

    Energy Technology Data Exchange (ETDEWEB)

    Habte, Aron M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Roberts, Billy J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kutchenreiter, Mark C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wilcox, Steve [Solar Resource Solutions, LLC, Lakewood, CO (United States); Stoffel, Tom [Solar Resource Solutions, LLC, Lakewood, CO (United States)

    2017-07-21

    The National Renewable Energy Laboratory (NREL) and collaborators have created a clear-sky probability analysis to help guide viewers of the August 21, 2017, total solar eclipse, the first continent-spanning eclipse in nearly 100 years in the United States. Using cloud and solar data from NREL's National Solar Radiation Database (NSRDB), the analysis provides cloudless sky probabilities specific to the date and time of the eclipse. Although this paper is not intended to be an eclipse weather forecast, the detailed maps can help guide eclipse enthusiasts to likely optimal viewing locations. Additionally, high-resolution data are presented for the centerline of the path of totality, representing the likelihood for cloudless skies and atmospheric clarity. The NSRDB provides industry, academia, and other stakeholders with high-resolution solar irradiance data to support feasibility analyses for photovoltaic and concentrating solar power generation projects.

  16. The Assembled Solar Eclipse Package (ASEP) in Bangka Indonesia during the total solar eclipse on March 9, 2016

    Science.gov (United States)

    Puji Asmoro, Cahyo; Wijaya, Agus Fany Chandra; Dwi Ardi, Nanang; Abdurrohman, Arman; Aria Utama, Judhistira; Sutiadi, Asep; Hikmat; Ramlan Ramalis, Taufik; Suyardi, Bintang

    2016-11-01

    The Assembled Solar Eclipse Package (ASEP) is not only an integrated apparatus constructed to obtain imaging data during solar eclipse, but also it involved sky brightness and live streaming requirement. Main four parts of ASEP are composed by two imaging data recorders, one high definition video streaming camera, and a sky quality meter instrument (SQM) linked by a personal computer and motorized mounting. The parts are common instruments which are used for education or personal use. The first part is used to capture corona and prominence image during totality. For the second part, video is powerful data in order to educate public through web streaming lively. The last part, SQM is used to confirm our imaging data during obscuration. The perfect prominence picture was obtained by one of the data capture using William-Optics F=388mm with Nikon DSLR D3100. In addition, the diamond ring and corona were recorded by the second imaging tool using Sky Watcher F=910mm with Canon DSLR 60D. The third instrument is the Sony HXR MC5 streaming set to be able to broadcast to public domain area via official website. From the SQM, the value of the darkness during totality is quiet similar as a dawn condition. Finally, ASEP was entirely successful and be able to fulfil our competency as educational researcher in university.

  17. The solar eclipse and associated atmospheric variations observed in South Korea on 22 July 2009.

    Science.gov (United States)

    Chung, Yong Seung; Kim, Hak Sung; Choo, Seung Ho

    2010-09-01

    A partial solar eclipse occurred in South Korea on 22 July 2009. It started at 09:30 a.m. and lasted until 12:14 LST with coverage of between 76.8% and 93.1% of the sun. The observed atmospheric effects of the eclipse are presented. It was found that from the onset of the eclipse, solar radiation was reduced by as much as 88.1 approximately 89.9% at the present research centre. Also, during the eclipse, air temperature decreased slightly or remained almost unchanged. After the eclipse, however, it rose by 2.5 to 4.5 degrees C at observed stations. Meanwhile, relative humidity increased and wind speeds were lowered by the eclipse. Ground-level ozone was observed to decrease during the event.

  18. White light coronal structures and flattening during six total solar eclipses

    Science.gov (United States)

    Marzouk, B. A.; Stoeva, P.; Stoev, A.

    2016-12-01

    Solar corona is very important part of the solar atmosphere, which is not available every time and it is very difficult to observe it. From solar corona we can get more information about outer sun layers. Large-scale structure of the solar corona can be studied during total solar eclipses. The structure, shape and brightness of the solar corona significantly change from eclipse to eclipse. They depend on activity of the sun. At maximum solar activity, the corona is very bright and uniform around the solar limb. There are a lot of bright coronal streamers and other active regions on it. During minimum of solar activity the solar corona stretches at the equator and become elliptical. Flattening index is the first quantitative parameter introduced for analyses of the global structure of the solar corona. It varies with respect to the phase of the solar activity and sunspot number. In this paper we study the solar corona during the 1990, 1999, 2006, 2008, 2009 and 2012 total solar eclipses. We obtain flattening coefficients for all the six eclipses by using a new computer program. Our results are in a good agreement with published results.

  19. The Eclipse, the Astronomer and His Audience: Frederico Oom and the Total Solar Eclipse of 28 May 1900 in Portugal

    Science.gov (United States)

    Carolino, Luis Miguel; Simoes, Ana

    2012-01-01

    This study offers a detailed analysis of an episode of the popularization of astronomy which took place in Portugal, a peripheral country of Europe, and occurring in the early twentieth century. The episode was driven by the 28 May 1900 total solar eclipse which was seen on the Iberian Peninsula (Portugal and Spain). Instead of focusing on one of…

  20. The Eclipse, the Astronomer and His Audience: Frederico Oom and the Total Solar Eclipse of 28 May 1900 in Portugal

    Science.gov (United States)

    Carolino, Luis Miguel; Simoes, Ana

    2012-01-01

    This study offers a detailed analysis of an episode of the popularization of astronomy which took place in Portugal, a peripheral country of Europe, and occurring in the early twentieth century. The episode was driven by the 28 May 1900 total solar eclipse which was seen on the Iberian Peninsula (Portugal and Spain). Instead of focusing on one of…

  1. Search for possible solar neutrino radiative decays during total solar eclipses

    CERN Document Server

    Cecchini, S; Giacomelli, G; Giacomelli, R; Popa, V

    2006-01-01

    Total solar eclipses (TSEs) offer a good opportunity to look for photons produced in possible radiative decays of solar neutrinos. In this paper we briefly review the physics bases of such searches as well as the existing limits on the neutrino proper lifetimes obtained by such experiments. We the report on the observations performed in occasion of the 29 March 2006 TSE, from Waw an Namos, Libya.

  2. Books and Other Resources for Education about the August 21, 2017, Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay M.; Fraknoi, Andrew; Kentrianakis, Michael

    2017-06-01

    As part of our work to reach and educate the 300+ million Americans of all ages about observing the August 21 solar eclipse, especially by being outdoors in the path of totality but also for those who will see only partial phases, we have compiled annotated lists of books, pamphlets, travel guides, websites, and other information useful for teachers, students, and the general public and made them available on the web, at conferences, and through webinars. Our list includes new eclipse books by David Barron, Anthony Aveni, Frank Close, Tyler Nordgren, John Dvorak, Michael Bakich, and others. We list websites accessible to the general public including those of the International Astronomical Union Working Group on Eclipses (http://eclipses.info, which has links to all the sites listed below); the AAS Eclipse 2017 Task Force (http://eclipse2017.aas.org); NASA Heliophysics (http://eclipse.nasa.gov); Fred Espenak (the updated successor to his authoritative "NASA website": http://EclipseWise.com); Michael Zeiler (http://GreatAmericanEclipse.com); Xavier Jubier (http://xjubier.free.fr/en/site_pages/solar_eclipses/); Jay Anderson (meteorology: http://eclipsophile.com); NASA's Eyes (http://eyes.nasa.gov/eyes-on-eclipse.html and its related app); the Astronomical Society of the Pacific (http://www.astrosociety.org/eclipse); Dan McGlaun (http://eclipse2017.org/); Bill Kramer (http://eclipse-chasers.com). Specialized guides include Dennis Schatz and Andrew Fraknoi's Solar Science for teachers (from the National Science Teachers Association:http://www.nsta.org/publications/press/extras/files/solarscience/SolarScienceInsert.pdf), and a printing with expanded eclipse coverage of Jay Pasachoff's, Peterson Field Guide to the Stars and Planets (14th printing of the fourth edition, 2016: http://solarcorona.com).A version of our joint list is to be published in the July issue of the American Journal of Physics as a Resource Letter on Eclipses, adding to JMP's 2010, "Resource Letter SP

  3. Analysis of ionospheric irregularities during total solar eclipse 2016 based on GNSS observation

    Science.gov (United States)

    Husin, A.; Jiyo; Anggarani, S.; Ekawati, S.; Dear, V.

    2016-11-01

    A total solar eclipse occurred over Indonesia in the morning hours on 9 March 2016. Ionisations in the ionosphere which is associated with the solar radiation during the total eclipse provided a good opportunity to study the ionospheric irregularities. Using global navigation satellite system (GNSS) data taken from dual-frequency receivers in Manado, we investigated and analysed the total electron content (TEC) perturbations with a time resolution of 60 s to reveal ionospheric irregularities during total eclipse. Result showed that TEC conditions based on IPP were decreased during solar eclipse on March 9, comparing with the neighbour day. The maximum percentage deviation (DTEC) from the average value during eclipse period, 00:00 - 02:40 UT reach -41.5%. The duration of maximum decrement in TEC occurs were around 2-30 minutes after the maximum obscuration.

  4. Effect of January 15, 2010 annular solar eclipse on meteorological parameters over Goa, India

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.; Nisha, P.G.; Mohankumar, K.

    of annular eclipse and such fluctuation can cause warming in the upper troposphere. A downdraft at the tropopause height in tune with the fluctuation in tropopause could support the movement of stratospheric ozone from the lower stratosphere that can cause...-meteorological measurements in Nigeria during the total solar eclipse of 29 March, 2006. J. Atmos. Solar-Terr. Phys. 71, 1245 – 1253. Nishanth, T., Narendra Ojha, Satheesh Kumar, M.K., Manish Naja, 2011. Infulence of solar eclipse of 15 January 2010 on surface ozone...

  5. TEC variations over Europe during the solar eclipse of March 20, 2015 using GLONASS observations

    Science.gov (United States)

    Shagimuratov, Irk; Cherniak, Iurii; Krankowski, Andrzej; Zakharenkova, Irina; Yakimova, Galina; Tepenitzina, Nadezhda

    2016-07-01

    We report the features of the ionospheric TEC variations derived from the GLONASS measurements during the partial solar eclipse of March 20, 2015. Over Europe the maximal phase of the eclipse was observed around 10 UT. The eclipse took place during period when the ionosphere changed from night to day conditions. This eclipse occurred on the recovery phase of the strong geomagnetic storm of March 17, 2015. The effect of the eclipse was detected in diurnal variations of TEC over the individual GNSS stations as a trough-like variation with a gradual decrease and a succeeding increase of TEC at the time of the eclipse. The eclipse effect on the TEC distribution was observed more distinctly along individual satellite passes. Over the Kaliningrad GNSS station (54N, 20E) we registered the maximal TEC depression of about 4-6 TECU along several satellite passes. We should note that analysis of the ionospheric effects of the solar eclipse was complicated by the geomagnetic storm of March 17. The superposition of the storm and the eclipse make it difficult to separate the absolute TEC changes caused by the eclipse. At the same time the strong changes of the spatial structure of the TEC distribution were registered on the TEC maps. To analyze the spatial TEC distribution during the eclipse the TEC maps with high spatial-temporal resolution were produced. We used the GLONSS measurements derived from 150-180 stations of the dense European GNSS network. Dynamics of the ionospheric plasma density was analyzed using the mixture GLONASS-GPS TEC maps produced with 5 min sampling rate. The spatial structure of the ionosphere changed essentially during the eclipse comparing with the control days. The occurred TEC gradients were quite different comparing with previous and subsequent days. The complex pattern in the spatial-temporal TEC distribution highlights the important role of the dynamic processes in the ionosphere during the eclipse.

  6. Tracking the Ionospheric Response to the Solar Eclipse of November 03, 2013

    Directory of Open Access Journals (Sweden)

    Emirant Bertillas Amabayo

    2014-01-01

    Full Text Available The ionospheric dynamics is highly influenced by the solar radiation. During a solar eclipse, the moon occults the solar radiation from reaching the ionosphere, which may drastically affect the variability of the ionosphere. The variability of total electron content (TEC observed by dual frequency Global Positioning System (GPS receivers has made it possible to study effects of solar eclipse on the ionosphere. Total eclipse occurred on November 03, 2013, and the maximum amplitude was visible at Owiny in northern Uganda. Ionospheric behavior during this eclipse was analysed by using TEC data archived at Mbarara (MBAR, Malindi (MAL2, Eldoret (MOIU, and Kigali University (NURK International GPS Satellite (IGS stations. TEC variations of four consecutive days were used to study instantaneous changes of TEC during the eclipse event. The results generally show TEC decrease at the four stations. However, a maximum perturbation amplitude of ≥20 TECU was observed at MAL2 (18:00–20:00 UT which is further south of the equator than the other stations. TEC enhancement and depletion were observed during the totality of the eclipse at MOIU, MBAR, NURK, and MAL2 (13:00–15:00 UT. This study found out that the ionospheric TEC over East Africa was modified by wave-like energy and momentum transport and obscuration of the solar disc due to the total solar eclipse.

  7. Variation of incoming solar radiation flux during a partial eclipse episode: an improved model simulation

    CERN Document Server

    Petkov, Boyan; Vitale, Vito; Lanconelli, Christian; Mazzola, Mauro

    2011-01-01

    Model simulations of solar irradiance reaching the Earth's surface during a solar eclipse constitute a useful tool for studying the impact of this phenomenon on the radiance propagation through the atmosphere. A simple approach to extend the use of an algorithm already adopted for evaluating the variations in the extraterrestrial solar radiation during a total eclipse is proposed for a partial eclipse case. The application is based on the assessment of the distance between the apparent solar and lunar disk centers on the celestial hemisphere, using the local circumstances and the ratio between the Sun and Moon radii as input parameters. It was found that during the eclipse of March 29, 2006, the present approach led to an estimate of the surface UV solar irradiance trend differing by no more than \\pm5% from the corresponding trend observed at Bologna (Italy).

  8. Using the Solar Eclipse to Estimate Earth's Distance from the Moon.

    Science.gov (United States)

    Sawicki, Mikolaj

    1996-01-01

    Discusses the reasoning behind the determination of the distance from Earth to the Moon by the Greek philosopher Aristarchus upon observing a lunar eclipse. Presents calculations for estimating Earth's distance from the Moon using simple observations made during a solar eclipse. (JRH)

  9. Using the Solar Eclipse to Estimate Earth's Distance from the Moon.

    Science.gov (United States)

    Sawicki, Mikolaj

    1996-01-01

    Discusses the reasoning behind the determination of the distance from Earth to the Moon by the Greek philosopher Aristarchus upon observing a lunar eclipse. Presents calculations for estimating Earth's distance from the Moon using simple observations made during a solar eclipse. (JRH)

  10. The observation of total solar eclipse in Indonesia on 11 June 1983.

    Science.gov (United States)

    Shimizu, Y.; Miyazaki, H.; Imai, H.; Hiei, E.

    The total solar eclipse on 11 June 1983 was observed at Cepu, Central Java. The planning, observing instruments, setting-up and the observing procedure are described. Electron number density in thread-like fine structures in an active region of the corona was derived to be about 5×109 from the corona taken at the eclipse.

  11. RGB color photometry of the solar corona from total solar eclipses

    Science.gov (United States)

    Shopov, Y. Y.; Varonov, A.; Stoykova, D. A.

    2016-02-01

    In the following article we present some of our results from observations of two total solar eclipses (TSE). By combining appropriate photographic equipment and post-processing techniques we show that numerous solar phenomena can be captured in details during TSE. We use color slide RGB photometry technique to visualize invisible regions of the solar corona and to highlight some of the solar phenomena that are very difficult for observation by Earth-based observatories. In fact it reveals more details of the far solar corona than any original image taken from ground-based observations. RGB photometry visualizes different components of the solar corona in one image, which is impossible using conventional observations. This makes it valuable tool for studies of the solar corona. Here we first observe peculiar near infrared emission regions around the upper part of the solar limb during the 1999 TSE. So far its origin is unknown and they need further studies including observations during other solar eclipses. Our observational experiment was designed for other purposes and their registration was completely unexpected.

  12. ON THE COMBINATION OF IMAGING-POLARIMETRY WITH SPECTROPOLARIMETRY OF UPPER SOLAR ATMOSPHERES DURING SOLAR ECLIPSES

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Z. Q.; Deng, L. H.; Dun, G. T.; Chang, L.; Zhang, X. Y.; Cheng, X. M.; Qu, Z. N.; Xue, Z. K.; Ma, L. [Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan 650011 (China); Allington-Smith, J.; Murray, G. [Center for Advanced Instrumentation, University of Durham (United Kingdom)

    2013-09-01

    We present results from imaging polarimetry (IP) of upper solar atmospheres during a total solar eclipse on 2012 November 13 and spectropolarimetry of an annular solar eclipse on 2010 January 15. This combination of techniques provides both the synoptic spatial distribution of polarization above the solar limb and spectral information on the physical mechanism producing the polarization. Using these techniques together we demonstrate that even in the transition region, the linear polarization increases with height and can exceed 20%. IP shows a relatively smooth background distribution in terms of the amplitude and direction modified by solar structures above the limb. A map of a new quantity that reflects direction departure from the background polarization supplies an effective technique to improve the contrast of this fine structure. Spectral polarimetry shows that the relative contribution to the integrated polarization over the observed passband from the spectral lines decreases with height while the contribution from the continuum increases as a general trend. We conclude that both imaging and spectral polarimetry obtained simultaneously over matched spatial and spectral domains will be fruitful for future eclipse observations.

  13. Influence of Partial Solar Eclipse on the Radio Signal during 9 March 2016

    Directory of Open Access Journals (Sweden)

    Nur Zulaikha Mohd Afandi

    2017-04-01

    Full Text Available The occasion of the partial solar eclipse in Malaysia occurred on 9th March 2016 covered almost 60% to 90% of the whole Sun. During the maximum time of partial solar eclipse, some of the solar radiations and sunlight was blocked to reach the Earth’s surface. In order to see this effect to a radio signal, the analysis of radio signal pattern before and during solar eclipse at Balai Cerap KUSZA, Merang, Terengganu was done. The radio signal measurement was taken in the wideband frequency region from 0Hz to 9GHz. The radio signal data had been analysis to compare between before and during the eclipse by calculating their average.Initial analysis shows that there a different number of peak signal between two observations. Then, the solar radiation data during the partial solar eclipse also was analysed. Furthermore, solar events data from National Oceanic and Atmospheric Administration (NOAA also added into this work. It shows that there not enough prove that the partial solar eclipse affect the radio signal pattern.

  14. Color Portion of Solar Radiation in the Partial Annular Solar Eclipse, October 3rd, 2005, at Helwan, Egypt

    Directory of Open Access Journals (Sweden)

    A. H. Hassan

    2010-01-01

    Full Text Available Measurements were made of various solar radiation components, global, direct and diffuse and their fractions during the partial annular solar eclipse on October 3rd, 2005 at Helwan, Egypt (Lat. 29.866◦ N and Long. 31.20◦ E, and an analysis has been made. The duration of the solar eclipse was 3 h 17 min, and the maximum magnitude of the eclipse in this region was 0.65. The optical depth of the direct component and the relative humidity decreased, while both the transparency and the air temperature increased towards the maximum eclipse. The general trends of the global components are decreasing optical depth and increasing transparency between the first contact and the last contact. The prevailing color during the eclipse duration was diffused infrared (77 % of the total diffuse radiation level.

  15. Color Portion of Solar Radiation in the Partial Annular Solar Eclipse, October 3rd, 2005, at Helwan, Egypt

    OpenAIRE

    A. H. Hassan; U. A. Rahoma; Sabry, M; A. M. Fathy

    2010-01-01

    Measurements were made of various solar radiation components, global, direct and diffuse and their fractions during the partial annular solar eclipse on October 3rd, 2005 at Helwan, Egypt (Lat. 29.866◦ N and Long. 31.20◦ E), and an analysis has been made. The duration of the solar eclipse was 3 h 17 min, and the maximum magnitude of the eclipse in this region was 0.65. The optical depth of the direct component and the relative humidity decreased, while both the transparency and the air temper...

  16. Outreach activities in anticipation of the 2016 solar eclipse in Sorong

    Science.gov (United States)

    Putra Raharja, Endra; Pramudya, Yudhiakto

    2016-11-01

    Sorong is located outside the narrow path of total solar eclipse on March 9th, 2016. The predicted obscuration of the sun was 94.2%. The public outreach to anticipate the solar eclipse was intended to educate students in junior and senior high school in Sorong Regency. Some of them are located in the remote area where the educational materials are difficult to find. The public outreach is unique, since it was run by the local person who is student of physics education. The student has both the ability to explain the solar eclipse phenomenon and able to adapt to knowledge level of students. The materials that were given to the schools are brochure and the eclipse glasses. Beside solar eclipse lectures in class, the pinhole workshop and observation practice were held. The limited materials and resources were faced during the public outreach. However, the enthusiasm was shown by the students and teachers. At least one of the schools held the solar eclipse observation on the day of the eclipse.

  17. On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse.

    Science.gov (United States)

    Marlton, G J; Williams, P D; Nicoll, K A

    2016-09-28

    Internal gravity waves are generated as adjustment radiation whenever a sudden change in forcing causes the atmosphere to depart from its large-scale balanced state. Such a forcing anomaly occurs during a solar eclipse, when the Moon's shadow cools part of the Earth's surface. The resulting atmospheric gravity waves are associated with pressure and temperature perturbations, which in principle are detectable both at the surface and aloft. In this study, surface pressure and temperature data from two UK sites at Reading and Lerwick are examined for eclipse-driven gravity wave perturbations during the 20 March 2015 solar eclipse over northwest Europe. Radiosonde wind data from the same two sites are also analysed using a moving parcel analysis method, to determine the periodicities of the waves aloft. On this occasion, the perturbations both at the surface and aloft are found not to be confidently attributable to eclipse-driven gravity waves. We conclude that the complex synoptic weather conditions over the UK at the time of this particular eclipse helped to mask any eclipse-driven gravity waves.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  18. SPECIAL SEMINAR - The NOTTE experiment, or how to become a Total Solar Eclipse chaser

    CERN Document Server

    CERN. Geneva

    2007-01-01

    The seminar will be followed by a brief presentation of future camps for solar eclipse chasers and scientists organized in 2008 in Russia, Kazakhstan, China and Mongolia, in 2009 in Shanghai and on the Easter Island in 2010.

  19. Chromosomal aberrations found in Paracalanus aculeatus (Giesbrecht) at the time of solar eclipse

    Digital Repository Service at National Institute of Oceanography (India)

    Goswami, U.; Goswami, S.C.

    Chromosomal aberrations in the form of an unequal heteromorphic homologous pair and a supernumerary chromosome were observed in the gonad of a copepod - @iParacalanus aculeatus@@ after being exposed to the total solar eclipse of Feb. 16, 1980...

  20. Identification of moon craters and solar corona during total solar eclipse on 9th March 2016

    Science.gov (United States)

    Luthfiandari; Ekawanti, N.; Purwati, F. G.; Herdiwijaya, D.

    2016-11-01

    Total Solar Eclipse (TSE) is a rare natural event in which the positions of Sun, Moon, and Earth are perfectly aligned. In the past by using this phenomenon, many researches have been done to understand characteristic of the corona. In this paper we carried out the study of TSE which crossed over Indonesia from West to East on 9th March 2016. We observed TSE which occured in Palembang (2.9883° S 104.7513° E), Indonesia. The aim of this research is to understand the effect of moon craters on the appearance of solar corona and identification of solar active regions during TSE. This research was done using Canon SX170 IS camera with ND 5 sun-filter. Although the sky was cloudy during the totality of the phase, coronal video was still taken. Camera also took solar images of partial eclipse phase. Coronal images for every frame were then extracted from the video. Image processing of coronal images was done using RegiStax and PhotoScape freewares. To study solar corona, images from Virtual Moon Atlas, Hinode XRT, and SOHO-LASCO were compared with the result of oriented coronal image. Wider and many more moon craters were found having positive correlation with the brighter effect on solar corona as shown at westward coronal streamer. Those craters are represented by Bel'kovich crater, the biggest one. We also found that only the eastward coronal streamer was correlated with active region, sunspot number 12519, from behind solar limb.

  1. Observing the 2017 Total Solar Eclipse from the Pisgah Astronomical Research Institute

    Science.gov (United States)

    Kirwan, Sean Matthew; Cline, J. Donald; Krochmal, Mark; Donald Cline, Mark Krochmal

    2017-01-01

    The Pisgah Astronomical Research Institute (PARI) is located directly under the path of totality of next year’s solar eclipse and possesses two 26m radio telescopes capable of interferometry at simultaneously at 2.3 GHz and 8.4 GHZ. PARI is preparing these radio telescopes for use by the astronomical community to observe solar eclipse. We will present the status of PARI’s radio telescopes and information on access for the eclipse. We will also present the status and availability of several optical telescopes.

  2. Effects of total solar eclipse on mental patients-a clinicobiochemical correlation.

    Science.gov (United States)

    Boral, G C; Mishra, D C; Pal, S K; Ghosh, K K

    1981-04-01

    Thirteen treated psychotic cases comprising of eight schizophrenic, four M.D.P. (manic type) and one M. D. P. (depressive type), who were clinically symptom free, were studied in respect of their hormones and behavioural abnormalities under effect of total solar eclipse. Of the hormones studied viz., T(2), T(4), TSH, Cortisol and prolactin, it is prolactin which showed an increase in titre associated with behavioural abnormalities in concerned patients during and immediately after the total solar eclipse. Deflection in both prolactin and behaviour gradually seemed to normalise over the post eclipse period.

  3. The Measurement of Solar Diameter and Limb Darkening Function with the Eclipse Observations. Thesis work

    CERN Document Server

    Raponi, Andrea

    2013-01-01

    A discussion of the solar diameter and its variations must be linked to the limb darkening function (LDF). We introduce a new method to perform high resolution astrometry of the solar diameter from the ground, through the observations of eclipses, using the luminosity evolution of Baily's Bead and the profile of the lunar edge available from satellite data. The method proposed is applied for the videos of the eclipse on 15 January 2010 recorded in Uganda and in India. We obtained a detailed profile constraining the inflection point position. The result suggests reconsidering the evaluations of the historical eclipses observed with a naked eye.

  4. The 2008 August 1 Eclipse Solar-Minimum Corona Unraveled

    CERN Document Server

    Pasachoff, Jay M; Druckmuller, Miloslav; Aniol, Peter; Saniga, Metod; Minarovjech, Milan

    2009-01-01

    We discuss results stemming from observations of the white-light and [Fe XIV] emission corona during the total eclipse of the Sun of 2008 August 1, in Mongolia (Altaj region) and in Russia (Akademgorodok, Novosibirsk, Siberia). Corresponding to the current extreme solar minimum, the white-light corona, visible up to 20 solar radii, was of a transient type with well-pronounced helmet streamers situated above a chain of prominences at position angles 48, 130, 241 and 322 degrees. A variety of coronal holes, filled with a number of thin polar plumes, were seen around the poles. Furthering an original method of image processing, stars up to 12 magnitude, a Kreutz-group comet (C/2008 O1), and a coronal mass ejection (CME) were also detected, with the smallest resolvable structures being of, and at some places even less than, 1 arcsec. Differences, presumably motions, in the corona and prominences are seen even with the 19-min time difference between our sites. In addition to the high-resolution coronal images, whi...

  5. The Role of Solar Eclipses in El Nino/La Nina Events

    Science.gov (United States)

    Chiu, B. C.

    2005-08-01

    The first hint of the fact that solar eclipses mark the enhanced storms called El Nino or La Nina, came from the article by Robert Allan on analysis of frequencies of these events (2001, perhaps Fourier analysis). One mystery was the cause of a cycle with period 15 to 20 years. But the Saros Series of solar eclipses has a period of 18+ years. Then we had the data from Galapagos Islands for the whole 20th century (Philander 2004). The graph of high and low temperatures indicates El Ninos and La Ninas. A search through charts of solar eclipses for those with good locations for bringing high tides at the Tropics, gave a good picture: those at the eastern coast of the pacific Ocean gave El Ninos, and those at the west gave La Ninas. More than half of the peaks and troughs on the temperature graph can be identified with solar eclipses. We looked more closely at a few events that caused great storms. They are described in J. M. Nash's book, ``El Nino" (2002). The most striking case is that of the 1998 Feb. 22 solar eclipse, which corresponds to the so-called El Nino of 1997-98. In conclusion, I would say that the annual El nino effect is due to the sun's travel between the Tropic of Cancer and Tropic of Capricorn. But the enhanced El Niino/La Nina is due to the coming together of sun and moon in the solar eclipses, which seem to come irregularly.

  6. Perception of Solar Eclipses Captured by Art Explains How Imaging Misrepresented the Source of the Solar Wind

    OpenAIRE

    2015-01-01

    The visible corona revealed by the natural phenomenon of solar eclipses has been studied for 150 years. A turning point has been the discovery that the true spatial distribution of coronal brightness can neither be seen nor imaged on account of its unprecedented dynamic range. Howard Russell Butler (1856–1934), the painter of solar eclipses in the early 20th century, possessed the extraordinary skill of painting from memory what he saw for only a brief time. His remarkable but forgotten eclip...

  7. The effect of total solar eclipse on the daily activities of Nasalis larvatus (Wurmb.) in Mangrove Center, Kariangau, East Kalimantan

    Science.gov (United States)

    Sya Shanida, Sya; Hanik Lestari, Tiffany; Partasasmita, Ruhyat

    2016-11-01

    The total solar eclipse is an interesting phenomenon because the sun is covered by the moon. This phenomenon is like a night deception for animals, humans, and plants. One of the animals is Bekantan (Nasalis larvatus (Wurmb.)). Nasalis larvatus change its activity when this phenomenon occurs. The aims of the present study are (1) daily activity of Nasalis larvatus on total solar eclipse on March 9th, 2016 and (2) the effect of total solar eclipse on its activity in Mangrove Center, Kariangau, East Kalimantan. The adlibitum method was used in this study on Bekantan's adult female. The result shows that the total solar eclipse has considerable effect on the daily activity of Bekantan. During total solar eclipse, the activity of Bekantan significantly stopped. When the total solar eclipse finished, Bekantan started its daily activity, and it was indicated by feeding activity which was led by alfa-male.

  8. Micro-gravity measurements during the total solar eclipse of 9 March 2016 in Indonesia

    Science.gov (United States)

    Laesanpura, Agus; Hidayat, Taufiq; Abdurachman, Dady; Mahasena, Putra; Premadi, Premana W.; Wulandari, Hesti; Suharyadi, Yudi; Sjarmidi, Achmad

    2016-11-01

    Since 1950s, several authors have reported the so-called anomalous gravity during the total solar eclipses through various experiments. To address this issue, in the moment of the total solar eclipse of 9 March 2016 passing most regions in Indonesia, we undertook microgravity measurements using two precise gravimeters. The measurements were made at two locations: (1) Poso (central Sulawesi), a location close to the centre passage of the total eclipse and (2) Lembang (West Java), the site of Bosscha Observatory, where the partial solar eclipse occurred. The two sites are selected to measure the possible different influence of the eclipse on aligning the three objects. The measurements were recorded three days before and one day after the eclipse at various intervals from 30 seconds to a short time at 5 seconds. The finer recording was performed several hours before and after the total eclipse. This measurement allowed detailed analysis, not only in time but also in frequency range. A detailed analysis is presented in this paper. We consider all possible geophysical as well as atmospheric effects. The residual data show that the shielding effect, usually thought as responsible factor on anomalous gravity, is not significant.

  9. On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse

    Science.gov (United States)

    2016-01-01

    Internal gravity waves are generated as adjustment radiation whenever a sudden change in forcing causes the atmosphere to depart from its large-scale balanced state. Such a forcing anomaly occurs during a solar eclipse, when the Moon’s shadow cools part of the Earth’s surface. The resulting atmospheric gravity waves are associated with pressure and temperature perturbations, which in principle are detectable both at the surface and aloft. In this study, surface pressure and temperature data from two UK sites at Reading and Lerwick are examined for eclipse-driven gravity wave perturbations during the 20 March 2015 solar eclipse over northwest Europe. Radiosonde wind data from the same two sites are also analysed using a moving parcel analysis method, to determine the periodicities of the waves aloft. On this occasion, the perturbations both at the surface and aloft are found not to be confidently attributable to eclipse-driven gravity waves. We conclude that the complex synoptic weather conditions over the UK at the time of this particular eclipse helped to mask any eclipse-driven gravity waves. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550763

  10. Public Education Plans for the 2017 August 21 Total Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay M.

    2016-06-01

    A total solar eclipse will cross the continental United States on 2017 August 21, the first such in 99 years and the first whose path of totality on land is entirely in the United States since 1776. People in the rest of the United States-as well as in Canada, Central America, and northern South America-will have a partial solar eclipse. Totality will range up to about 70 km in diameter, and will be visible from a path that extends from Oregon to South Carolina. Cloudiness statistics based on decades on satellite infrared imaging are more favorable for western sites. The sun's diameter will be 80% covered in Miami (south of totality) and New York (north of totality), and 70% covered in Los Angeles (south of totality). For the Working Group on Solar Eclipses of the International Astronomical Union, I maintain a website at http://eclipses.info that provides links to a wide variety of eclipse-related material and to useful websites run by others.Prior to this total eclipse, annular eclipses will cross Africa (from Gabon to Tanzania and Madagascar) and Isle de la Réunion on 2016 September 1, and Chile and Argentina on 2017 February 26, at which time we plan an eclipse workshop in Esquel, Argentina.For the forthcoming 2017 eclipse, we acknowledge grants to JMP and Williams College from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation and from the Committee for Research and Exploration of the National Geographic Society.

  11. Boundary layer photochemistry during a total solar eclipse

    Directory of Open Access Journals (Sweden)

    Peter Fabian

    2001-05-01

    Full Text Available Simultaneous measurements of radiation, photolysis frequencies, O3, CO, OH, PAN and NOx species were carried out in the boundary layer, along with pertinent meteorological parameters, under total solar eclipse conditions. This experiment performed at about 34 solar zenith angle and noontime conditions thus provided a case study about the interactions between radiation and photochemistry under fast ''day-night'' and ''night-day'' transitions, at high solar elevation. The results reveal a close correlation of photolysis frequencies jO(1D and jNO2with the UV radiation flux. All three parameters show, due to the decreasing fraction of direct radiation at shorter wavelengths, much weaker cloud shading effects than global solar radiation. NO and OH concentrations decrease to essentially zero during totality. Subsequently, NO and OH concentrations increased almost symmetrically to their decrease preceding totality. The NO/NO2 ratio was proportional to jNO2over 30 min before and after totality indicating that the partitioning of NOx species is determined by jNO2. Simple box model simulations show the effect of reduced solar radiation on the photochemical production of O3 and PAN. WÄhrend der totalen Sonnenfinsternis am 11. August 1999 wurden simultane und kontinuierliche Messungen von O3, CO, OH, PAN and NOx, Strahlung, Photolysefrequenzen und relevanten meteorologischen Parametern durchgefÜhrt. Dieses Experiment, durchgefÜhrt etwa am Mittag, bei 34 Zenithwinkel der Sonne, ermöglichte die Untersuchung der Interaktion von Strahlung und Photochemie fÜr schnelle Tag-Nacht und Nacht-Tag-ÜbergÄnge bei hohem Sonnenstand. Die Ergebnisse zeigen eine enge Korrelation der Photolysefrequenzen jO(1D und jNO2 mit dem UV-Strahlungsfluss. Alle drei Parameter zeigen, wegen des abnehmenden Anteils direkter Sonnenstrahlung bei kurzen WellenlÄngen, erheblich geringere AbschwÄchung durch Wolken als die Globalstrahlung. NO und OH gehen wÄhrend der

  12. [Analysis of urban thermal environment change characteristics during the total solar eclipse].

    Science.gov (United States)

    Lu, Jun; Chen, Shi-Ling; Bu, Cui-Wen; Liu, Yu-Xi

    2011-04-01

    There was a very good observation area in Chongqing for the total solar eclipse along the Changjiang river on 22 July, 2009. Through the experiments, the outdoor meteorological data (solar radiation, air temperature and relative humidity) were observed and recorded on 21 July and 22 July. Based on the experimental observation data, the effect of thermal environment in Chongqing area was to analyzed and discussed. Experiment indicates that the reduction of air temperature and surface temperature resulted in the decrease in the solar radiation intensity, and the amplitude of the air temperature change is 2.4 degrees C during the total solar eclipse. Compared with the two days' air temperature, the amplitude of the air temperature change reached 4.6 degrees C on account of the total solar eclipse.

  13. Mass motion in upper solar chromosphere detected from solar eclipse observation

    Science.gov (United States)

    Li, Zhi; Qu, Zhongquan; Yan, Xiaoli; Dun, Guangtao; Chang, Liang

    2016-05-01

    The eclipse-observed emission lines formed in the upper solar atmosphere can be used to diagnose the atmosphere dynamics which provides an insight to the energy balance of the outer atmosphere. In this paper, we analyze the spectra formed in the upper chromospheric region by a new instrument called Fiber Arrayed Solar Optic Telescope (FASOT) around the Gabon total solar eclipse on November 3, 2013. The double Gaussian fits of the observed profiles are adopted to show enhanced emission in line wings, while red-blue (RB) asymmetry analysis informs that the cool line (about 104 K) profiles can be decomposed into two components and the secondary component is revealed to have a relative velocity of about 16-45 km s^{-1}. The other profiles can be reproduced approximately with single Gaussian fits. From these fittings, it is found that the matter in the upper solar chromosphere is highly dynamic. The motion component along the line-of-sight has a pattern asymmetric about the local solar radius. Most materials undergo significant red shift motions while a little matter show blue shift. Despite the discrepancy of the motion in different lines, we find that the width and the Doppler shifts both are function of the wavelength. These results may help us to understand the complex mass cycle between chromosphere and corona.

  14. The effects of a solar eclipse on photo-oxidants in different areas of China

    Directory of Open Access Journals (Sweden)

    J.-B. Wu

    2011-01-01

    Full Text Available This study investigates the effects of the total solar eclipse of 22 July 2009 on surface ozone and other photo-oxidants over central China using the WRF-Chem model. Chemical and meteorological observation data were used to validate the model, and results suggest that the WRF-Chem model can capture the effects of the total solar eclipse well. The maximum impacts of the eclipse occur over the area of totality, with a decrease in surface temperature of 1.5 °C and decrease in wind speed of 1 m s−1. In contrast, the maximum impacts on atmospheric pollutants occur over parts of north and east China where emissions are greater, with an increase of 5 ppbv in NO2 and 25 ppbv in CO and a decrease of 10 ppbv in O3 and 3 ppbv in NO. This study also shows the effects of the solar eclipse on surface photo-oxidants in different parts of China. Although the sun was obscured to a smaller extent in polluted areas than in clean areas, the impacts of the eclipse in polluted areas are greater and last longer than they do in clean areas. The change in radical concentrations during the eclipse reveals that nighttime chemistry dominates in both polluted and clean areas. In contrast to the effects on atmospheric pollutants, the change in radical concentrations (OH, HO2 and NO3 in clean areas is much larger than in polluted areas mainly because of the limited sources of radicals in these areas. In addition, since solar eclipse does provide a natural opportunity to test our understanding more thoroughly on atmospheric chemistry, especially on photolysis-related chemistry, a comprehensive experimental campaign is highly recommended during solar eclipses in future.

  15. A Solar Mini-Eclipse on May 7, 2003

    Science.gov (United States)

    2003-06-01

    Planet Mercury Passes in Front of the Solar Disk Summary [Go to Mercury Transit 2003 website] A solar mini-eclipse! On May 7, 2003, Mercury, the innermost planet in the solar system, will pass in front of the Sun and produce a solar eclipse. But this event will hardly be noticed. Mercury's small disk will indeed barely be bigger than the point of a pencil. Even the smallest sunspots on the solar surface are as big as the Earth and measure 10,000 km or more in diameter, while Mercury's equatorial diameter is only 4878 km. Bathed in intense sunlight, this small, hot planet moves around the Sun in an elliptical orbit at a mean distance of only 58 million km, much closer to the Sun than other inner planet, Venus (108 million km) and the Earth (150 million km). The disk of Mercury is very small and will be very difficult to see . A powerful telescope is needed to observe this event and to show clearly how Mercury moves across the solar disk. The disk of Mercury is indeed only 13 arcseconds across (while the solar disk measures about 1800 arcseconds). This corresponds to the size of a 1 EURO coin located at the top of the Eiffel Tower as seen from the ground. Therefore, Mercury will only block 1/20,000th of the Sun's light . ESO PR Photo 11a/03 ESO PR Photo 11a/03 [Normal - JPEG: 600 x 449 pix - 112k] Caption : During the transit on May 7, 2003, Mercury will be seen as a small, black dot on the surface of the Sun. Mercury Transits Passages of Mercury in front of the Sun, or "Mercury Transits" in astronomical terminology, are comparatively rare events , due to the different orbital inclinations of the Earth and Mercury as they move around the Sun. In order for a Mercury transit to happen, the planet must be located directly between the Earth and the Sun and also near one of the two points in its orbit where Mercury's orbital plane intersects that of the Earth. We then face the dark side of Mercury - the hemisphere that is not illuminated by the Sun - and see it as a small

  16. Hybrid solar lighting distribution systems and components

    Science.gov (United States)

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  17. Hybrid solar lighting systems and components

    Science.gov (United States)

    Muhs, Jeffrey D.; Earl, Dennis D.; Beshears, David L.; Maxey, Lonnie C.; Jordan, John K.; Lind, Randall F.

    2007-06-12

    A hybrid solar lighting system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates each component.

  18. Come to Noyon (France) and follow the solar eclipse with ESA

    Science.gov (United States)

    1999-08-01

    ESA will feature a special exhibition stand where the public, amateurs and press can obtain information. During the partial eclipse phases, the latest images from ESA's solar observatory SOHO and from other European eclipse sites, coming via the Internet or traditional broadcast, will be shown on a large video screen. The magic of the total eclipse in Noyon will last 2 minutes and 11 seconds. ESA has set up a multi-site eclipse imaging campaign over Europe to capture a long eclipse sequence from the Atlantic, the UK, France (Noyon and Strasbourg), Germany, Austria/ Hungary (at an international camp of young astronomers) and Romania. High-definition still and video images of the eclipse will be available live on the Internet. Check our site http://sci.esa.int/eclipse99/ Noyon will also host a press briefing at the eclipse site Media Centre at 9h30-10h30, and again at 13h15-14h15, after the eclipse shadow has left Europe. Opportunities for interviews with ESA multi-language staff and other specialists will be possible after the eclipse. Over the week leading up to the eclipse, ESA representatives are also participating in press and public conferences. Daily press conferences are scheduled in Strasbourg at the France 3 Auditorium from 4 to 11 August at 16:00-18:00 hrs, in Paris at the Museum d'Histoire Naturelle from 5 -12 August (except 11 August) at 10:00-12:00 hrs, and in Stuttgart at the Science Fair, where an ESA/Max Plank Institute stand has also been set up.

  19. Simulation of solar radiation during a total eclipse: a challenge for radiative transfer

    Directory of Open Access Journals (Sweden)

    C. Emde

    2007-01-01

    Full Text Available A solar eclipse is a rare but spectacular natural phenomenon and furthermore it is a challenge for radiative transfer modelling. Whereas a simple one-dimensional radiative transfer model with reduced solar irradiance at the top of the atmosphere can be used to calculate the brightness during partial eclipses a much more sophisticated model is required to calculate the brightness (i.e. the diffuse radiation during the total eclipse. The reason is that radiation reaching a detector in the shadow gets there exclusively by horizontal transport of photons in a spherical shell atmosphere, which requires a three-dimensional radiative transfer model. In this study the first fully three-dimensional simulations for a solar eclipse are presented exemplified by the solar eclipse at 29 March 2006. Using a backward Monte Carlo model we calculated the diffuse radiation in the umbra and simulated the changing colours of the sky. Radiance and irradiance are decreased by 3 to 4 orders of magnitude, depending on wavelength. We found that aerosol has a comparatively small impact on the radiation in the umbra. We also estimated the contribution of the solar corona to the radiation under the umbra and found that it is negligible compared to the diffuse solar radiation in the wavelength region from 310 to 500 nm.

  20. Mid-latitude solar eclipses and their influence on ionospheric current systems

    Directory of Open Access Journals (Sweden)

    A. T. Tomás

    2009-12-01

    Full Text Available Using CHAMP magnetic field data we study the behaviour of the geomagnetic field during two mid latitude eclipses on 21 June 2001 and 22 September 2006. The possible influence of the eclipses on different ionospheric current systems, as seen in the magnetic field measured by CHAMP, is discussed. It is expected that the blocking of solar radiation during an eclipse causes a reduction of the ionospheric conductivity and therefore has an effect on the different current systems. We address in particular the effects of the eclipses on the inter-hemispheric field-aligned currents and on the Sq current system. The two events studied occur under different seasonal conditions, e.g. June solstice and September equinox, therefore quite different aspects can be investigated. We find that the eclipses might affect the direction and intensity of the inter-hemispheric currents and possibly influence the direction of zonal winds, therefore changing the direction of the prevailing F-region dynamo currents. The eclipse in the Southern Hemisphere during September equinox caused inter-hemispheric currents similar to those observed in northern summer. Reverse inter-hemispheric currents were recorded after the end of the eclipse. A large variety of atypical currents was observed during the June event. Most of them might be related to a reversed F-region dynamo in the morning sector and an enhanced conductivity difference between the hemispheres. The eclipse in the south seems to enhance the June solstice conditions considerably.

  1. Educational, scientific, tourist and outreach potential of the September 1, 2016 Annular Solar Eclipse in Tanzania

    Science.gov (United States)

    Tayabali Jiwaji, Noorali

    2015-08-01

    Tanzania will witness a major astronomical spectacle of an annular eclipse on September 1, 2016. The central part of the eclipse will pass through southern Tanzania, crossing national parks and game reserves such as Katavi and the world famous Selous. For the rest of Tanzania and neighbouring countries it will be a memorable event with large of the proportion of the Sun being covered up. The climate in Tanzania during September is cool and dry which will provide ideal viewing conditions. Solar eclipse events attract "eclipse chasers" from around the globe.Scientific interest in measuring the properties of the Sun and the effects of the eclipse on the atmosphere will allow local scientists to partner with leading scientists to gain valuable experience and knowledge.Local population's wonder and interest in eclipses can be exploited through public-private partnerships by encouraging students and local people to travel to the central path or to observe from their backyards. Large number of eclipse glasses can be manufactured cheaply using safe solar filters for supplying to students and general population in Tanzania and neigbouring countries. This will raise science awareness about the wonders of our Universe.When combined with the attraction of Tanzania's treasures in the north and the 16 tonne Mbozi meteorite in southern Tanzania, the touristic potential of this event can be exploited through tour packages and worldwide advertisements during the coming year.

  2. Exploring the Physics of the Corona with Total Solar Eclipse Observations

    OpenAIRE

    2011-01-01

    This white paper is a call for a concerted effort to support total solar eclipse observations over the next decade, in particular for the 21 August 2017 eclipse which will traverse the US continent. With the recent advances in image processing techniques and detector technology, the time is ripe to capitalize on the unique diagnostic tools available in the visible and near infrared wavelength range to explore the physics of the corona. The advantage of coronal emission lines in this wavelengt...

  3. Predictions for the total solar eclipse of 1991

    Science.gov (United States)

    Espenak, Fred

    1989-01-01

    A total eclipse of the sun will be widely visible from the Western Hemisphere on July 11, 1991. Detailed predictions for this event are presented which include tables of geographic coordinates for the northern limit, southern limit and center line of the path of totality, local circumstances on the center line and for 95 cities within the partial and total eclipse paths, maps depicting the path of totality, the sky during totality and the lunar limb profile. The author discusses the general characteristics of the eclipse including local circumstances from various points along the central path, the Saros series history and effects caused by the lunar limb profile.

  4. Predictions for the total solar eclipse of 1988

    Science.gov (United States)

    Espenak, Fred

    1987-01-01

    A total eclipse of the sun will be widely visible from the East Indies on March 18, 1988. Detailed predictions for this event are presented which include tables of geographic coordinates for the northern limit, center line and southern limit of the path of totality, local circumstances for 40 cities within the total and partial eclipse paths, the lunar-limb profile, and maps depicting the path of totality. The author discusses the general characteristics of the eclipse, local circumstances from various points along the central path and the Saros-series history.

  5. The effects of a solar eclipse on photo-oxidants in different areas of China

    Directory of Open Access Journals (Sweden)

    J.-B. Wu

    2011-08-01

    Full Text Available This study investigates the effects of the total solar eclipse of 22 July 2009 on surface ozone and other photo-oxidants over China. A box model was used to study the sensitivity of ozone to the limb darkening effect during an eclipse event, and to show that the impact on ozone is small (less than 0.5 %. In addition, the regional model WRF-Chem was applied to study the effects of the eclipse on meteorological and chemical parameters, focusing on different regions in China. Chemical and meteorological observations were used to validate the model and to show that it can capture the effects of the total solar eclipse well. Model calculations show distinct differences in the spatial distributions of meteorological and chemical parameters with and without the eclipse. The maximum impacts of the eclipse occur over the area of totality, where there is a decrease in surface temperature of 1.5 °C and decrease in wind speed of 1 m s−1. The maximum impacts on atmospheric pollutants occur over parts of north and east China where emissions are greater, with an increase of 5 ppbv in NO2 and 25 ppbv in CO and a decrease of 10 ppbv in O3 and 4 ppbv in NO. This study also demonstrates the effects of the solar eclipse on surface photo-oxidants in different parts of China. Although the sun was obscured to a smaller extent in polluted areas than in clean areas, the impacts of the eclipse in polluted areas are greater and last longer than they do in clean areas. In contrast, the change in radical concentrations (OH, HO2 and NO3 in clean areas is much larger than in polluted areas mainly because of the limited source of radicals in these areas. The change in radical concentrations during the eclipse reveals that nighttime chemistry dominates in both clean and polluted areas. As solar eclipses provide a natural opportunity to test more thoroughly our understanding of atmospheric chemistry, especially that

  6. Spectroscopic Coronal Observations during the Total Solar Eclipse of 11 July 2010

    CERN Document Server

    Voulgaris, A G; Seiradakis, J H; Pasachoff, J M; Economou, T E

    2012-01-01

    The flash spectrum of the solar chromosphere and corona was measured with a slitless spectrograph before, after, and during the totality of the solar eclipse, of 11 July 2010, at Easter Island, Chile. This eclipse took place at the beginning of the Solar Cycle 24, after an extended minimum of solar activity. The spectra taken during the eclipse show a different intensity ratio of the red and green coronal lines compared with those taken during the total solar eclipse of 1 August 2008, which took place towards the end of the Solar Cycle 23. The characteristic coronal forbidden emission line of forbidden Fe XIV (5303 {\\AA}) was observed on the east and west solar limbs in four areas relatively symmetrically located with respect to the solar rotation axis. Subtraction of the continuum flash-spectrum background led to the identification of several extremely weak emission lines, including forbidden Ca XV (5694 {\\AA}), which is normally detected only in regions of very high excitation, e.g., during flares or above ...

  7. Broadband Radio Spectral Observations of Solar Eclipse on 2008-08-01 and Implications on the Quiet Sun Atmospheric Model

    CERN Document Server

    Tan, Baolin; Zhang, Yin; Tan, Chengmin; Huang, Jing; Liu, Yuying; Fu, Qijun; Chen, ZhiJun; Liu, Fei; Chen, Linjie; Ji, Guoshu; 10.1007/s11433-009-0230-y

    2009-01-01

    Based on the joint-observations of the radio broadband spectral emissions of solar eclipse on August 1, 2008 at Jiuquan (total eclipse) and Huairou (partial eclipse) at the frequencies of 2.00 -- 5.60 GHz (Jiuquan), 2.60 -- 3.80 GHZ (Chinese solar broadband radiospectrometer, SBRS/Huairou), and 5.20 -- 7.60 GHz (SBRS/Huairou), the authors assemble a successive series of broadband spectrum with a frequency of 2.60 -- 7.60 GHz to observe the solar eclipse synchronously. This is the first attempt to analyze the solar eclipse radio emission under the two telescopes located at different places with broadband frequencies in the periods of total and partial eclipse. With these analyses, the authors made a new semiempirical model of the coronal plasma density of the quiet Sun and made a comparison with the classic models.

  8. Effects of solar eclipse on the electrodynamical processes of the equatorial ionosphere: a case study during 11 August 1999 dusk time total solar eclipse over India

    Directory of Open Access Journals (Sweden)

    R. Sridharan

    Full Text Available The effects on the electrodynamics of the equatorial E- and F-regions of the ionosphere, due to the occurrence of the solar eclipse during sunset hours on 11 August 1999, were investigated in a unique observational campaign involving ground based ionosondes, VHF and HF radars from the equatorial location of Trivandrum (8.5° N; 77° E; dip lat. 0.5° N, India. The study revealed the nature of changes brought about by the eclipse in the evening time E- and F-regions in terms of (i the sudden intensification of a weak blanketing ES-layer and the associated large enhancement of the VHF backscattered returns, (ii significant increase in h' F immediately following the eclipse and (iii distinctly different spatial and temporal structures in the spread-F irregularity drift velocities as observed by the HF radar. The significantly large enhancement of the backscattered returns from the E-region coincident with the onset of the eclipse is attributed to the generation of steep electron density gradients associated with the blanketing ES , possibly triggered by the eclipse phenomena. The increase in F-region base height immediately after the eclipse is explained as due to the reduction in the conductivity of the conjugate E-region in the path of totality connected to the F-region over the equator along the magnetic field lines, and this, with the peculiar local and regional conditions, seems to have reduced the E-region loading of the F-region dynamo, resulting in a larger post sunset F-region height (h' F rise. These aspects of E-and F-region behaviour on the eclipse day are discussed in relation to those observed on the control day.

    Key words. Ionosphere (electric fields and currents; equatorial ionosphere; ionospheric irregularities

  9. The determination of area and time comparison of the partial solar eclipse at space science center, LAPAN

    Science.gov (United States)

    Filawati, S.; Gammamerdianti; Hidayat, E. E.; Suryana, Y.; Kesumaningrum, R.

    2016-11-01

    The observation of the partial solar eclipse in Bandung on March, 9th 2016 was done to measure the surface coverage area and to compare to NASA calculation. We have calculated solar disk coverage area based on image data at the maximum contact until final contact of the eclipse. We obtained that maximum eclipse was at 7:21 a.m. (UT+7) with 84.81% area of solar disk covered by Moon and the end of eclipse was at 8:31 a.m. (UT+7).

  10. Submillimeter solar limb profiles determined from observations of the total solar eclipse of 1988 March 18

    Science.gov (United States)

    Roellig, T. L.; Becklin, E. E.; Jefferies, J. T.; Kopp, G. A.; Lindsey, C. A.; Orrall, F. Q.; Werner, M. W.

    1991-01-01

    Observations were made of the extreme solar limb in six far-infrared wavelength bands ranging from 30 to 670 micron using the Kuiper Airborne Observatory during the total eclipse of the sun on 1988 March 18. By observations of the occultation of the solar limb by the moon, it was possible to obtain a spatial resolution of 0.5 arcsec normal to the limb. The solar limb was found to be extended with respect to the visible limb at all of these wavelengths, with the extension increasing with wavelength. Limb brightening was observed to increase slightly with increasing wavelength, and no sign of a sharp emission spike at the extreme limb was found at any of these wavelengths. The observations can be well fitted by a chromospheric model incorporating cool dense spicules in the lower chromosphere.

  11. Prediction of the Solar Corona for the 2017 August 21 Total Solar Eclipse

    Science.gov (United States)

    Mikic, Zoran; Downs, Cooper; Linker, Jon A.; Caplan, Ronald M.; Lionello, Roberto; Torok, Tibor; Titov, Viacheslav; Riley, Pete; Mackay, Duncan; Upton, Lisa

    2017-08-01

    It has become our tradition to predict the structure of the corona prior to eclipses, using a magnetohydrodynamic (MHD) model based on measurements of photospheric magnetic fields on the Sun. We plan to continue this tradition for the August 21, 2017 total solar eclipse that will sweep across the United States. We will predict the structure of the corona using SDO/HMI photospheric magnetic field data, including images of polarization brightness, magnetic field line traces, and images of simulated emission in EUV and X-rays. These images can be compared directly with observations of the total eclipse, as well as observations from SDO/AIA, Hinode/XRT, and STEREO/EUVI. This year we will attempt to energize the magnetic field within filament channels for a more realistic prediction, by constructing flux ropes at the locations where filament channels are observed. The handedness of the flux ropes will be deduced from a magnetofrictional model driven by the evolving photospheric field produced by the Advective Flux Transport model.Research supported by NASA's Heliophysics Supporting Research and Living With a Star Programs.

  12. Possible radiative decays of solar neutrinos. Expectations from the total solar eclipse - 11th August 1999

    CERN Document Server

    Tanasa, A

    2001-01-01

    The paper treats the possibility of radiative decays of the oscillation product of the electron neutrinos coming from the Sun; to eliminate the background of photons collected with the telescope, the totality phase of the Total Solar Eclipse from August, 1999 in Romania will be used. To minimize this background in the NOTTE experiment (Neutrino Oscillation with Telescope during the Total Eclipse) one telescope will be mounted aboard a MIG29 plain flying in the totality band at high altitude. A theoretical calculation of the distribution of the distance from the center of the telescope for the decay photons is presented. Similar experiments could be placed aboard satellites having the advantage that the Earth occults the Sun every day while the detection time would be much longer than a typical eclipse duration. A positive result of such an experiment would be relevant not only for neutrino physics but also for astroparticle physics, dark matter searches and cosmology. Even negative results would lead to impro...

  13. Stellar background observation during Total Solar Eclipse March 9th 2016

    Science.gov (United States)

    Mumtahana, Farahhati; Timur Jaelani, Anton; Muhamad, Johan; Sutastio, Heri

    2016-11-01

    We report observation and an early analysis of stellar background from total solar eclipse in Ternate, Indonesia. The eclipse phenomena which occurred on March, 9th 2016 was observed with certain portable instruments in order to obtain the stars behind the Sun in particular field of view and resolution. From our observation site in Ternate city, solar eclipse occurred in the late morning when the weather was unfortunately cloudy. However, during the darkness of totality, we obtained several point source objects between the gaps of the moving clouds and we suspected them as very faint stars due to their appearance in several frames. Those so called stars have been identified and measured with respect to their positions toward the center of the Sun. The main purpose of this research is to revisit strong lensing calculation of the Sun during total solar eclipse by measuring the deflection angle of the background stars as it had been calculated by Einstein and proved by Eddington at a total solar eclipse in 1919. To accomplish this aim, we need to conduct another observation to measure position of the same stars in the next period when those stars appear in the night sky.

  14. Perception of Solar Eclipses Captured by Art Explains How Imaging Misrepresented the Source of the Solar Wind.

    Science.gov (United States)

    Woo, Richard

    2015-12-01

    The visible corona revealed by the natural phenomenon of solar eclipses has been studied for 150 years. A turning point has been the discovery that the true spatial distribution of coronal brightness can neither be seen nor imaged on account of its unprecedented dynamic range. Howard Russell Butler (1856-1934), the painter of solar eclipses in the early 20th century, possessed the extraordinary skill of painting from memory what he saw for only a brief time. His remarkable but forgotten eclipse paintings are, therefore, ideal for capturing and representing best the perceptual experience of the visible corona. Explained here is how by bridging the eras of visual (late 19th century) and imaging investigations (since the latter half of the 20th century), Butler's paintings reveal why white-light images misled researching and understanding the Sun's atmosphere, the solar wind. The closure in understanding solar eclipses through the convergence of perception, art, imaging, science and the history of science promises to enrich the experience of viewing and photographing the first solar eclipse of the 21st century in the United States on 21st August 2017.

  15. Perception of Solar Eclipses Captured by Art Explains How Imaging Misrepresented the Source of the Solar Wind

    Directory of Open Access Journals (Sweden)

    Richard Woo

    2015-11-01

    Full Text Available The visible corona revealed by the natural phenomenon of solar eclipses has been studied for 150 years. A turning point has been the discovery that the true spatial distribution of coronal brightness can neither be seen nor imaged on account of its unprecedented dynamic range. Howard Russell Butler (1856–1934, the painter of solar eclipses in the early 20th century, possessed the extraordinary skill of painting from memory what he saw for only a brief time. His remarkable but forgotten eclipse paintings are, therefore, ideal for capturing and representing best the perceptual experience of the visible corona. Explained here is how by bridging the eras of visual (late 19th century and imaging investigations (since the latter half of the 20th century, Butler’s paintings reveal why white-light images misled researching and understanding the Sun’s atmosphere, the solar wind. The closure in understanding solar eclipses through the convergence of perception, art, imaging, science and the history of science promises to enrich the experience of viewing and photographing the first solar eclipse of the 21st century in the United States on 21st August 2017.

  16. The 2016-2100 total solar eclipse prediction by using Meeus Algorithm implemented on MATLAB

    Science.gov (United States)

    Melati, A.; Hodijah, S.

    2016-11-01

    The phenomenon of solar and lunar eclipses can be predicted where and when it will happen. The Total Solar Eclipse (TSE) phenomenon on March 09th, 2016 became revival astronomy science in Indonesia and provided public astronomy education. This research aims to predict the total solar eclipse phenomenon from 2016 until 2100. We Used Besselian calculations and Meeus algorithms implemented in MATLAB R2012b software. This methods combine with VSOP087 and ELP2000-82 algorithm. As an example of simulation, TSE prediction on April 20th, 2042 has 0.2 seconds distinction of duration compared with NASA prediction. For the whole data TSE from year of 2016 until 2100 we found 0.04-0.21 seconds differences compared with NASA prediction.

  17. The Interaction of Cultural Rituals and the Concepts of Science in Student Learning: A Case Study on Solar Eclipse.

    Science.gov (United States)

    Mohapatra, J. K.

    1991-01-01

    Investigates the relevance and concomitant impact of sociocultural experiences upon the scientific literacy of 87 students, aged 13 to 16, concerning their comprehension and assimilation of scientific data involving solar eclipses. Results indicate that the students' nonscientific conceptions about solar eclipses, generated through sociocultural…

  18. The Interaction of Cultural Rituals and the Concepts of Science in Student Learning: A Case Study on Solar Eclipse.

    Science.gov (United States)

    Mohapatra, J. K.

    1991-01-01

    Investigates the relevance and concomitant impact of sociocultural experiences upon the scientific literacy of 87 students, aged 13 to 16, concerning their comprehension and assimilation of scientific data involving solar eclipses. Results indicate that the students' nonscientific conceptions about solar eclipses, generated through sociocultural…

  19. Assessing the impact of a solar eclipse on weather and photovoltaic production

    Directory of Open Access Journals (Sweden)

    Carmen Köhler

    2016-02-01

    Full Text Available With the strong expansion of the installed renewable energy over the last years, the relevance of weather forecasts for operating the German power system has considerably increased. In that context, rare but important events like the solar eclipse on the morning of 20 March 2015 pose an additional challenge when operating the power system, as it affects the photovoltaic (PV power production by inducing strong gradients in the feed-in. In order to maintain grid stability, the uncertainties associated with the eclipse have been estimated in advance for planning necessary precautions. Especially the maximum gradients in PV-power were of importance for the provision of balancing energy. Numerical weather prediction (NWP is very suited for this assessment, as it allows to consider the complex mechanisms occurring in the atmosphere. Thus the impact of the eclipse on meteorological parameters which affect the PV-power generation were evaluated. Sensitivity studies with NWP models have been conducted in order to assess the reduction in short wave radiation and temperature during the total solar eclipse months before the actual event. For this purpose, model simulations with the non-hydrostatic COSMO models from the German Weather Service (DWD have been performed over Germany and Europe. As the weather situation and especially the cloud cover during the eclipse could not be known in advance, a realistic worst case (clear sky conditions and a best case (overcast conditions scenario were simulated over Germany. Thereof the PV-power production has been estimated and analyzed for the different scenarios. The NWP model data from the sensitivity studies are openly distributed (doi:10.1594/PANGAEA.839163. As near real-time NWP simulations considering the solar eclipse were conducted a few days prior to the event, they are herein validated with measurements. Furthermore, the actual PV-power production and actions taken by the TSOs during the solar eclipse are

  20. Effect of March 9, 2016 Total Solar Eclipse on geomagnetic field variation

    Science.gov (United States)

    Ruhimat, Mamat; Winarko, Anton; Nuraeni, Fitri; Bangkit, Harry; Aris, M. Andi; Suwardi; Sulimin

    2016-11-01

    During solar eclipse, solar radiation to the Earth is blocked by the Moon. Thus, the ionization process in the ionosphere is disrupted, as well as the variation of geomagnetic field. The disturbance of geomagnetic field is caused by electric current in the E layer of the ionosphere. At low latitude, the current which is dominant in quiet day is the Sq currents. The blocking of solar radiation cause decrement in electron density in the blocked region. The aim of the research is to find the effect of total solar eclipse to the geomagnetic field. The measurement of the geomagnetic field variation during total solar eclipse on March 9, 2016 was carried out at the Meteorological station of BMKG in Ternate (0° 49' 45.20 "N; 127° 22' 54.00" E). By eliminating the geomagnetic disturbance that occurred in a daily geomagnetic field variation, the pattern of quiet day which is usually in a shape of smooth curve became affected. During the total solar eclipse on March 9, 2016 from 00:30 until 02:00 UT, we found that the geomagnetic field variation of the quiet day decreased by -5 nT.

  1. Australian solar eclipse expeditions: the voyage to Cape York in 1871

    Science.gov (United States)

    Lomb, Nick

    2016-04-01

    Techniques such as photography and spectroscopy only became available to study solar eclipses in the 1860s. The first subsequent total eclipse of the Sun to be visible from Australia was one in December 1871 that was visible from far north Queensland. Initiated by the Royal Society of Victoria, astronomers in Melbourne and Sydney cooperated to organise the Australian Eclipse Expedition aboard the steamship Governor Blackall to a suitable observing location. Though on the day of the eclipse clouds prevented viewing, this was an important expedition that was complex to organise and involved dealings with colonial Governments and with relatively large sums of money that Australian scientists had not previously experienced. With a newspaper reporter as part of the expedition along with two photographers the expedition was well recorded and provides a clear insight into the activities of late nineteenth century astronomers and other scientists.

  2. Response of Cassava canopy to mid-day pseudo sunrise induced by solar eclipse.

    Science.gov (United States)

    Latha, R; Murthy, B S

    2013-07-01

    Variations in CO(2) concentration over a cassava canopy were measured during a solar eclipse at Thiruvananthapuram, India. The analysis presented attempts to differentiate between the eclipse effect and the possible effect of thick clouds, taking CO(2) as a proxy for photosynthesis. CO(2) and water vapor were measured at a rate of 10 Hz, and radiation at 1 Hz, together with other meteorological parameters. A rapid reduction in CO(2) observed post-peak eclipse, due apparently to intense photosynthesis, appears similar to what happens at daybreak/post-sunrise. The increase in CO(2) (4 ppm) during peak eclipse, with radiation levels falling below the photosynthesis cut-off for cassava, indicates domination of respiration due to the light-limiting conditions.

  3. Response of Cassava canopy to mid-day pseudo sunrise induced by solar eclipse

    Science.gov (United States)

    Latha, R.; Murthy, B. S.

    2013-07-01

    Variations in CO2 concentration over a cassava canopy were measured during a solar eclipse at Thiruvananthapuram, India. The analysis presented attempts to differentiate between the eclipse effect and the possible effect of thick clouds, taking CO2 as a proxy for photosynthesis. CO2 and water vapor were measured at a rate of 10 Hz, and radiation at 1 Hz, together with other meteorological parameters. A rapid reduction in CO2 observed post-peak eclipse, due apparently to intense photosynthesis, appears similar to what happens at daybreak/post-sunrise. The increase in CO2 (4 ppm) during peak eclipse, with radiation levels falling below the photosynthesis cut-off for cassava, indicates domination of respiration due to the light-limiting conditions.

  4. Ionospheric response over Europe during the solar eclipse of March 20, 2015

    Science.gov (United States)

    Hoque, Mohammed Mainul; Wenzel, Daniela; Jakowski, Norbert; Gerzen, Tatjana; Berdermann, Jens; Wilken, Volker; Kriegel, Martin; Sato, Hiroatsu; Borries, Claudia; Minkwitz, David

    2016-10-01

    The solar eclipse on March 20, 2015 was a fascinating event for people in Northern Europe. From a scientific point of view, the solar eclipse can be considered as an in situ experiment on the Earth's upper atmosphere with a well-defined switching off and on of solar irradiation. Due to the strong changes in solar radiation during the eclipse, dynamic processes were initiated in the atmosphere and ionosphere causing a measurable impact, for example, on temperature and ionization. We analyzed the behavior of total ionospheric ionization over Europe by reconstructing total electron content (TEC) maps and differential TEC maps. Investigating the large depletion zone around the shadow spot, we found a TEC reduction of up to 6 TEC units, i.e., the total plasma depletion reached up to about 50%. However, the March 20, 2015 eclipse occurred during the recovery phase of a strong geomagnetic storm and the ionosphere was still perturbed and depleted. Therefore, the unusual high depletion is due to the negative bias of up to 20% already observed over Northern Europe before the eclipse occurred. After removing the negative storm effect, the eclipse-induced depletion amounts to about 30%, which is in agreement with previous observations. During the solar eclipse, ionospheric plasma redistribution processes significantly affected the shape of the electron density profile, which is seen in the equivalent slab thickness derived by combining vertical incidence sounding (VS) and TEC measurements. We found enhanced slab thickness values revealing, on the one hand, an increased width of the ionosphere around the maximum phase and, on the other, evidence for delayed depletion of the topside ionosphere. Additionally, we investigated very low frequency (VLF) signal strength measurements and found immediate amplitude changes due to ionization loss at the lower ionosphere during the eclipse time. We found that the magnitude of TEC depletion is linearly dependent on the Sun's obscuration

  5. Ionospheric response over Europe during the solar eclipse of March 20, 2015

    Directory of Open Access Journals (Sweden)

    Hoque Mohammed Mainul

    2016-01-01

    Full Text Available The solar eclipse on March 20, 2015 was a fascinating event for people in Northern Europe. From a scientific point of view, the solar eclipse can be considered as an in situ experiment on the Earth’s upper atmosphere with a well-defined switching off and on of solar irradiation. Due to the strong changes in solar radiation during the eclipse, dynamic processes were initiated in the atmosphere and ionosphere causing a measurable impact, for example, on temperature and ionization. We analyzed the behavior of total ionospheric ionization over Europe by reconstructing total electron content (TEC maps and differential TEC maps. Investigating the large depletion zone around the shadow spot, we found a TEC reduction of up to 6 TEC units, i.e., the total plasma depletion reached up to about 50%. However, the March 20, 2015 eclipse occurred during the recovery phase of a strong geomagnetic storm and the ionosphere was still perturbed and depleted. Therefore, the unusual high depletion is due to the negative bias of up to 20% already observed over Northern Europe before the eclipse occurred. After removing the negative storm effect, the eclipse-induced depletion amounts to about 30%, which is in agreement with previous observations. During the solar eclipse, ionospheric plasma redistribution processes significantly affected the shape of the electron density profile, which is seen in the equivalent slab thickness derived by combining vertical incidence sounding (VS and TEC measurements. We found enhanced slab thickness values revealing, on the one hand, an increased width of the ionosphere around the maximum phase and, on the other, evidence for delayed depletion of the topside ionosphere. Additionally, we investigated very low frequency (VLF signal strength measurements and found immediate amplitude changes due to ionization loss at the lower ionosphere during the eclipse time. We found that the magnitude of TEC depletion is linearly dependent on the

  6. The equatorial ionospheric response over Tirunelveli to the 15 January 2010 annular solar eclipse: observations

    Directory of Open Access Journals (Sweden)

    C. K. Nayak

    2012-09-01

    Full Text Available In this paper we present a case study of the annular solar eclipse effects on the ionization of E and F regions of equatorial ionosphere over Tirunelveli [77.8° E, 8.7° N, dip 0.4° N] by means of digital ionosonde on 15 January 2010. The maximum obscuration of the eclipse at this station was 84% and it occurred in the afternoon. The E and F1 layers of the ionosphere showed very clear decrease in their electron concentrations, whereas the F2 layer did not show appreciable changes. A reduction of 30% was observed in the foF1 during the maximum phase of the eclipse. During the beginning phase of the eclipse, an enhancement of 0.97 MHz was observed in the foF2 as compared to that of the control days. But the foF2 decreased gradually as the eclipse progressed and a decrease of 0.59 MHz was observed towards the end phase of the eclipse. Observed variations in the h'F2 and hmF2 showed lower values than the control days, although hmF2 was found to increase a bit during the eclipse. Observed variability in the E, F1 and F2 layer ionospheric parameters on the eclipse day and their departure from the control days are discussed as the combined effect of annular eclipse and presence of counter equatorial electrojet (CEEJ.

  7. Changes in Latitude, Changes in Attitude: U.S. Naval Observatory Observations of Solar Eclipses 1869 to the Present

    Science.gov (United States)

    Chizek Frouard, Malynda R.; Towne, Linda; Kaplan, George H.

    2017-01-01

    In anticipation of the 2017 August 21 total solar eclipse over the continental United States, the history of U.S. Naval Observatory eclipse observations illustrates the changes in science, technology, and policy over the past 148 years.USNO eclipse observations began in 1869, when staff traveled to Des Moines, Iowa and the Bering Strait to look for intra-mercurial planets and to observe the solar corona. During the golden age of eclipse expeditions, the USNO officially participated in a dozen expeditions between 1869 and 1929. Seven of these expeditions were to US locations: 1869 in Iowa; 1878 in Colorado, Wyoming, and Texas; 1880 in California; 1900 in Georgia and North Carolina; 1918 in Oregon; 1923 in California; and 1925 in New York. A total solar eclipse has not traced a path across the width of the continental US since 1918 although several eclipses have passed over parts of the US since then.A few official expeditions occurred later in the 20th century to measure the solar diameter, including a total eclipse in the northwest US in 1979 and an annular eclipse across the southeast in 1984. However, observations began transitioning to mostly personal adventures as individual astronomers arranged unofficial trips.Historians can use the USNO Multi-year Interactive Computer Almanac (MICA) to compute local circumstances for solar eclipses world-wide starting with the annual eclipse of 1800 April 24, which was visible from Alaska. Those looking to make history in 2017 may consult the USNO 2017 August 21 Solar Eclipse Resource page (http://aa.usno.navy.mil/data/docs/Eclipse2017.php).

  8. Effects of solar eclipse on the ionosphere observed by the Doppler sounding

    Science.gov (United States)

    Sindelarova, Tereza; Mosna, Zbysek; Chum, Jaroslav

    2017-04-01

    The Doppler sounding of the ionosphere is based on measurements of the frequency shift between the transmitted and received radio wave of a stable known frequency. The frequency shift is related to changes of the phase path of the radio wave and can be influenced by the vertical motion of the reflecting layer due to gravity waves, by compression and rarefaction of gas at a fixed height owing to infrasound waves or by changes of electron density due to changes of ionization rate e.g. during the solar eclipse or solar flares. We studied effects of total solar eclipses on 20 March 2015 in the Czech Republic and on 9 March 2016 on Taiwan. In both events, the Doppler sounding was located in the area of partial eclipse. Distinct disturbance was observed around the time of the maximum eclipse. We assume that it is related to processes at the site of measurements rather than to waves propagating from the region of total eclipse.

  9. Preliminary results of the solar corona spectroscopic observation of 9th March 2016 Total Solar Eclipse

    Science.gov (United States)

    Sungging Mumpuni, Emanuel; Zamzam Nurzaman, Muhamad; Suryana, Nana

    2016-11-01

    Spectroscopy observation of solar corona has been carried out from 9th March 2016 Total Solar Eclipse expedition in Maba, East Halmahera. Due to limitation by the weather condition during the observation, the obtained data were not favorable. Because of the low signal to noise ratio, the wavelength calibration was not straightforward. To obtain the optimum results, steps for data reduction were performed as the following: selecting the finest data, extracting the 1D spectrum from 2D spectrum, and calibrating spectrum wavelength (including careful interpolation). In this preliminary result, we discuss the instrumentation, the data under investigation, the extraction process of spectrum, and the polynomial interpolation that has been used for extracting information from our data.

  10. The Temperature of the Corona as Derived from Total Solar Eclipse Observations

    Science.gov (United States)

    Habbal, Shadia R.; Morgan, Huw; Druckmuller, Miloslav; Ding, Adalbert

    2016-05-01

    Multiwavelength imaging observations in a suite of coronal forbidden lines of the corona during total solar eclipses enables the empirical inference of the spatial distribution of temperature in the solar corona up to a few solar radii above the limb. The temperature sensitivity of coronal emission lines is such that temperature differences of 105 K can be detected in the images. Using high resolution multiwavelength and white light eclipse images acquired since 2006, covering almost a solar cycle, we show evidence for (1) how the distribution of the temperature in the corona is bimodal, with closed coronal structures dominated by 2 106 K plasma, while structures streaming away from the Sun are dominated by 106 K emission, (2) prominences are invariably enshrouded by the hottest material in the corona, and (3) that the dominance of one temperature versus the other is solar-cycle dependent.

  11. Effect of the total solar eclipse of March 20, 2015, on VLF/LF propagation

    Science.gov (United States)

    Solovieva, M. S.; Rozhnoi, A. A.; Fedun, V.; Schwingenschuh, K.

    2016-05-01

    The analyzed amplitude and phase variations in electromagnetic VLF and LF signals at 20-45 kHz, received in Moscow, Graz (Austria), and Sheffield (UK) during the total solar eclipse of March 20, 2015, are considered. The 22 analyzed paths have lengths of 200—6100 km, are differently oriented, and cross 40-100% occultation regions. Fifteen paths crossed the region where the occultation varied from 40 to 90%. Solar eclipse effects were found only on one of these paths in the signal phase (-50°). Four long paths crossed the 90-100% occultation region, and signal amplitude and phase anomalies were detected for all four paths. Negative phase anomalies varied from-75° to-90°, and the amplitude anomalies were both positive and negative and were not larger than 5 dB. It was shown that the effective height of the ionosphere varied from 6.5 to 11 km during the eclipse.

  12. A Mathematical Model of the Great Solar Eclipse of 1991.

    Science.gov (United States)

    Lamb, John Jr.

    1991-01-01

    An activity that shows how mathematics can be used to model events in the real world is described. A way to calculate the area of the sun covered by the moon during a partial eclipse is presented. A computer program that will determine the coverage percentage is also included. (KR)

  13. A Mathematical Model of the Great Solar Eclipse of 1991.

    Science.gov (United States)

    Lamb, John Jr.

    1991-01-01

    An activity that shows how mathematics can be used to model events in the real world is described. A way to calculate the area of the sun covered by the moon during a partial eclipse is presented. A computer program that will determine the coverage percentage is also included. (KR)

  14. Impacts of the total solar eclipse of 9 March 2016 on meteorological parameters in Ternate

    Science.gov (United States)

    Satyaningsih, R.; Heriyanto, E.; Kadarsah; Nuraini, TA; Rizal, J.; Sopaheluwakan, A.; Aldrian, E.

    2016-11-01

    The total solar eclipse on 9th March 2016 has given a unique opportunity to assess impacts of the eclipse on various meteorological parameters in Ternate. A weather transmitter, a net radiometer, and a heat flux plate for measuring soil heat flux in bare soil were deployed during this special observation in Madaha, Ternate (0°51'17.5" N, 127°20'56.8" E). The measured meteorological parameters presented here are net radiation, air temperature, relative humidity, and soil heat flux. The results show that those parameters are significantly affected by the eclipse. The percentage of the observed decrease of net radiation during the eclipse was proportional to the obscuration percentage. The air temperature measured at 1.5 m declined around 1.9 °C with approximately 11 minutes lag between the mid-eclipse and minimum temperature during eclipse. Influences from the surrounding environment in the measurement site minimize the temperature response. As a consequence of temperature decrease, relative humidity increased. A drop in soil heat flux was also detected but its response was slower.

  15. Imaging and spectroscopic observations of the 9 March 2016 Total Solar Eclipse in Palangkaraya

    Science.gov (United States)

    Kholish, Abdul Majid Al; Jihad, Imanul; Taufik Andika, Irham; Puspitaningrum, Evaria; Ainy, Fathin Q.; Ramadhan, Sahlan; Ikbal Arifyanto, M.; Malasan, Hakim L.

    2016-11-01

    The March 9th 2016 total solar eclipse observation was carried out at Universitas Palangkaraya, Central Kalimantan. Time-resolved imaging of the Sun has been conducted before, after, and during totality of eclipse while optical spectroscopic observation has been carried out only at the totality. The imaging observation in white light was done to take high resolution images of solar corona. The images were taken with a DSLR camera that is attached to a refractor telescope (d=66 mm, f/5.9). Despite cloudy weather during the eclipse moments, we managed to obtain the images with lower signal-to-noise ratio, including identifiable diamond ring, prominence and coronal structure. The images were processed using standard reduction procedure to increase the signal-to-noise ratio and to enhance the corona. Then, the coronal structure is determined and compared with ultraviolet data from SOHO to analyze the correlation between visual and ultraviolet corona. The spectroscopic observation was conducted using a slit-less spectrograph and a DSLR camera to obtain solar flash spectra. The flash spectra taken during the eclipse show emissions of H 4861 Å, He I 5876 Å, and H 6563 Å. The Fe XIV 5303 Å and Fe X 6374 Å lines are hardly detected due to low signal-to-noise ratio. Spectral reduction and analysis are conducted to derive the emission lines intensity relative to continuum intensity. We use the measured parameters to determine the temperature of solar chromosphere.

  16. Solar eclipse effects of 22 July 2009 on Sporadic-E

    Directory of Open Access Journals (Sweden)

    G. Chen

    2010-02-01

    Full Text Available The total solar eclipse of 22 July 2009, was visible from some regions of China and the intense sporadic-E (Es that broke out during the solar eclipse period over the eastern China provided a unique chance to study solar eclipse effects on the Es-layer. The ground based high-frequency (HF vertical-incidence and oblique-incidence backscatter radio systems in Wuhan and an HF oblique receivers located in Suzhou were operated to detect the Es-layer. The vertical, oblique and backscatter ionograms of 22 and 23 July were recorded, processed and analyzed. The analyzing results show that the critical frequency of Es, the hop number and power of the rays transmitted from Wuhan to Suzhou as well as the Doppler frequency shift of the one-hop oblique-incidence waves reflected by the Es-layer all increased during the solar eclipse period. These variations are displayed in the paper and explained to be induced by the wind-field, which is produced by the powerful meridional air flows from the sunshine region to the moon's shadow.

  17. The sky brightness measurement during the 2016 solar eclipse in Ternate

    Science.gov (United States)

    Pramudya, Yudhiakto; Arkanuddin, Muchlas

    2016-11-01

    Obscuration of the Sun by the Moon during total solar eclipse generates the changing of the sky brightness. Sky Quality Meter (SQM) was employed to measure the sky brightness during the 2016 total solar eclipse. The sky was still bright at the first contact time. It is shown by the SQM value of zero. Approaching the second contact time, the SQM value is rising up started at the value of 5.92 mpsas. The curvature profile of the SQM measurementvalue is similar to the curvature profile of the SQM measurement at the dawn and dusk. However, the flatness part of the curvature is much shorter than night time value of SQM. The maximum of SQM measurement value is lower than the SQM measurement value during the night in Ternate. It is 12.47 mpsas and happened at the maximum phase of the eclipse. It was confirmed by the fact that at the time of totality, the sky close to the horizon was still bright. There is a discrepancy between the predicted and actual second and third contact and maximum eclipse time. By assigning the maximum of SQM measurement value as the reference value of maximum eclipse time, the actual second and third time can be calculated. The shape of curvature between the actual second and third contact time is symmetry.

  18. Ionospheric Effects of a Solar Eclipse of March 20, 2015 on Oblique Sounding Paths in the Eurasian Longitudinal Sector

    Science.gov (United States)

    Uryadov, V. P.; Kolchev, A. A.; Vybornov, F. I.; Shumaev, V. V.; Egoshin, A. I.; Chernov, A. G.

    2016-11-01

    The results of measuring HF signals on oblique chirp sounding paths in the Eurasian region during a solar eclipse of March 20, 2015 and the neighboring days are presented. The solar eclipse took place against the background of a strong magnetic storm. It was established that during the solar eclipse on oblique sounding paths of different length and orientation the decrease in the maximum observable frequency for the F mode (MOF-F) and the lowest observable frequency for the F mode (LOF-F) was 8-14% and 22-33%, respectively. During the eclipse, the signal amplitude increased by 3-5 dB. On the Lovozero—Nizhny Novgorod path in the maximum phase of the solar eclipse, the electron density decrease in the ionospheric E and F2 layers at the midpoint of the path reached 37% and 22%, respectively. According to the MOF and LOF variation measurements for various modes, the group delay time of radio signals, and the results of spectral analysis, it was found that in the eclipse there were wave disturbances with a period of 25 to 50 min. However, quasi-periodic variations of MOF-F and LOF-F having a a period of 50 to 80 min but which started before the eclipse were detected on some paths. Probably, in these cases, the variations were a result of the superposition of disturbances from two sources, namely, the magnetic storm and the solar eclipse.

  19. Multi-site Observations of the March 2016 Total Solar Eclipse: Calibration of Images to Simulate Continuous Monitoring

    Science.gov (United States)

    Bosh, Robert; Penn, Matthew J.; McKay, Myles; Baer, Robert; Garrison, David; Gelderman, Richard; Hare, Honor; Isberner, Fred; Jensen, Logan; Kovac, Sarah; Mitchell, Adriana; Pierce, Michael; Thompson, Patricia; Ursache, Andrei; Varsik, John R.; Walter, Donald K.; Watson, Zachary; Young, David; Citizen Cate Team

    2017-01-01

    During the total solar eclipse of March 9, 2016, five teams of astronomers participating in the Citizen Continental America Telescopic Eclipse (CATE) experiment, traveled to different locations in Indonesia to observe the eclipse. Data was acquired to continuously monitor the progression of features in the inner solar corona: a region of the solar atmosphere where time evolution is not well understood. Image data from the eclipse consisted of sets of 7 exposure times 0.4, 1.3, 4, 13, 40, 130, and 400 milliseconds which are used to create a high dynamic range composite image. Eclipse data from these sites were then processed and calibrated using sets of dark and flat images. Further data processing included the compilation of exposures into high dynamic range images and were subsequently spatially filtered. Using these processing techniques, data from each site was aligned and compiled as frames in videos of the eclipse, each consisting of over 140 frames with the goal of being combined. Lessons learned from the data obtained in the observations of the 2016 total solar eclipse are being used to improve the procedure which will be used in the CATE experiment during the North American 2017 total solar eclipse.

  20. Coronal structure analysis based on the potential field source surface modeling and total solar eclipse observation

    Science.gov (United States)

    Muhamad, Johan; Mumtahana, Farahhati; Sutastio, Heri; Imaduddin, Irfan; Putri, Gerhana P.

    2016-11-01

    We constructed global coronal magnetic fields of the Sun during the Total Solar Eclipse (TSE) 9 March 2016 by using Potential Field Source Surface (PFSS) model. Synoptic photospheric magnetogram data from Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) was used as a boundary condition to extrapolate the coronal magnetic fields of the Sun. This extrapolated structure was analyzed by comparing the alignment of the fields from the model with coronal structure from the observation. We also used observational data of coronal structure during the total solar eclipse to know how well the model agree with the observation. As a result, we could identify several coronal streamers which were produced by the large closed loops in the lower regime of the corona. This result verified that the PFSS extrapolation can be used as a tool to model the inner corona with several constraints. We also discussed how the coronal structure can be used to deduce the phase of the solar cycle.

  1. The acoustic-gravity wave effects of the solar eclipse%日食声重波效应

    Institute of Scientific and Technical Information of China (English)

    何友文; 孙宏林

    2001-01-01

    By using the data of the rapid-run ionosonde the solar eclipseeffects were summarized at the Manzhouli、 Changchun and Beijing ionospheric observatory during the 9 March 1997 total solar eclipse. It must be pointed out that: (1) The Manzhouli ionospheric observatory was situated north of the position of the total solar eclipse path on 200 km above sea level, the Changchun and Beijing ionospheric observatory were south ; (2) The time for two successive observations was one minute for ten or twenty minutes around the middle of eclipse and five minute for the rest. It shows that: there are the traveling ionosphere disturbances (TID) caused by the acoustic gravity wave in the belt of solar eclipse during the solar eclipse. The TID was excited by the solar eclipse. The motional characteristics of the acoustic gravity wave offects of the solar eclipse were also discussed briefly.%介绍了1997年3月9日日食期间,首次利用地跨主食带区两侧的电离层台阵,食甚前后采用1min1次的同步加密观测的资料。观测证实:日食期间在主食带区日食确有可能诱发声重波所致的电离层行扰现象(TID)。并对其运动学特征作了粗浅的讨论。

  2. Organic and hybrid solar cells

    CERN Document Server

    Huang, Hui

    2014-01-01

    This book delivers a comprehensive evaluation of organic and hybrid solar cells and identifies their fundamental principles and numerous applications. Great attention is given to the charge transport mechanism, donor and acceptor materials, interfacial materials, alternative electrodes, device engineering and physics, and device stability. The authors provide an industrial perspective on the future of photovoltaic technologies.

  3. Towards stable silicon nanoarray hybrid solar cells.

    Science.gov (United States)

    He, W W; Wu, K J; Wang, K; Shi, T F; Wu, L; Li, S X; Teng, D Y; Ye, C H

    2014-01-16

    Silicon nanoarray hybrid solar cells benefit from the ease of fabrication and the cost-effectiveness of the hybrid structure, and represent a new research focus towards the utilization of solar energy. However, hybrid solar cells composed of both inorganic and organic components suffer from the notorious stability issue, which has to be tackled before the hybrid solar cells could become a viable alternative for harvesting solar energy. Here we show that Si nanoarray/PEDOT:PSS hybrid solar cells with improved stability can be fabricated via eliminating the water inclusion in the initial formation of the heterojunction between Si nanoarray and PEDOT:PSS. The Si nanoarray hybrid solar cells are stable against rapid degradation in the atmosphere environment for several months without encapsulation. This finding paves the way towards the real-world applications of Si nanoarray hybrid solar cells.

  4. Solar eclipse represented in the petroglyphs of Vigirima (Venezuela

    Directory of Open Access Journals (Sweden)

    Nelson Falcón

    2013-05-01

    Using archaeo-astronomic techniques some petroglyphs considered to contain astronomical content have been analysed and it was concluded that they corresponded to the total eclipse of the sun, which took place in 577 AC. Following that, the construction of a cultural model showing the possible significance of the petroglyphs as archetypal expressions of the socio-cultural structure of the ethnic groups who created them, was proposed.

  5. Multiple ESD Risk On Geostationary Solar Arrays At Eclipse Exit

    Science.gov (United States)

    Payan, D.; Balcon, N.; Paulmier, T.; Birassen, B.

    2011-10-01

    From charging process to ESD1, authors will explain that ESD risk on a spacecraft is a global problem where conductivity of different assemblies (including glue) is the main point. Improving general conductivity on a spacecraft, connecting metallic parts to the structure even those which are embedded in glue or dielectric and use of future meshed dielectric where the conductive meshing is dedicated to electrons bleeding, will be the next step to avoid ESD, even in risky configuration as eclipse exit.

  6. Ludendorff Coronal Flattening Index of the Total Solar Eclipse on March 9, 2016

    OpenAIRE

    Dani, Tiar; Priyatikanto, Rhorom; Rachman, Abdul

    2016-01-01

    Ludendorff coronal flattening index of the Total Solar Eclipse (TSE) on March 9, 2016, was calculated at various distances in solar radius. As a result, we obtained the coronal flattening index $\\left(\\epsilon =a+b\\right)$ at a distance of 2 solar radii is 0.16. The $24^{th}$ solar cycle phase based on the 2016 TSE event obtained -0.64 which showed the corona is pre-minimum type. Resulted coronal flattening index value gives a predicted maximum amplitude of the monthly sunspot number ($W_{max...

  7. The orientation of the sandhopper Talitrus saltator during a partial solar eclipse.

    Science.gov (United States)

    Ugolini, A; Castellini, C; Tiribilli, B

    2004-10-01

    To acquire more information about the identification and use of the sun and other celestial cues in the sea-land orientation of the sandhopper Talitrus saltator, we carried out releases in a confined environment during a partial solar eclipse and at sunset. The sandhoppers were unable to identify the sun (86% covered) during the eclipse nor to use other celestial compass factors of orientation. This was probably due to the low level of light intensity (close to the minimum level for orientation recorded at sunset) and to the variations in intensity and pattern of skylight polarization.

  8. Ludendorff Coronal Flattening Index of the Total Solar Eclipse on March 9, 2016

    CERN Document Server

    Dani, Tiar; Rachman, Abdul

    2016-01-01

    Ludendorff coronal flattening index of the Total Solar Eclipse (TSE) on March 9, 2016, was calculated at various distances in solar radius. As a result, we obtained the coronal flattening index $\\left(\\epsilon =a+b\\right)$ at a distance of 2 solar radii is 0.16. The $24^{th}$ solar cycle phase based on the 2016 TSE event obtained -0.64 which showed the corona is pre-minimum type. Resulted coronal flattening index value gives a predicted maximum amplitude of the monthly sunspot number ($W_{max}$) for the $25^{th}$ solar cycle to be $70\\pm65$. Therefore, the solar activity for $25^{th}$ solar cycle predicted to be lower than the current solar cycle, which has a maximum sunspot number value of 146 in February 2014

  9. Solar eclipse demonstrating the importance of photochemistry in new particle formation.

    Science.gov (United States)

    Jokinen, Tuija; Kontkanen, Jenni; Lehtipalo, Katrianne; Manninen, Hanna E; Aalto, Juho; Porcar-Castell, Albert; Garmash, Olga; Nieminen, Tuomo; Ehn, Mikael; Kangasluoma, Juha; Junninen, Heikki; Levula, Janne; Duplissy, Jonathan; Ahonen, Lauri R; Rantala, Pekka; Heikkinen, Liine; Yan, Chao; Sipilä, Mikko; Worsnop, Douglas R; Bäck, Jaana; Petäjä, Tuukka; Kerminen, Veli-Matti; Kulmala, Markku

    2017-04-04

    Solar eclipses provide unique possibilities to investigate atmospheric processes, such as new particle formation (NPF), important to the global aerosol load and radiative balance. The temporary absence of solar radiation gives particular insight into different oxidation and clustering processes leading to NPF. This is crucial because our mechanistic understanding on how NPF is related to photochemistry is still rather limited. During a partial solar eclipse over Finland in 2015, we found that this phenomenon had prominent effects on atmospheric on-going NPF. During the eclipse, the sources of aerosol precursor gases, such as sulphuric acid and nitrogen- containing highly oxidised organic compounds, decreased considerably, which was followed by a reduced formation of small clusters and nanoparticles and thus termination of NPF. After the eclipse, aerosol precursor molecule concentrations recovered and re-initiated NPF. Our results provide direct evidence on the key role of the photochemical production of sulphuric acid and highly oxidized organic compounds in maintaining atmospheric NPF. Our results also explain the rare occurrence of this phenomenon under dark conditions, as well as its seemingly weak connection with atmospheric ions.

  10. Eclipse intervals for satellites in circular orbit under the effects of Earth’s oblateness and solar radiation pressure

    Directory of Open Access Journals (Sweden)

    M.N. Ismail

    2015-06-01

    Full Text Available In this work, the circumstances of eclipse for a circular satellites’ orbit are studied. The time of passage of the ingress and egress points is calculated. Finally, the eclipse intervals of satellites’ orbit are calculated. An application was done taken into account the effects of solar radiation pressure and Earth’s oblateness on the orbital elements of circular orbit satellite.

  11. Submillimeter observations of solar limb-brightening in the total solar eclipse of 31 July 1981

    Science.gov (United States)

    Becklin, E. E.; Jefferies, J. T.; Lindsey, C.; Orrall, F.; Gatley, I.; Werner, M.

    1981-01-01

    Eight flights of the Kuiper Airborne Observatory (KAO) were devoted to solar observation. The successful observation of a total solar eclipse was accomplished. The observations were made simultaneously at 30, 50, 100, and 200 microns. The successful adaptation of the KAO for solar observations thus provided the most detailed data to date in this spectral band. The results from a preliminary analysis of the KAO data are summarized: (1) the 200 micron limb is extended about 3 arc sec above the 30 micron limb, indicating the prescence of cool dense material up to the altitudes of spicules; (2) strong radial darkening of the quiet sun intensity profile appeared at 200 microns, probably an indication that hot material in the low chromosphere is recessed into vertical magnetic flux tubes embedded in a cooler nonmagnetic substrate, which obscures the heated material approaching the limb; (3) active regions were observed to undergo a strong increase in contrast above the quiet sun background at wave lengths of 100 microns and longer; and (4) the moon was mapped for use as a photometric standard for determining the absolute intensity of the sun in all four wavelength bands.

  12. Coronal Mass Ejections Observed at the Total Solar Eclipse on 13 November 2012

    CERN Document Server

    Hanaoka, Yoichiro; Ohgoe, Osamu; Sakai, Yoshiaki; Shiota, Kazuo

    2013-01-01

    We carried out white-light observations of the total solar eclipse on 13 November 2012 at two sites, where the totality occurred 35 minutes apart. We caught an ongoing coronal mass ejection (CME) and a pre-CME loop structure just before the eruption in the height range between 1-2 R_sun. The source region of CMEs was revealed to be in this height range, where the material and the magnetic field of CMEs were located before the eruption. This height range includes the gap between the extreme ultraviolet observations of the low corona and the spaceborne white-light observations of the high corona, but the eclipse observation shows that this height range is essentially important to study the CME initiation. The eclipse observation is basically just a snapshot of CMEs, but it indicates that future continuous observations of CMEs within this height range are promising.

  13. Ionospheric response to the total solar eclipse of June 21, 2001

    CERN Document Server

    Afraimovich, E L

    2002-01-01

    We discuss the measurements of the main parameters of the ionospheric response to the total solar eclipse of June 21, 2001. This study is based on using the data from three stations of the global GPS network located in the area of the totality band in Africa. This period was characterized by a low level of geomagnetic disturbance (the Dst-index varied from -6 to 22 nT), which alleviated greatly the problem of detecting the ionospheric response to eclipse. An analysis revealed a clearly pronounced effect of a decrease (depression) of the total electron content (TEC) for all GPS stations. The delay between the smallest value of the TEC with respect to eclipse totality was 9-37 min. The depth and duration of the TEC depression were 0.5-0.9 TECU and 30-67 min, respectively. The results obtained in this study are in good agreement with earlier measurements and theoretical estimations.

  14. Educational and Public Outreach Strategies in Anticipation of the 2017 U.S. Total Solar Eclipse

    Science.gov (United States)

    Fulco, C.

    2015-12-01

    Those who have experienced a total solar eclipse will travel to every corner of the Earth to observe one, such is its spectacular nature. So it is fortunate indeed to have this remarkable event come to the U.S. in less than two years, with its path of totality from Oregon to South Carolina within a day's drive for most of the nation's population. The date of the 21 August 2017 "Great American Eclipse" is rapidly approaching, and with focus on science literacy in U.S. schools greater than ever, educational and public outreach (EPO) must begin in earnest to maximize the scientific and educational benefits from this rare event. As every location in the U.S. will observe at least a partial eclipse, having EPO strategies in place ensures that the greatest number of students and other observers throughout the country will: a) be aware of and prepared for this event, b) observe (and record) it safely and knowledgeably, and c) gain an increased awareness of the natural world. The need for teachers to promote scientific literacy through curriculum is critical for this event. Despite an increased presence of technology in the classroom, more rigorous educational learning standards and virtually instantaneous access to information, data show that science illiteracy in U.S. schools and in the general population is still widespread. In addition, much fear, ignorance and confusion continue to surround eclipses. Many school districts plan to keep students indoors during the eclipse, while the media can be expected to instruct the public to do the same, thus depriving would-be observers of an unforgettable and most likely a once-in-a-lifetime experience. It would be a tragedy on many levels if this eclipse were not viewed, recorded and remembered live and outdoors--not indoors watching on media--by as many persons as possible. Proper EPO strategies performed with ample lead time can ensure that the 2017 U.S. Total Solar Eclipse will be a success from coast-to-coast, and with it, a

  15. The ionospheric behavior in conjugate hemispheres during the 3 October 2005 solar eclipse

    Directory of Open Access Journals (Sweden)

    H. Le

    2009-01-01

    Full Text Available We investigate the ionospheric behavior in conjugate hemispheres during the 3 October 2005 solar eclipse, on the basis of observations of electron temperature (Te from the Defense Meteorological Satellites Program (DMSP spacecraft, F2 layer critical frequency (foF2 and F2 layer peak height (hmF2 at the Grahamstown ionosonde station, and total electron content (TEC from the Global Positioning System (GPS station SUTH. The observations show that when the eclipse occurred in the Northern Hemisphere, there was a decrease in Te, an increase in foF2 and TEC, and an uprising in hmF2 in its conjugate region compared with their reference values. We also simulated the ionosphere behavior during this eclipse using a mid- and low-latitude ionospheric model. The simulations agree well with the observations. Because of the eclipse effect, there are far fewer photoelectrons travelling along the magnetic field lines from the eclipse region to the conjugate region, resulting in reduced photoelectron heating in the conjugate hemisphere which causes a drop in electron temperature and subsequent disturbances in the region.

  16. Changes in Meteorological Parameters (i.e. UV and Solar Radiation, Air Temperature, Humidity and Wind Condition) during the Partial Solar Eclipse of 9 March 2016

    Science.gov (United States)

    Paramitha, B.; Zaen, R.; Nandiyanto, A. B. D.

    2017-03-01

    Solar eclipse is a spectacular phenomenon, which occurs when the position of the moon is between the sun and the earth. This phenomenon affects to the meteorological parameters, such as solar radiation, temperature, and humidity. The purpose of this study was to evaluate the impact of partial solar eclipse of 9 March 2016 to the change of several meteorological parameters. In the experimental procedure, we used automatic weather station (AWS) in one of building in Universitas Pendidikan Indonesia in Bandung. Bandung was selected because this place experienced partial (88.89%) solar eclipse on 9 March 2016. The result showed that compared to normal day, meteorological parameters changed during the solar eclipse, such as decreases in the UV and solar radiation, increases in relative humidity, and changes in air temperature and wind condition.

  17. Performance of the meteorological radiation model during the solar eclipse of 29 March 2006

    Directory of Open Access Journals (Sweden)

    B. E. Psiloglou

    2007-12-01

    Full Text Available Various solar broadband models have been developed in the last half of the 20th century. The driving demand has been the estimation of available solar energy at different locations on earth for various applications. The motivation for such developments, though, has been the ample lack of solar radiation measurements at global scale. Therefore, the main goal of such codes is to generate artificial solar radiation series or calculate the availability of solar energy at a place.

    One of the broadband models to be developed in the late 80's was the Meteorological Radiation Model (MRM. The main advantage of MRM over other similar models was its simplicity in acquiring and using the necessary input data, i.e. air temperature, relative humidity, barometric pressure and sunshine duration from any of the many meteorological stations.

    The present study describes briefly the various steps (versions of MRM and in greater detail the latest version 5. To show the flexibility and great performance of the MRM, a harsh test of the code under the (almost total solar eclipse conditions of 29 March 2006 over Athens was performed and comparison of its results with real measurements was made. From this hard comparison it is shown that the MRM can simulate solar radiation during a solar eclipse event as effectively as on a typical day. Because of the main interest in solar energy applications about the total radiation component, MRM focuses on that. For this component, the RMSE and MBE statistical estimators during this study were found to be 7.64% and −1.67% on 29 March as compared to the respective 5.30% and +2.04% for 28 March. This efficiency of MRM even during an eclipse makes the model promising for easy handling of typical situations with even better results.

  18. Performance of the meteorological radiation model during the solar eclipse of 29 March 2006

    Directory of Open Access Journals (Sweden)

    B. E. Psiloglou

    2007-08-01

    Full Text Available Various solar broadband models have been developed in the last half of the 20th century. The driving demand has been the estimation of available solar energy at different locations on earth for various applications. The motivation for such developments, though, has been the ample lack of solar radiation measurements at global scale. Therefore, the main goal of such codes was to generate artificial solar radiation series or calculate the availability of solar energy at a place.

    One of the broadband models to be developed in the late 80's was the Meteorological Radiation Model (MRM. The main advantage of MRM over other similar models was its simplicity in acquiring and using the necessary input data, i.e., air temperature, relative humidity, barometric pressure and sunshine duration from any of the many meteorological stations.

    The present study describes briefly the various steps (versions of MRM and in greater detail the latest version 5. To show the flexibility and great performance of the MRM, a harsh test of the code under the (almost total solar eclipse conditions of 29 March 2006 over Athens was performed and comparison of its results with real measurements was made. From this hard comparison it is shown that the MRM can simulate solar radiation during a solar eclipse event as effectively as on a typical day. The value of this comparison is further enhanced if it said that the sky was cloudy almost all the duration of the solar eclipse event.

  19. Plans to Observe the 2017 Total Solar Eclipse from near the Path Edges

    Science.gov (United States)

    Waring Dunham, David; Nugent, Richard; Guhl, Konrad; Bode, Hans-Joachim

    2015-08-01

    The August 21st, 2017 solar eclipse provides a good opportunity, to time the totality contacts, other Baily’s bead phenomena, and observe other dynamic edge phenomena, from locations near the edges of the path of totality. A good network of roads and generally favorable weather prospects means that more observers will likely be able to deploy more equipment than during most previous eclipses. The value of contact and Baily’s bead timings of total solar eclipses, for determining solar diameter and intensity variations, was described in an earlier presentation in Focus Meeting 13. This presentation will concentrate on how observations of different types that have been used during past eclipses can be made by different observers, to obtain better information about the accuracy of the different types of observations for determining the mean solar diameter, and the systematic differences between them. A problem has been that the few observers who have attempted recording Baily’s beads from path edge locations have wanted to use the latest technology, to try to record the observations better, rather than try to make the observations in the same ways that were used for many past eclipses. Several observers trying different techniques at the same location, and doing that at several locations at different places along the path, is needed. Past techniques that we would like to compare include direct visual observation (but keeping eye safety in mind); visual observation of telescopically projected images; direct filtered video telescopic observations; and recording the flash spectrum. There are several towns that straddle the path edges. The International Occultation Timing Association would like to mobilize people in those towns to observe the eclipse from many places, to say whether or not the eclipse happened, and if it did, time it. A suitable cell phone app could be designed to report observations, including the observer’s location, as was attempted for an

  20. Ionospheric measurements of relative coronal brightness during the total solar eclipses of 11 August, 1999 and 9 July, 1945

    Directory of Open Access Journals (Sweden)

    C. J. Davis

    Full Text Available Swept-frequency (1-10 MHz ionosonde measurements were made at Helston, Cornwall (50°06'N, 5°18'W during the total solar eclipse on August 11, 1999. Soundings were made every three minutes. We present a method for estimating the percentage of the ionising solar radiation which remains unobscured at any time during the eclipse by comparing the variation of the ionospheric E-layer with the behaviour of the layer during a control day. Application to the ionosonde date for 11 August, 1999, shows that the flux of solar ionising radiation fell to a minimum of 25±2% of the value before and after the eclipse. For comparison, the same technique was also applied to measurements made during the total solar eclipse of 9 July, 1945, at Sörmjöle (63°68'N, 20°20'E and yielded a corresponding minimum of 16±2%. Therefore the method can detect variations in the fraction of solar emissions that originate from the unobscured corona and chromosphere. We discuss the differences between these two eclipses in terms of the nature of the eclipse, short-term fluctuations, the sunspot cycle and the recently-discovered long-term change in the coronal magnetic field.

    Key words: Ionosphere (solar radiation and cosmic ray effects - Radio science (ionospheric physics - Solar physics, astrophysics, and astronomy (corona and transition region

  1. The influences of solar radiation changes on the meteorological variables during the total solar eclipse of 9th March 2016 in Central Bangka, Indonesia

    Science.gov (United States)

    Gandini, Ryantika; Ardi, NanangDwi; Iid Mujtahiddin, M.

    2016-11-01

    Observations of the meteorological variables have been conducted in Terentang coastal area, Central Bangka which is located in totality path of Total Solar Eclipse on March 9, 2016. These measurements were made before, during, and after the solar eclipse using a portable automatic weather station with 1 Hz data recording to investigate the influence of total solar eclipse on the incoming solar radiation and other weather variables. Due to the cloudiness at the first phase of the eclipse, the reduction of the radiation was not proportional to the percentage of the solar obscuration. Along with the disappearance of thick clouds, solar radiation changes reach the lowest value from 123 W/m2 to zero point at 5 minutes before the maximum phase. In contrast to the radiation decrement, decreasing air temperature was not comparable to the solar obscuration because it was not only determined by radiation, but also surrounding environment. High relative humidity, on average 89%, was discovered as an effect of the low atmospheric pressure which was affected by the insolation decline. The effect of total solar eclipse can be seen more clearly with spectrum analysis using Fourier transformation to identify periodogram patterns of each meteorology variable. This transformation produced a spectrum's peak totality which is higher than before and after the event on the insolation. The spectrum represents that total solar eclipse has considerable effect to the incoming solar radiation and others which is indicated by the change of the amplitude.

  2. A perspective about the total solar eclipse observation from future space settlements and a review of Indonesian space researches

    Science.gov (United States)

    Sastradipradja, D.; Dwivany, F. M.; Swandjaja, L.

    2016-11-01

    Viewing astronomy objects from space is superior to that from Earth due to the absence of terrestrial atmospheric disturbances. Since decades ago, there has been an idea of building gigantic spaceships to live in, i.e., low earth orbit (LEO) settlement. In the context of solar eclipse, the presuming space settlements will accommodate future solar eclipse chasers (amateur or professional astronomers) to observe solar eclipse from space. Not only for scientific purpose, human personal observation from space is also needed for getting aesthetical mental impression. Furthermore, since space science indirectly aids solar eclipse observation, we will discuss the related history and development of Indonesian space experiments. Space science is an essential knowledge to be mastered by all nations.

  3. The BAYSOFI Campaign - Measurements carried out during the total solar eclipse of August 11, 1999

    Directory of Open Access Journals (Sweden)

    Peter Fabian

    2001-05-01

    Full Text Available The total solar eclipse of August 11, 1999 provided a unique opportunity to observe the input of fast day-night and night-day transitions, under high solar elevation around noon, on the earth-atmosphere-biosphere system. Within the interdisciplinary field campaign BAYSOFI, measurements of radiation, boundary layer micrometeorology and photochemistry, photosynthesis and transpiration were carried out at Freising-Weihenstephan and several locations nearby focusing on short-term effects of the eclipse. Although the overall grosswetterlage on August 11 was not favourable for viewing the eclipse, with clouds covering most of central Europe, observational conditions at Weihenstephan were fair due to a large hole in the cloud layer which appeared just half hour before totality lasting for more than one hour. Thus significant effects of the eclipse on radiation, photolysis rates, OH, the temperature, wind, turbulence structure and stratification, ozone and CO2 fluxes, photosynthesis, transpiration and sap flow of trees could be observed which are reported and discussed in the following sequence of papers.

  4. Evidence of gravity waves into the atmosphere during the March 2006 total solar eclipse

    Directory of Open Access Journals (Sweden)

    C. S. Zerefos

    2007-09-01

    Full Text Available This study aims at providing experimental evidence, to support the hypothesis according to which the movement of the moon's shadow sweeping the ozone layer at supersonic speed, during a solar eclipse, creates gravity waves in the atmosphere. An experiment was conducted to study eclipse induced thermal fluctuations in the ozone layer (via measurements of total ozone column, ozone photolysis rates and UV irradiance, the ionosphere (Ionosonde Total Electron Content – ITEC, peak electron density height – hmF2, and the troposphere (temperature, relative humidity, before, during and after the total solar eclipse of 29 March 2006. We found the existence of eclipse induced dominant oscillations in the parameters related to the ozone layer and the ionosphere, with periods ranging between 30–40 min. Cross-spectrum analyses resulted to statistically significant square coherences between the observed oscillations, strengthening thermal stratospheric ozone forcing as the main mechanism for GWs. Additional support for a source below the ionosphere was provided by the amplitude of the oscillations in the ionospheric electron density, which increased upwards from 160 to 220 km height. Even though similar oscillations were shown in surface temperature and relative humidity data, no clear evidence for tropospheric influence could be derived from this study, due to the modest amplitude of these waves and the manifold rationale inside the boundary layer.

  5. Effects of a Solar Eclipse on the Propagation of VLF-LF Signals: Observations and Results

    Directory of Open Access Journals (Sweden)

    Barin Kumar De

    2011-01-01

    Full Text Available The results from the measurements of some of the fundamental parameters (amplitude of sferics and transmitted signal, conductivity of lower ionosphere of the ionospheric responses to the 22 July 2009 solar eclipse (partial: 91.7% are shown. This study summarizes our results from sferics signals at 81 kHz and subionospheric transmitted signals at 19.8 and 40 kHz recorded at Agartala, Tripura (latitude: 23¢XN, longitude: 91.4¢XE. We observed significant absorption in amplitude of these signals during the eclipse period compared to their ambient values for the same period during the adjacent 7 days. The signal strength along their propagation paths was controlled by the eclipse associated decrease in ionization in the D-region of the ionosphere. Waveguide mode theory calculations show that the elevation of the height of lower ionosphere boundary of the Earth-ionosphere waveguide to a value where the conductivity parameter was 106 unit. The absorption in 81 kHz sferics amplitude is high compared to the absorption in the amplitude of 40 kHz signal transmitted from Japan. The simultaneous changes in the amplitudes of sferics and in the amplitude of transmitted signals assert some sort of coupling between the upper atmosphere and the Earth¡¦s near-surface atmosphere prevailing clouds during solar eclipse.

  6. Ionospheric Response to the Total Solar Eclipse of 22 July 2009 as Deduced from VLBI and GPS Data

    Science.gov (United States)

    Guo, L.; Shu, F. C.; Zheng, W. M.; Kondo, T.; Ichikawa, R.; Hasegawa, S.; Sekido, M.

    2010-01-01

    A total solar eclipse occurred over China at latitudes of about 30 N on the morning of 22 July 2009, providing a unique opportunity to investigate the influence of the sun on the earth's upper ionosphere. GPS observations from Shanghai GPS Local Network and VLBI observations from stations Shanghai, Urumqi, and Kashima were used to observe the response of TEC to the total solar eclipse. From the GPS data reduction, the sudden decrease of TEC at the time of the eclipse, amounting to 2.8 TECU, and gradual increase of TEC after the eclipse were found by analyzing the diurnal variations. More distinctly, the variations of TEC were studied along individual satellite passes. The delay in reaching the minimum level of TEC with the maximum phase of eclipse was 5-10 min. Besides, we also compared the ionospheric activity derived from different VLBI stations with the GPS results and found a strong correlation between them.

  7. Search for Rapid Changes in the Visible-Light Corona during the 21 June 2001 Total Solar Eclipse

    OpenAIRE

    Rudawy, P.; Phillips, K. J. H.; Buczylko, A.; D. R., William; F. P. Keenan

    2010-01-01

    Some 8000 images obtained with the Solar Eclipse Coronal Imaging System (SECIS) fast-frame CCD camera instrument located at Lusaka, Zambia, during the total eclipse of 21 June 2001 have been analysed to search for short-period oscillations in intensity that could be a signature of solar coronal heating mechanisms by MHD wave dissipation. Images were taken in white-light and Fe xiv green-line (5303 ) channels over 205 seconds (frame rate 39 s(-1)), approximately the length of eclipse totality ...

  8. Solar-geothermal hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Lentz, Alvaro; Almanza, Rafael [Instituto de Ingenieria, UNAM, Ciudad Universitaria, Edificio 12, 04510 Mexico DF (Mexico)

    2006-10-15

    The Cerro Prieto Geothermal Power Plant is located in the northwest of Mexico, lat. 32{sup o}39', long. 115{sup o}21' in the northern hemisphere. A solar-geothermal hybrid system is proposed in order to increase the steam flow during the present geothermal cycle, adding a solar field of parabolic trough concentrators. Energy is supplied to the geothermal flow from wells in order to increase the steam generation rate. This configuration will increase the capacity factor of the system by generating additional steam during the peak demand hours. The parabolic trough solar field is evaluated in North-South and East-West orientation collector alignments. A proposal to obtain an increase of 10% in steam flow is evaluated, as the increase in flow is limited by the content of dissolved salts, so as to avoid a liquid phase with high salt concentrations. The size of the parabolic troughs field was obtained. (author)

  9. Analysis of the solar coronal green line profiles from eclipse observations

    CERN Document Server

    Prabhakar, Maya; Chandrasekhar, T

    2013-01-01

    Analysis of the solar coronal green line profiles reveals information regarding the physical conditions of the solar corona like temperature, density, Doppler velocity, non-thermal velocity etc. It provides insights to the unresolved problems like the coronal heating and the acceleration of the solar winds. Recent studies have reported excess blueshifts in the coronal line profiles and are interpreted as due to nanoflare heating, type II spicules and nascent solar wind flow. We have analyzed a time series of Fabry-Perot interferograms of the solar corona obtained during the total solar eclipse of 2001 June 21 from Lusaka, Zambia. The spatial behavior of the coronal green line profiles were examined and variations in intensity, linewidth, Doppler velocity and line asymmetry were obtained. Several line profiles showed asymmetry indicating the presence of multicomponents. Such line profiles were fitted with double Gaussian curves. It has been found that 42% of the line profiles were single components, 34% were b...

  10. Exposure to a solar eclipse causes neuronal death in the retina.

    Science.gov (United States)

    Thanos, S; Heiduschka, P; Romann, I

    2001-10-01

    A solar eclipse was observed in Europe on 11 August 1999. Several individuals suffered from transient or persisting retinal damage, caused by gazing at the eclipse without adequate eye protection. Retinal damage is the most serious hazard of exposure to light. but the mechanisms by which this type of exposure produces retinal damage and its cellular correlates are not yet established. We used an animal model to monitor the mechanisms of retinal damage following excessive light exposure, and in particular to study whether observation of the eclipse induces death of retinal cells. In the geographic area where the experiment was conducted, a partial (90%) solar eclipse was observed. Experimental albino rats were exposed to these eclipse conditions, and control rats were exposed to normal sunlight. Another group of control animals was exposed to the same conditions, but was provided with protective light filters of the type recommended for human use. The DNA fragmentation in retinal sections of the various groups was analysed by terminal deoxynucleotidyl-transferase-mediated dUTP nick-end labelling. This analysis revealed that exposure to both normal sunlight and to the eclipse resulted in neuronal apoptosis. Immunohistochemical techniques were used to evaluate possible glial-vascular alterations. Dying cells could first be detected 24 h after exposure, the largest number of which were found 6 days later in the photoreceptor layer. Control levels were attained 14 days after the exposure. Retinal ganglion cells underwent apoptosis in both groups (normal sunlight and eclipse exposure), whereas in the neuroglial cells there was an up-regulation of the intermediate filament content. The number of dying cells in both groups was greater in animals whose pupils had been dilated pharmacologically during exposure. On the other hand, the protective filters were effective in preserving the rat retinal cells from apoptosis. These results show, for the first time, that the cellular

  11. Impacts of the solar eclipse of 29 March 2006 on the surface ozone and nitrogen dioxide concentrations at Athens, Greece

    Directory of Open Access Journals (Sweden)

    C. Tzanis

    2007-10-01

    Full Text Available The behavior of surface ozone and nitrogen dioxide concentration as well as the variations in various meteorological parameters before, during and after the total solar eclipse of 29 March 2006 has been examined. This analysis is based on measurements performed at four stations located in the greater Athens basin in Greece. The experimental data demonstrated that the solar eclipse phenomenon affects the surface ozone and nitrogen dioxide concentrations as well as the temperature, the relative humidity and the wind speed near the ground. The reduction of the solar ultraviolet radiation at 312 and 365 nm reached 97% and 93% respectively, while the air temperature dropped, the relative humidity increased and the wind speed decreased. The percentage change (decrease of surface ozone concentration was maximized one hour after the maximum phase of the eclipse due to the decreased efficiency of the photochemical ozone formation. The surface nitrogen dioxide concentration increased and the time lag of the nitrogen dioxide response to the solar eclipse was found to be different for each station. A plausible cause for the increase in NO2 concentration may be the conversion of NO to NO2 through reaction with pre-existing O3 along with the low photolysis rates of NO2 as a consequence of the decreased solar radiation during the solar eclipse event.In general, the time response to the eclipse phenomenon was different for each of the aforementioned parameters.

  12. Coronal structure and brightness profile of the total solar eclipse on August 1,2008

    Institute of Scientific and Technical Information of China (English)

    ZHAO HaiBin; LIN QiSheng; CHEN YiPing; JIN Sheng; GUAN ZhenBiao; HU Zhongwei

    2009-01-01

    Solar corona is the outermost part of the solar atmosphere.Coronal activities influence space environment between the Sun and the Earth,space weather and the Earth itself.The total solar eclipse (TSE) is the best opportunity to observe the solar corona on ground.During the TSE 2008,a series of images of the corona and partial eclipse of solar disk were obtained using telescope and CCD camera.After image processing,preliminary results of coronal structure are given,and radial brightness profiles of the corona in directions of pole and equator of the Sun are measured.Though in solar activity minimum,the shape and structure of the corona are not symmetry.The equatorial regions are more extent than the polar one,and there are also larger differences between the east and west equatorial regions and between the south and north polar regions.Coronal streamers on east side of the equator,particularly the largest one in east-south direction,are very obvious.The coronal plume in south polar region consists of more polar rays than that in north polar region.These structures are also shown in other observations and data of SOHO.The radial brightness profiles in directions of pole and equator are similar to those of the Van de Hulst model in solar minimum,but there are a few differences due to coronal activity,which is shown in the isophote map of the corona.

  13. Exploring the Physics of the Corona with Total Solar Eclipse Observations

    CERN Document Server

    Habbal, Shadia R; Daw, Adrian; Ding, Adalbert; Druckmuller, Miloslav; Esser, Ruth; Johnson, Judd; Morgan, Huw

    2011-01-01

    This white paper is a call for a concerted effort to support total solar eclipse observations over the next decade, in particular for the 21 August 2017 eclipse which will traverse the US continent. With the recent advances in image processing techniques and detector technology, the time is ripe to capitalize on the unique diagnostic tools available in the visible and near infrared wavelength range to explore the physics of the corona. The advantage of coronal emission lines in this wavelength range, over their extreme ultraviolet counterparts, is (1) the significant radiative component in their excitation process (in addition to the collisional excitation), which allows for observations out to a few solar radii, (2) the higher spectral selectivity available for imaging, giving well-defined temperature responses for each bandpass (one line as opposed to many), and (3) the capability of polarization measurements in a number of spectral lines. Consequently, the evolution of the thermodynamic and magnetic proper...

  14. Magneto-ionospheric effects of the solar eclipse of March 20, 2015, over Kharkov

    Science.gov (United States)

    Chernogor, L. F.; Garmash, K. P.

    2017-01-01

    The results of observations of disturbances in the lower and middle ionosphere and in the geomagnetic field accompanying the partial solar eclipse over Kharkov are presented. The ionospheric effects have been studied with the use of an ionosonde and measurements of the phase and amplitude of a radio signal with a frequency of 66.(6) kHz on the Moscow-Kharkov route, and the effects in the magnetic field have been analyzed with the help of a magnetometer-fluxmeter in the range of periods from 1 to 1000 s. Disturbances in both the lower and middle ionosphere, as well as in the geomagnetic field, have been detected. The observation results have been compared with the results of a simulation of physical processes accompanying the solar eclipse. A good agreement has been found between observational and modeling results.

  15. First Report on the 2016 March 9 Total Solar Eclipse Observations

    Science.gov (United States)

    Pasachoff, Jay M.

    2016-06-01

    Totality swept across Indonesia and into the Pacific on 2016 March 9, lasting up to 2 min 45 s on Ternate in the Spice Islands (Malukus). I provide a first report on our observations. Our scientific goal is to follow changes in the corona over the solar-activity cycle, now past its 2012 and 2014 double peak, and to measure temporal changes in the corona on the scale of minutes or hours by comparing eclipse observations made at several sites along the path. I also discuss the near-simultaneous coronal observations made with SOHO/LASCO, SDO/AIA, STEREO/SECCHI, PROBA2/SWAP, and Hinode XRT.For the forthcoming 2017 eclipse, we acknowledge grants to JMP and Williams College from the Solar Terrestrial Program of the Atmospheric and Geospace Sciences Division of the National Science Foundation and from the Committee for Research and Exploration of the National Geographic Society.

  16. Investigation of the solar wind outflows and joint observations during the total solar eclipse of March 29, 2006

    Science.gov (United States)

    Abbo, Lucia; Zangrilli, Luca; Antonucci, Ester; Fineschi, Silvano; Kohl, John; Giordano, Silvio; Massone, Giuseppe; Capobianco, Gerardo; Calcidese, Paolo; Porcu, Francesco

    During the total solar eclipse of 29 March 2006, SOHO observations of JOP158 were coordinated with ground based instruments. In particular, the Ultraviolet Coronagraph Spectrometer (UVCS) onboard SOHO has observed the south coronal hole in the OVI doublet emission in order to probe the role of plume and interplume regions in the dynamics of the fast solar wind. From the analysis of the polarized K-solar corona measurements obtained with the EKPol polarimeter from the site of c (desert of Sahara, Lybia), we estimate the coronal electron density radial profiles and perform a Doppler dimming analysis of the OVI doublet line intensities to measure the outflow velocity.

  17. Celebrating the Eighth Annual International Observe the Moon Night and Supporting the 2017 Solar Eclipse

    Science.gov (United States)

    Buxner, Sanlyn; Jones, Andrea; Bleacher, Lora; Shaner, Andy; Wenger, Matthew; Bakerman, Maya; Joseph, Emily; Day, Brian; White, Vivian; InOMN Coordinating Committee

    2017-01-01

    2017 marks the eighth International Observe the Moon Night (InOMN), which will be held on July 15, 2017. We will present findings from the first seven years, including the most recent figures from the October 2016 event, and provide an overview of the 2017 events which will support the Great American Eclipse which occurs about five weeks later, on August 21, 2017.InOMN is an annual worldwide public event that encourages observation, appreciation, and understanding of our Moon and its connection to NASA planetary science and exploration. This year InOMN’s event will support broad efforts to promote the eclipse by providing resources to help InOMN hosts highlight lunar science that will influence the eclipse, such as the topography of the Moon, which affects the edges of the eclipse path and the location and duration of Baily’s beads. The InOMN team will host webinars to discuss the Moon, lunar science, and lunar and solar eclipses.Each year, thousands of visitors take part in hundreds of events across the world. In the first seven years (2010 to 2016) over 3,700 events were registered worldwide and hosted by a variety of institutions including astronomy clubs, observatories, schools, and universities and held at a variety of public and private institutions all over the world including museums, planetaria, schools, universities, observatories, parks, and private businesses and homes. Evaluation of InOMN reveals that events are raising visitors’ awareness of lunar science and exploration, providing audiences with information about lunar science and exploration, and inspiring visitors to want to learn more about the Moon and providing connections to opportunities to do so.InOMN is sponsored by NASA's Lunar Reconnaissance Orbiter, NASA's Solar System Exploration Research Virtual Institute (SSERVI), and the Lunar and Planetary Institute. Learn more and register to host an event at http://observethemoonnight.org/.

  18. Rocket observations of solar radiation during the eclipse of 26 February 1979

    Science.gov (United States)

    Bliss, H. M.; Smith, L. G.

    1980-01-01

    Three Nike Tomahawk rockets were launched in Red Lake, Ontario, one previous to, and two during, the total eclipse of the Sun, for the purpose of studying the atmosphere and its interaction with solar radiation. The method and preliminary results of three experiments that were used to measure solar radiation in the X-ray, Lyman-alpha, and visible parts of the spectrum are described. The instrumentation designed for this investigation is discussed as well as post-flight data processing techniques. The retrieved data were processed to some extent to verify that a valid representation of the solar radiation was obtained. The Lyman-alpha experiment yielded very good results, and preliminary data are included. The visible radiation experiment served as support for the other experiments and also functioned well. Due to a high level of energetic particles during the eclipse, the X-ray data were contaminated and are not presented. However, satellite observations indicate no appreciable level of X-rays from the Sun during the time of the eclipse.

  19. Effects of total solar eclipse of 29 March 2006 on surface radiation

    Directory of Open Access Journals (Sweden)

    S. Kazadzis

    2007-06-01

    Full Text Available Solar irradiance spectral measurements were performed during a total solar eclipse. The spectral effect of the limb darkening to the global, direct irradiance and actinic flux measurements was investigated. This effect leads to wavelength dependent changes in the measured solar spectra showing a much more pronounced decrease in the radiation at the lower wavelengths. Radiative transfer model results were used for the computation of a correction for the total ozone measurements due to the limb darkening. This correction was found too small to explain the large decrease in total ozone column derived from the standard Brewer measurements, which is an artifact in the measured irradiance due to the increasing contribution of diffuse radiation against the decreasing direct irradiance caused by the eclipse. Calculations of the Extraterrestrial spectrum and the effective sun's temperatures, as measured from ground based direct irradiance measurements, showed an artificial change in the calculations of both quantities due to the fact that radiation coming from the visible part of the sun during the eclipse phases differs from the back body radiation described by the Planck's law.

  20. Ionospheric response to total solar eclipse of 22 July 2009 in different Indian regions

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2013-09-01

    Full Text Available The variability of ionospheric response to the total solar eclipse of 22 July 2009 has been studied analyzing the GPS data recorded at the four Indian low-latitude stations Varanasi (100% obscuration, Kanpur (95% obscuration, Hyderabad (84% obscuration and Bangalore (72% obscuration. The retrieved ionospheric vertical total electron content (VTEC shows a significant reduction (reflected by all PRNs (satellites at all stations with a maximum of 48% at Varanasi (PRN 14, which decreases to 30% at Bangalore (PRN 14. Data from PRN 31 show a maximum of 54% at Kanpur and 26% at Hyderabad. The maximum decrement in VTEC occurs some time (2–15 min after the maximum obscuration. The reduction in VTEC compared to the quiet mean VTEC depends on latitude as well as longitude, which also depends on the location of the satellite with respect to the solar eclipse path. The amount of reduction in VTEC decreases as the present obscuration decreases, which is directly related to the electron production by the photoionization process. The analysis of electron density height profile derived from the COSMIC (Constellation Observing System for Meteorology, Ionosphere & Climate satellite over the Indian region shows significant reduction from 100 km altitude up to 800 km altitude with a maximum of 48% at 360 km altitude. The oscillatory nature in total electron content data at all stations is observed with different wave periods lying between 40 and 120 min, which are attributed to gravity wave effects generated in the lower atmosphere during the total solar eclipse.

  1. Effects of total solar eclipse of 29 March 2006 on surface radiation

    Directory of Open Access Journals (Sweden)

    S. Kazadzis

    2007-11-01

    Full Text Available Solar irradiance spectral measurements were performed during a total solar eclipse. The spectral effect of the limb darkening to the global, direct irradiance and actinic flux measurements was investigated. This effect leads to wavelength dependent changes in the measured solar spectra showing a much more pronounced decrease in the radiation at the lower wavelengths. Radiative transfer model results were used for the computation of a correction for the total ozone measurements due to the limb darkening. This correction was found too small to explain the large decrease in total ozone column derived from the standard Brewer measurements, which is an artifact in the measured irradiance due to the increasing contribution of diffuse radiation against the decreasing direct irradiance caused by the eclipse. Calculations of the Extraterrestrial spectrum and the effective sun's temperatures, as measured from ground based direct irradiance measurements, showed an artificial change in the calculations of both quantities due to the fact that radiation coming from the visible part of the sun during the eclipse phases differs from the black body radiation described by the Planck's law.

  2. Nanostructured organic and hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Weickert, Jonas; Dunbar, Ricky B.; Hesse, Holger C.; Wiedemann, Wolfgang; Schmidt-Mende, Lukas [Department of Physics and Center for NanoScience (CeNS), Ludwig-Maximilians University (LMU) Munich, Amalienstr. 54, 80799 Munich (Germany)

    2011-04-26

    This progress report highlights recent developments in nanostructured organic and hybrid solar cells. The authors discuss novel approaches to control the film morphology in fully organic solar cells and the design of nanostructured hybrid solar cells. The motivation and recent results concerning fabrication and effects on device physics are emphasized. The aim of this review is not to give a summary of all recent results in organic and hybrid solar cells, but rather to focus on the fabrication, device physics, and light trapping properties of nanostructured organic and hybrid devices. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. White light corona during total solar eclipse on March 9, 2016

    Science.gov (United States)

    Imaduddin, Irfan; Akbar, Evan I.; Putri, Gerhana P.

    2016-11-01

    We observed the white-light corona during the total solar eclipse of 2016 March 9 from Corong Beach, East Borneo. The solar corona is nearly circular with exception on the southern part of the Sun. Coronal structures are clearly seen. Based on the data, we obtained the Ludendorff flattening index, Nikolsky geometric flattening index, and phases of solar activity (Φ and P) are 0.129, 1.32, -0.716, and 0.573 respectively. Relation between Ludendorff and Nikolsky index, sunspot number, and phases of solar activity were discussed. We also predicted the amplitude of solar cycle 25 to be 196 ± 52 (based on 13-month smoothed monthly data) and 130 ± 42 (based on monthly sunspot number data).

  4. Ocular surface changes and tear film alterations associated with sun gazing during a solar eclipse.

    Science.gov (United States)

    Nepp, Johannes; Dorner, Guido T; Jandrasits, Kerstin; Maar, Noemi; Schild, Gebtraud; Wedrich, Andreas

    2003-01-31

    A solar eclipse occurred in central Europe on August 11th, 1999. Following the eclipse, patients with ocular symptoms were investigated. Gazing at the sun without protection is liable to damage the retina. Our attention was focused on changes of the ocular surface and the tear film. Forty-three patients were investigated within one week after the solar eclipse as baseline. 33 of them were followed up one year later. Visual acuity and the central visual-field were measured, and the ocular surface and the fundus were examined using a slit lamp. The quality of the lacrimal tear film was examined using Schirmer's test for the aqueous layer, break-up time for the mucous layer and interference observation for the lipid layer, measured by a slit lamp and a tearoscope. At the baseline 19 patients had non-specific visual problems. Pathological alterations of the tear film were seen in all three tear-film layers: Schirmer's test was pathological in 87%, break-up time decreased in 85%, the interference pattern of the lipid layer changed in 67% and there were changes in 87% using the tearoscope. One year later the non specific visual disorders had disappeared. Schirmer's test did not reveal much change from the baseline: 51% pathological, 24% remained pathological in break-up-time and the lipid layer was normalized except in 9%. Using the tearoscope, lipids were better than grade 3 in all patients. After gazing at a solar eclipse the ocular surface and tear film changed. While the aqueous layer remained pathological in many patients, the lipid layer and the mucous layer recovered spontaneously.

  5. Spatiotemporal change of sky polarization during the total solar eclipse on 29 March 2006 in Turkey: polarization patterns of the eclipsed sky observed by full-sky imaging polarimetry.

    Science.gov (United States)

    Sipocz, Brigitta; Hegedüs, Ramón; Kriska, György; Horváth, Gábor

    2008-12-01

    Using 180 degrees field-of-view (full-sky) imaging polarimetry, we measured the spatiotemporal change of the polarization of skylight during the total solar eclipse on 29 March 2006 in Turkey. We present our observations here on the temporal variation of the celestial patterns of the degree p and angle alpha of linear polarization of the eclipsed sky measured in the red (650 nm), green (550 nm), and blue (450 nm) parts of the spectrum. We also report on the temporal and spectral change of the positions of neutral (unpolarized, p = 0) points, and points with local minima or maxima of p of the eclipsed sky. Our results are compared with the observations performed by the same polarimetric technique during the total solar eclipse on 11 August 1999 in Hungary. Practically the same characteristics of celestial polarization were encountered during both eclipses. This shows that the observed polarization phenomena of the eclipsed sky may be general.

  6. Broadband Spectroscopy of the Corona during the Total Solar Eclipse of March 29, 2006

    Science.gov (United States)

    Jaeggli, Sarah A.; Habbal, S. R.; Kuhn, J. R.; Nayfeh, M. H.

    2006-12-01

    We present coronal observations from the total solar eclipse of 29 March 2006 taken near Waw al Namus, Libya. During the 4 minutes and 6 seconds of totality, observations were made with a tracking collecting mirror and fiber-fed spectrograph. The spectrograph used is a high quantum efficiency commercial Ocean Optics QE65000 Spectrometer with a wavelength range of 350 to 1100 nm, and spectral resolution of about 0.75 nm. High quantum efficiency allowed for many short exposures of the inner (100 msec) and outer (10,000 msec) corona during the eclipse. Important spectral features, and the difference in color between the inner and outer corona are identified. Atmospheric contributions are discussed. Likely candidates for the nature of dust grains contributing to the F-corona measurements are also presented. These are compared with laboratory spectra of silicon nanoparticles.

  7. VLF signal perturbation due to the total solar eclipse of March 2015

    Science.gov (United States)

    Nait Amor, Samir; Bouderba, Yasmina

    2016-07-01

    On March 20 2015 a total Solar eclipse occurred and covered several regions in north America, Greenland, west of Europe and north Africa with different occultation rates. During this event, many VLF paths recorded at Algiers receiver were perturbed. In this contribution, we will present a qualitative analysis of two paths (GQD and DHO) which were disturbed differently since the occultation rate at the transmitter locations was different. In addition to the qualitative study, we determined the newly formed reference height and β values at different times during the eclipse transit. From these determined parameters the time profile of the electron density is then deduced. The results showed that the new reference height, β and the electron density are different from one transmitter analysis to other due to the occultation rate difference.

  8. Predicting the Structure of the Solar Corona for the Total Solar Eclipse of March 29,2006

    Science.gov (United States)

    Mikic, Z.; Linker, J. a.; Lionello, R.; Riley, P.; TItov, V.

    2007-01-01

    We describe the use of a three-dimensional MHD model to predict the s tructure of the corona prior to the total solar eclipse of March 29, 2006. The calculation uses the observed photospheric radial magnetic f ield as a boundary condition. We use a new version of our model that has an improved description of energy transport in the corona. The mo del allows us to predict the emission of X-ray and EUV radiation in t he corona. We compare the predicted polarization brightness in the co rona with four observations of the eclipse from Greece, Egypt, and Li bya, and we demonstrate that the model accurately predicts the largescale structure of the corona. We also compare X-ray emission from the model with GOES/SXI images.

  9. Predicting the Structure of the Solar Corona for the Total Solar Eclipse of March 29,2006

    Science.gov (United States)

    Mikic, Z.; Linker, J. a.; Lionello, R.; Riley, P.; TItov, V.

    2007-01-01

    We describe the use of a three-dimensional MHD model to predict the s tructure of the corona prior to the total solar eclipse of March 29, 2006. The calculation uses the observed photospheric radial magnetic f ield as a boundary condition. We use a new version of our model that has an improved description of energy transport in the corona. The mo del allows us to predict the emission of X-ray and EUV radiation in t he corona. We compare the predicted polarization brightness in the co rona with four observations of the eclipse from Greece, Egypt, and Li bya, and we demonstrate that the model accurately predicts the largescale structure of the corona. We also compare X-ray emission from the model with GOES/SXI images.

  10. Corona during the total solar eclipse on March 20, 2015, and 24 cycle development

    Science.gov (United States)

    Yazev, Sergey; Mordvinov, Aleksandr; Dvorkina-Samarskaya, Antonina

    2016-06-01

    We analyzed the structure of coronal features, using data on the March 20, 2015 total solar eclipse. The Ludendorff index characterizing the flattening of the corona is 0.09. The solar corona structure in the Northern and Southern hemispheres corresponds to the maximum and post-maximum phases of solar activity, respectively. The asynchronous development of magnetic activity in the Sun's Northern and Southern hemispheres caused a substantial asymmetry of coronal features observed at the reversal of polar magnetic fields in the current cycle. The polar ray structures in the Southern Hemisphere are associated with the polar coronal hole, while in the Northern Hemisphere a polar hole has not been formed yet. We examine the relation between large-scale magnetic fields and location of high coronal structures.

  11. [A strategy for preventing health injuries due to observing the solar eclipse in Mexico].

    Science.gov (United States)

    Juan-López, M; Peña-Corona, M P

    1993-01-01

    A total solar eclipse was watched by almost [corrected] 50 million people in the Mexican Republic on July 11, 1991. Cases of solar retinitis, which can even lead to permanent loss of visual function, have been reported in the international literature. The institutions of the National Health System employed a strategy for the prevention of risks and health damages caused by direct observation of the phenomenon, which implied the elaboration of a technical norm concerning the manufacturing of sun filters, the diffusion of preventive actions through the use of mass media, the detection and prompt care of cases and the establishment of an ophthalmologic care system and epidemiological surveillance system. The result was the detection of 21 moderate cases of solar retinitis, all of which recovered their full visual function after four months. The present article reports the implemented actions and the details of the cases.

  12. Spectro-Imaging Polarimetry of the Local Corona During Solar Eclipse

    Science.gov (United States)

    Qu, Z. Q.; Dun, G. T.; Chang, L.; Murray, G.; Cheng, X. M.; Zhang, X. Y.; Deng, L. H.

    2017-02-01

    Results are presented from spectro-imaging polarimetry of radiation from the local solar corona during the 2013 total solar eclipse in Gabon. This polarimetric observation was performed from 516.3 nm to 532.6 nm using a prototype Fiber Arrayed Solar Optical Telescope (FASOT). A polarimetric noise level on the order of 10^{-3} results from a reduced polarimetric optical switching demodulation (RPOSD) procedure for data reduction. It is revealed that the modality of fractional linear polarization profiles of the green coronal line shows a diversity, which may indicate complex mechanisms. The polarization degree can approach 3.2 % above the continuum polarization level on a scale of 1500 km, and the nonuniform spatial distribution in amplitude and polarization direction is found even within a small field of view of 7500 km. All of this implies that the coronal polarization is highly structured and complex even on a small scale.

  13. No evidence of a circumsolar dust ring from infrared observations of the 1991 solar eclipse.

    Science.gov (United States)

    Lamy, P; Kuhn, J R; Lin, H; Koutchmy, S; Smartt, R N

    1992-09-04

    During the past 25 years there have been many attempts to detect a possible dust ring around the sun, with contradictory results. Before the 1991 eclipse, infrared eclipse experiments used single-element detectors to scan the corona along the ecliptic for excess surface brightness peaks. The availability of relatively large-format infrared array detectors now provides a considerable observational advantage: two-dimensional mapping of the brightness and polarization of the corona with high photometric precision. The 1991 eclipse path included the high-altitude Mauna Kea Observatory, a further advantage to measure the corona out to large angular distances from the sun. Results are reported from an experiment conducted on Mauna Kea with a HgCdTe-array detector sensitive to wavelengths between 1 and 2.5 micrometers, using broad-band J, H, and K filters. Although the sky conditions were not ideal, the H- and K-band surface brightnesses clearly show the inhomogeneous structure in the K-corona and the elliptical flattening of the F-corona, but no evidence of a circumsolar, local dust component out to 15 solar radii.

  14. The 20 March 2015 total solar eclipse: effects in the high-latitude lower ionosphere

    Science.gov (United States)

    Cherniakov, Sergey; Tereshchenko, Valentina; Ogloblina, Olga; Vasiliev, Evgeny; Gomonov, Alexander

    2016-07-01

    The medium-wave facility of partial reflections of the Polar Geophysical Institute (observatory "Tumanny", 69 N, 35.7 E) has observed behavior of the lower high-latitude ionosphere during the 20 March 2015 total solar eclipse. There were several effects during the eclipse. Generally on the heights of the lower ionosphere the "short night" effect had shown, but at some heights local enhanced electron concentration were revealed and the behavior of the electron concentration had the wave-like form. It had seen also at the behavior of the total electron content of the lower ionosphere. The periods and behavior of the wave are considered. It can be explained by influence of acoustic-gravity waves which originated after cooling of the atmosphere by the lunar shadow during its supersonic movement along the earth surface. The periods and behavior of waves during the eclipse were also received using riometer data at the observatory "Tumanny" and the magnetometer at the observatory "Loparskaya" (68.63 N, 33.38 E).

  15. UNAWE Indonesia project: raising total solar eclipse 2016 awareness through educational packages

    Science.gov (United States)

    Handini, A. T.; Yulianty, Y.; Premadi, P. W.; Annafi, A.

    2016-11-01

    On March 9th 2016, some regions in Indonesia witnessed the Total Solar Eclipse (TSE). At that time, Indonesia was the only mainland in the world that could observe TSE. This moment is extraordinary because its probability of being observed at the same point happens every 350 years. On a purpose of raising public awareness and engaging more participations, UNAWE Indonesia developed a handy material and sent the so called educational packages which provided essential information about eclipse, especially TSE. Each package contains of modul of TSE study and materials for simple TSE activity so people who received the package could observe TSE safely. In the delivery of this program, we established a collaboration partner, whom are teachers, as an 'eclipse ambassador'. The local partners were responsible for socializing the information for school or their community. We encouraged them to conduct an observation activity and ask them to fill an evaluation report. As a result, 48 out of 59 partners or equal to 81.3% of all partners has sent the evaluation of the package and documentation of the activity during TSE. They responded positively as it was easy to understand, functional, and convenient.

  16. [The logic of a traditional health belief: solar eclipse and pregnancy in Ocuituco, Mexico].

    Science.gov (United States)

    Castro, R

    1995-01-01

    An analysis of the logic of one of the commonest health beliefs in rural areas of Mexico is made, taking as a starting point testimonies collected in the area of Ocuituco, in the state of Morelos. This belief suggests that a pregnant woman is in danger of having a harelipped baby during a solar eclipse. The importance of the knowledge about the logic of this kind of beliefs is discussed from a public health perspective. These beliefs are associated with specific forms of suffering and give way to particular preventive measures which must be taken into account if the efficacy of health programs is to be increased. The interrelation of these beliefs with other traditional elements (such as the "loss of the shadow" and the "hot-cold theory") is discussed. Also, some of the already existing interpretations of this belief which seek to link the "loss of the shadow" with the solar eclipse belief are reviewed. Finally, an alternative interpretation of this belief is made from a structuralist methodological perspective. This interpretation is grounded in the Nahuatl myth on the creation of the sun and the moon, and in an analysis of the nature of rabbits in the Nahuatl culture, according to historic secondary sources. It is suggested that the belief about the danger of a solar eclipse must be interpreted in connection to the "hot-cold theory", but not to the "loss of the shadow". This paper concludes by emphasizing the importance of this type of research within the public health field, as it enables us both to understand the underlying logic of this type of conceptions, and to reinforce the dialogue between modern and alternative medicine, so that the daily encounter between these two types of medicine can be facilitated.

  17. OCT findings in patients with retinopathy after watching a solar eclipse.

    Science.gov (United States)

    Codenotti, Marco; Patelli, Fabio; Brancato, Rosario

    2002-01-01

    To evaluate the optical coherence tomography (OCT) findings in patients with solar retinopathy after watching a solar eclipse. Complete ocular examinations and OCT were done in 4 patients presenting with acute solar retinopathy soon after observation of an eclipse. All 4 patients repeated the examinations about 1 month and 1 year after the first visit. The symptoms and fundus findings were similar in all patients; all eyes were emmetropic. However, the OCT images were different in all patients, and the alterations were at different levels. The most evident alterations shown by OCT were: a reduction in the intensity of reflectiveness of the retinal pigment epithelium in 3 cases; intraretinal nonreflective spaces between the inner retinal layers in 2 cases; increased reflectiveness of the inner retinal layers in 2 cases, and a round hyperreflective formation in the vitreous just in front of the fovea in 1 case. All these OCT alterations disappeared after 1 month. The retinal damage arising soon after exposure to sunlight showed many different aspects in the OCT images of the 4 cases examined. All retinal layers seemed to be altered, but these alterations disappeared after 1 month, and the OCT findings remained the same after 1 year. Copyright 2002 S. Karger AG, Basel

  18. Solar diameter, eclipses and transits: the importance of ground-based observations

    CERN Document Server

    Sigismondi, Costantino

    2012-01-01

    According to satellite measurements the difference between polar and equatorial radius does not exceed 10 milliarcsec. These measurements are differential, and the absolute value of the solar diameter is not precisely known to a level of accuracy needed for finding variations during years or decades. Moreover the lifetime of a satellite is limited, and its calibration is not stable. This shows the need to continue ground-based observations of the Sun exploiting in particular the methods less affected by atmospheric turbulence, as the planetary transits and the total and annular eclipses. The state of art, the advantages and the limits of these two methods are here considered.

  19. Research of propagation the high frequency signals during total solar eclipses

    Science.gov (United States)

    Ryabova, Mariya; Ivanov, Vladimir; Ivanov, Dmitrii; Riabova, Natalia; Elsukov, Aleksei

    Vertical-oblique sounding methods are special importance for the study; they provide data on the electron concentration. In panoramic sounders, the mean frequencies of sounding signals vary consequently in the range of apriori uncertainty of the conditions of their reflection from the ionosphere. The aim of this work is the experimental study of the variations in the MUFs along one-hop HF lines during the total solar eclipses, and their application for the estimation of the effective recombination coefficient. To solve the above problem, experiments were carried out with the use of a chirp sounder manufactured at the Volga State University of Technology. The main advantages of chirp sounder are connected with the use of continuous chirps, which allow for the use of methods of optimal reception when deciphering in a frequency region, which provides for a signal-to-noise ratio acceptable for obtaining reliable results. We carried out experiments on oblique chirp sounding of the ionosphere during the total solar eclipse of March 29, 2006, and on the reference days of March 28 and 30, 2006, as well as during the total solar eclipse of August 1, 2008, and the reference days of July 31 and August 2, 2008. The ionosonde transmitters were located in Great Britain (the town of Inskip), Cyprus, and Irkutsk, and the receiver was located in Yoshkar-Ola. The maximal phases of the eclipse of March 29 at the target sounding point (TSP) were 0.89 for Cyprus-Yoshkar-Ola (observed at 11:15 UT) and 0.49 for Inskip-Yoshkar-Ola (observed at 11:03 UT); for the eclipse of August 1, 1 for Irkutsk-Yoshkar-Ola (observed at 11:36 UT). Based on the primary data (ionograms), the secondary data were determined in automatic mode. In particular, diurnal variations in the MUF of the 1F2 and 2F2 modes were calculated for the eclipse periods and the reference days along different radio paths. Variation in the MUF on the reference days required the use of a smoothing procedure, which was carried out

  20. Future hybrid systems: solar and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kazmerski, L.L. [National Renewable Energy Lab., Golden, CO (United States); Broussard, K. [National Renewable Energy Lab., Golden, CO (United States)]|[NREL MURA Intern from Southern Univ., Baton Rouge, LA (United States)

    2003-07-01

    Future solar and hydrogen hybrid systems are discussed in terms of the evolving hydrogen economy. The focus is on distributed hydrogen, relying on the same distributed-energy strengths of solar-photovoltaic electricity in the built environment. Solar-hydrogen residences, as well as solar parks, are presented. Landarea issues are evaluated, and the economics and potential of these approaches are examined in terms of roadmap predictions on PV and hydrogen pathways. (orig.)

  1. The Influence of a solar eclipse on temperature and wind in the Upper-Rhine Valley - A numerical case study

    Directory of Open Access Journals (Sweden)

    Bernhard Vogel

    2001-05-01

    Full Text Available The effects on temperature and wind caused by the solar eclipse of August 11, 1999 in the south western part of Germany were simulated. While during the real event clouds and precipitation were present in most of the model domain cloud free conditions are assumed for the simulation. A temperature decrease of up to 7K was simulated during the eclipse event close to the surface. Thermal stability changes from unstable to stable conditions and the temperature gradient reaches values which are comparable to those normally found after sunset. Temperature keeps about 1K lower after the eclipse event during the rest of the day. Boundary layer height shortly after the eclipse event differs by several hundred meters. The effects on wind speed are rather small with the exception of the slopes of the mountains and in the vicinity of Lake Constance.

  2. Solar Eclipse Monitoring for Solar Energy Applications Using the Solar and Moon Position Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Reda, I.

    2010-03-01

    This report includes a procedure for implementing an algorithm (described by Jean Meeus) to calculate the moon's zenith angle with uncertainty of +/-0.001 degrees and azimuth angle with uncertainty of +/-0.003 degrees. The step-by-step format presented here simplifies the complicated steps Meeus describes to calculate the Moon's position, and focuses on the Moon instead of the planets and stars. It also introduces some changes to accommodate for solar radiation applications.

  3. Amazonia Introduced to General Relativity: The May 29, 1919, Solar Eclipse from a North-Brazilian Point of View

    Science.gov (United States)

    Crispino, Luís C. B.; de Lima, Marcelo C.

    2016-12-01

    In 1919, A. C. D. Crommelin and C. R. Davidson, British astronomers from the Greenwich Observatory in England, passed by Amazonia on their Brazilian journey aiming to measure the bending of stars' light rays during the total solar eclipse of May 29, 1919, and thereby put the theory of general relativity to the test. In the context of Crommelin's and Davidson's visit, we discuss how Amazonia was introduced to Einstein's theory of gravitation, and also the observations and repercussions of the May 29, 1919, solar eclipse in Belém, capital city of the North-Brazilian Pará state.

  4. Temperature perturbations in the troposphere-stratosphere over Thumba (8.5° N, 76.9° E during the solar eclipse 2009/2010

    Directory of Open Access Journals (Sweden)

    K. V. Subrahmanyam

    2011-02-01

    Full Text Available Measurements of atmospheric temperature profiles in the troposphere and lower stratosphere were made over Thumba Equatorial Rocket Launching Station (TERLS (8.5° N, 76.9° E during a partial solar eclipse (22 July 2009 and an annular solar eclipse (15 January 2010. It was observed that during the partial solar eclipse, the temperature decreased by 2–3 °C in the vicinity of the tropopause and in the lower stratosphere the temperature increased by ~2.6 °C during the maximum phase of the partial solar eclipse. During the annular solar eclipse, a temperature reduction of ~2 °C was observed around the tropopause. This study also revealed a feature of delayed effect in the form of a very intense warming of ~8 °C at 18 km after about 4 h of the annular solar eclipse. The Cold-Point Tropopause (CPT temperature increased slowly before the beginning of the eclipse (up to 10:00 IST and during the maximum phase of the eclipse, the difference in CPT temperature and height was −3.5 °C and ~110 m, respectively, as that of the control day. After the four hours of the eclipse, the CPT height had decreased by ~1.7 km and the CPT temperature increased by ~4.6 °C. This is for the first time that the diurnal variation of the tropopause has been reported during a solar eclipse day. The present study, thus, provided an opportunity to investigate the temperature perturbations in the troposphere and lower stratosphere during a partial and annular solar eclipse. The highlight of the present results are (1 cooling of the entire troposphere and lower stratosphere during the maximum phase of annular solar eclipse, (2 an intense heating of the lower stratosphere by 8 °C after nearly four hours from the maximum phase of the annular eclipse, and (3 drastic variations in the diurnal evolution of the tropical tropopause characteristics. The cooling effect is attributed to the radiative response of the atmosphere to the solar eclipse, where as heating is attributed to

  5. Temperature perturbations in the troposphere-stratosphere over Thumba (8.5 N, 76.9 E) during the solar eclipse 2009/2010

    Energy Technology Data Exchange (ETDEWEB)

    Subrahmanyam, K.V.; Ramkumar, G.; Kumar, K.K. [VSSC, ISRO, Trivandrum (IN). Space Physics Lab.] (and others)

    2011-07-01

    Measurements of atmospheric temperature profiles in the troposphere and lower stratosphere were made over Thumba Equatorial Rocket Launching Station (TERLS) (8.5 N, 76.9 E) during a partial solar eclipse (22 July 2009) and an annular solar eclipse (15 January 2010). It was observed that during the partial solar eclipse, the temperature decreased by 2-3 C in the vicinity of the tropopause and in the lower stratosphere the temperature increased by {proportional_to}2.6 C during the maximum phase of the partial solar eclipse. During the annular solar eclipse, a temperature reduction of {proportional_to}2 C was observed around the tropopause. This study also revealed a feature of delayed effect in the form of a very intense warming of {proportional_to}8 C at 18 km after about 4 h of the annular solar eclipse. The Cold-Point Tropopause (CPT) temperature increased slowly before the beginning of the eclipse (up to 10:00 IST) and during the maximum phase of the eclipse, the difference in CPT temperature and height was -3.5 C and {proportional_to}110 m, respectively, as that of the control day. After the four hours of the eclipse, the CPT height had decreased by {proportional_to}1.7 km and the CPT temperature increased by {proportional_to}4.6 C. This is for the first time that the diurnal variation of the tropopause has been reported during a solar eclipse day. The present study, thus, provided an opportunity to investigate the temperature perturbations in the troposphere and lower stratosphere during a partial and annular solar eclipse. The highlight of the present results are (1) cooling of the entire troposphere and lower stratosphere during the maximum phase of annular solar eclipse, (2) an intense heating of the lower stratosphere by 8 C after nearly four hours from the maximum phase of the annular eclipse, and (3) drastic variations in the diurnal evolution of the tropical tropopause characteristics. The cooling effect is attributed to the radiative response of the

  6. Impacts of the solar eclipse of 29 March 2006 on the surface ozone concentration, the solar ultraviolet radiation and the meteorological parameters at Athens, Greece

    Directory of Open Access Journals (Sweden)

    C. Tzanis

    2008-01-01

    Full Text Available In this study the variations in the surface ozone concentration, the solar ultraviolet radiation and the meteorological parameters at the ground before, during and after the total solar eclipse of 29 March 2006 have been examined. This analysis is based on the measurements performed at four stations located in the greater Athens basin in Greece. The experimental data demonstrated that the solar eclipse phenomenon affects the surface ozone concentration as well as the temperature, the relative humidity and the wind speed near the ground. The decrease in the surface ozone concentration that observed after the beginning of the eclipse event lasted almost two hours, probably due to the decreased efficiency of the photochemical ozone formation. The reduction of the solar ultraviolet radiation at 312 and 365 nm reached 97% and 93% respectively, while the air temperature dropped, the relative humidity increased and the wind speed decreased.

  7. Multifocal electroretinogram for assessing sun damage following the solar eclipse of 29 March 2006: multifocal electroretinography in solar maculopathy.

    Science.gov (United States)

    Arda, Hatice; Oner, Ayse; Mutlu, Sait; Köse, Ziya; Gumus, Koray; Karakucuk, Sarper; Mirza, Ertugrul

    2007-05-01

    To evaluate the clinical findings and multifocal electroretinography results of cases with solar maculopathy due to eclipse watching. Eight eyes of six patients (ages ranged 12-42) who presented to our clinic after the solar eclipse of 29 March 2006 were evaluated in the study. All patients underwent a full ophthalmologic examination and multifocal electroretinography (mfERG). Visual acuities at the initial examination were between 20/32 and 20/20; and at final examination between 20/25 and 20/20 respectively. Fundoscopic examination disclosed macular pigmentary changes in almost all patients. Fundus Fluorescein Angiography revealed a window defect in six eyes. The initial findings of the mfERG at the first visit showed a decrease in the P1 and N1 amplitudes of the central responses. The following mfERG recordings showed a recovery in central P1 and N1 amplitudes. Decrease in P1 and N1 amplitudes of central macular region can be detected by mfERG in patients with solar maculopathy. Follow-up mfERG test results may recover with the increase of visual acuity.

  8. The variation of the solar diameter and irradiance : eclipse observation of July, 11, 2010

    CERN Document Server

    Serge, Koutchmy; Jean-Yves, Prado; Philippe, Lamy; Patrick, Rocher

    2012-01-01

    The variation of the solar diameter is the subject of hot debates due to the possible effect on Earth climate and also due to different interpretations of long period solar variabilities, including the total solar irradiance. We shortly review the topic and show that rather long term variations, corresponding to a length well over a a solar magnetic cycle, are interesting to consider. The very recently launched mission "Picard" is entirely devoted to the topic but will just permit a short term evaluation. At the time of the last total solar eclipse of 11/07/2010, several experiments were prepared to precisely measure the transit time of the Moon related to the precise value of the solar diameter. Preliminary results coming from the use of a specially designed CNES photometer, put on different atolls of the French Polynesia, are presented. In addition the results of new experiments devoted to fast observations of flash spectra, including their precise chronodating, are illustrated and discussed. A new definiti...

  9. The effect of the total solar eclipse of 29 March 2006 on meteorological variables in Greece

    Directory of Open Access Journals (Sweden)

    D. Founda

    2007-11-01

    Full Text Available This paper examines the effect of the total solar eclipse of 29 March 2006 on meteorological variables across Greece. Integrated micrometeorological measurements were conducted at Kastelorizo, a small island within the path of totality, and other sites within the Greek domain, with various degrees of solar obscuration. The observations showed a dramatic reduction in the incoming global radiation and subsequent, pronounced changes in surface air temperature with the lowest temperature values occurring about 15 min after the full phase. The amplitude of the air temperature drop was not analogous to the obscuration percentage but was principally determined by the surrounding environment (mainly the sea influence, the background meteorological conditions and local cloudiness. Surface wind-speed decreased in most sites as a result of the cooling and stabilization of the atmospheric boundary layer. This perturbation provided a unique opportunity to apply a sensitivity analysis on the effect of the eclipse to the Weather Research and Forecast (WRF numerical mesoscale meteorological model. Strong anomalies, not associated with a dynamic response, were simulated over land especially in surface air temperature. The simulated temperature drop pattern was consistent with the observations.

  10. Evidence of gravity waves into the atmosphere during the March 2006 total solar eclipse

    Directory of Open Access Journals (Sweden)

    C. S. Zerefos

    2007-05-01

    Full Text Available This study aims at testing the hypothesis according to which the movement of the moon's shadow sweeping the ozone layer at supersonic speed during a solar eclipse creates gravity waves in the atmosphere. An experiment was conducted to study fluctuations of the ozone layer, the Ionosonde Total Electron Content (ITEC and the peak electron density height (hmF2 in the ionosphere, as well as at a number of other parameters before, during and after the total solar eclipse. We found the existence of dominant oscillations with periods ranging between 30–40 min in most of the parameters. Cross-spectrum analyses between total ozone and various atmospheric parameters resulted to statistically significant square coherences between the observed oscillations, while the respective phase spectra show that the perturbation originates in the stratosphere and reaches the various layers at speeds around 20 km min−1. Additional evidence supporting these findings was provided by the amplitude of the oscillations in the ionospheric electron density, which increased upwards from 160 to 220 km height.

  11. The effect of the total solar eclipse of 29 March 2006 on meteorological variables in Greece

    Directory of Open Access Journals (Sweden)

    D. Founda

    2007-07-01

    Full Text Available This paper examines the effect of the total solar eclipse of 29 March 2006 on meteorological variables across Greece. Integrated micrometeorological measurements were conducted at Kastelorizo, a small island within the path of totality, and other sites within the Greek domain, with various degrees of solar obscuration. The observations showed a dramatic reduction in the incoming global radiation and subsequent, pronounced changes in surface air temperature with the lowest temperature values occurring about 15 min after the full phase. The amplitude of the air temperature drop was not analogous to the obscuration percentage but was principally determined by the surrounding environment (mainly the sea influence, the background meteorological conditions and local cloudiness. Surface wind-speed decreased in most sites as a result of the cooling and stabilization of the atmospheric boundary layer. This perturbation provided a unique opportunity to apply a sensitivity analysis on the effect of the eclipse to the Weather Research and Forecast (WRF numerical mesoscale meteorological model. Strong anomalies, not associated with a dynamic response, were simulated over land especially in surface air temperature. The simulated temperature drop pattern was consistent with the observations.

  12. Early Evaluation of the Corona at the 2016 March 9 Total Solar Eclipse

    Science.gov (United States)

    Pasachoff, Jay M.; Seaton, Daniel B.; Sterling, Alphonse C.

    2016-05-01

    We observed the corona on 2016 March 9 with a variety of assets on the ground and in space. The umbra of the total eclipse swept across Indonesia and into the Pacific, with totality at our Indonesian observation sites lasting 2 min 45 s at Ternate in the Spice Islands (Malukus) and 2 min 10 at Belitung. We compare our ground-based results with the coronal configurations observed with PROBA2/SWAP and Hinode XRT. One of our scientific goals is to follow the coronal configuration over the solar-activity cycle, with the sunspot number now half its maximum of either its 2012 or 2014 peak. We are evaluating temporal changes by comparing eclipse observations made at several ground-based sites along the path, with the longest span being 75 min from Belitung to the Woleia atoll in mid-Pacific, 1:25 UTC to 2:40 UTC; we are evaluating whether the airborne observations made at 3:35 UTC on March 8 (across the International Dateline) are of suitable quality to provide further comparison at high spatial resolution. We also compare our images with the near-simultaneous coronal observations made with SOHO/LASCO, SDO/AIA, STEREO-A/SECCHI, and the Mauna Loa Solar Observatory's K-cor coronagraph. ACS received support for image analysis from the Hinode project.

  13. Coronal streamers revealed during solar eclipses: Seeing is not believing, and pictures can lie.

    Science.gov (United States)

    Woo, Richard

    2011-01-01

    For those fortunate enough to have personally witnessed and photographed the visible corona surrounding the Sun during a solar eclipse, pictures are usually a let down for not living up to the visual view. After 150 years of investigating the corona, we understand it more fully and now know this difference to be real. The difference stems from our inability to either see or image the true distribution of simultaneous brightness because of its large dynamic range (eg, Rodriguez, Woods, 2008 Digital Image Processing, Upper Saddle River: Pearson Prentice Hall). Brightness in the corona is unprecedented, as it falls by three orders of magnitude over a distance of only one solar radius from the Sun.

  14. Coronal Streamers Revealed during Solar Eclipses: Seeing is not Believing, and Pictures Can Lie

    Directory of Open Access Journals (Sweden)

    Richard Woo

    2011-08-01

    Full Text Available For those fortunate enough to have personally witnessed and photographed the visible corona surrounding the Sun during a solar eclipse, pictures are usually a let down for not living up to the visual view. After 150 years of investigating the corona, we understand it more fully and now know this difference to be real. The difference stems from our inability to either see or image the true distribution of simultaneous brightness because of its large dynamic range (eg, Rodriguez, Woods, 2008 Digital Image Processing, Upper Saddle River: Pearson Prentice Hall. Brightness in the corona is unprecedented, as it falls by three orders of magnitude over a distance of only one solar radius from the Sun.

  15. Attenuation of global ultraviolet and visible irradiance over Greece during the total solar eclipse of 29 March 2006

    Directory of Open Access Journals (Sweden)

    A. Kazantzidis

    2007-12-01

    Full Text Available The variability of ultraviolet and photosynthetically active radiation (PAR during the total solar eclipse of 29 March 2006 was examined in this study. The measurements from NILU-UV multichannel radiometers at 7 stations of the Greek UV Network were used, where the maximum eclipse percentage ranged from 73.1% to 94.8%. In addition, an extra instrument was established at a remote Greek island, Kastelorizo, which was within the Moon's umbral shadow. The reduction of irradiance at 305 and 312 nm relative to non-eclipse conditions at all sites was almost 1.5 times more than the corresponding decrease in the UVA and visible part of the spectrum and reached 98% for eclipse percentage equal to 94%. The availability of several instruments in close proximity to the path of the umbral shadow provided a challenging test for the models. The measured changes in UV and visible irradiance were compared with 1-D model calculations accounting for the limb darkening effect. The agreement between measurements and modeled values at all sites is within 3% for eclipse percentages of less than 30% and becomes worse as the eclipse progresses. The 1-D model reproduced the spectral effect of the eclipse in UVA and PAR wavelength regions within 3% for eclipse percentages up to 50%, but only the half of the observed change was captured as the eclipse progressed. At three sites, where the eclipse maximum was more than 94%, the measured irradiance at 305 nm for eclipse percentages of more than 85% decreased with slower rates than for longer wavelengths. As a result, the total ozone values, derived from the 305/320 nm ratios, apparently decreased significantly for high eclipse percentages. The effect is similar at all three sites, but the interpretation of this observation remains a challenge. Comparison results with 3-D model calculations shortly before, during and shortly after totality were performed for the first time and revealed an agreement with measurements

  16. Detection of short period intensity oscillations in the solar corona observed during the total solar eclipse of august 11, 1999

    Directory of Open Access Journals (Sweden)

    R. Rezaei

    2005-03-01

    Full Text Available   An experiment to search for short-period intensity oscillations in the solar corona was conducted during the total solar eclipse of August 11, 1999 in Esfahan, Iran. The intensity in the continuum, centered about 4700 Å and with a passband having a half-width of 190 Å, was recorded at a counting rate of 5 Hz using six low-noise Hamamatsu R647 photomultiplier tubes. We recorded intensity values from 6 different regions on the image of the solar corona from 1.2 R ° to 1.5 R ° . The power spectrum analysis of all channels, except for a channel that failed to receive any coronal light, shows excess power in the frequency range 0.02-0.2 Hz. The results of analyzing all channels demonstrate various waves with some degree of coherence and amplitudes from 0.3 to 0.7 percent of the mean coronal brightness. There are some similarities between waves in various channels and it may show that these waves exist in a large region of the corona, of the order of a few hundred thousand kilometers, much larger than the fiber optic diaphragms. The energy flux of each wave was calculated by assuming them as the slow or fast mode waves for the active and quiet regions of the solar corona. The energy flux of the fast mode waves in the active regions is comparable with the required energy flux for heating up the solar corona. The intensity oscillations observed in this experiment are similar to those detected during the 1995 and 1997 eclipses.

  17. Multi-instrument observations of the solar eclipse on 20 March 2015 and its effects on the ionosphere over Belgium and Europe

    Science.gov (United States)

    Stankov, Stanimir M.; Bergeot, Nicolas; Berghmans, David; Bolsée, David; Bruyninx, Carine; Chevalier, Jean-Marie; Clette, Frédéric; De Backer, Hugo; De Keyser, Johan; D'Huys, Elke; Dominique, Marie; Lemaire, Joseph F.; Magdalenić, Jasmina; Marqué, Christophe; Pereira, Nuno; Pierrard, Viviane; Sapundjiev, Danislav; Seaton, Daniel B.; Stegen, Koen; Van der Linden, Ronald; Verhulst, Tobias G. W.; West, Matthew J.

    2017-08-01

    A total solar eclipse occurred on 20 March 2015, with a totality path passing mostly above the North Atlantic Ocean, which resulted in a partial solar eclipse over Belgium and large parts of Europe. In anticipation of this event, a dedicated observational campaign was set up at the Belgian Solar-Terrestrial Centre of Excellence (STCE). The objective was to perform high-quality observations of the eclipse and the associated effects on the geospace environment by utilising the advanced space- and ground-based instrumentation available to the STCE in order to further our understanding of these effects, particularly on the ionosphere. The study highlights the crucial importance of taking into account the eclipse geometry when analysing the ionospheric behaviour during eclipses and interpreting the eclipse effects. A detailed review of the eclipse geometry proves that considering the actual obscuration level and solar zenith angle at ionospheric heights is much more important for the analysis than at the commonly referenced Earth's surface or at the plasmaspheric heights. The eclipse occurred during the recovery phase of a strong geomagnetic storm which certainly had an impact on (some of) the ionospheric characteristics and perhaps caused the omission of some "low-profile" effects. However, the analysis of the ionosonde measurements, carried out at unprecedented high rates during the eclipse, suggests the occurrence of travelling ionospheric disturbances (TIDs). Also, the high temporal and spatial resolution measurements proved very important in revealing and estimating some finer details of the delay in the ionospheric reaction and the ionospheric disturbances.

  18. Effects on surface atmospheric photo-oxidants over Greece during the total solar eclipse event of 29 March 2006

    Directory of Open Access Journals (Sweden)

    P. Zanis

    2007-08-01

    Full Text Available This study investigates the effects of the total solar eclipse of 29 March 2006 on surface air-quality levels over Greece based on observations at a number of sites in conjunction with chemical box modelling and 3-D air-quality modelling. Emphasis is given on surface ozone and other photooxidants at four Greek sites Kastelorizo, Finokalia (Crete, Pallini (Athens and Thessaloniki, which are located at gradually increasing distances from the path of the eclipse totality and are characterized by different air pollution levels. The eclipse offered the opportunity to test our understanding of air pollution build-up and the response of the gas-phase chemistry of photo-oxidants during a photolytical perturbation using both a photochemical box model and a regional air-quality offline model based on the modeling system WRF/CAMx. At the relatively unpolluted sites of Kastelorizo and Finokalia no clear impact of the solar eclipse on surface O3, NO2 and NO concentrations can be deduced from the observations and model simulations as the calculated changes in net ozone production rates between eclipse and non eclipse conditions are rather small compared to the ozone variability and hence the solar eclipse effects on ozone can be easily masked by transport. At the polluted sites of Thessaloniki and Pallini, the solar eclipse effects on O3, NO2 and NO concentrations are clearly revealed from both the measurements and 3-D air-quality modeling with the net effect being a decrease in O3 and NO and an increase in NO2 as NO2 formed from the reaction of O3 with NO while at the same time NO2 is not efficiently photolysed. It is evident from the 3-D air quality modeling over Greece that the maximum effects of the eclipse on O3, NO2 and NO are reflected at the large urban agglomerations of Athens, and Thessaloniki where the maximum of the emissions

  19. Effects on surface atmospheric photo-oxidants over Greece during the total solar eclipse event of 29 March 2006

    Directory of Open Access Journals (Sweden)

    P. Zanis

    2007-12-01

    Full Text Available This study investigates the effects of the total solar eclipse of 29 March 2006 on surface air-quality levels over Greece based on observations at a number of sites in conjunction with chemical box modelling and 3-D air-quality modelling. Emphasis is given on surface ozone and other photooxidants at four Greek sites Kastelorizo, Finokalia (Crete, Pallini (Athens and Thessaloniki, which are located at gradually increasing distances from the path of the eclipse totality and are characterized by different air pollution levels. The eclipse offered the opportunity to test our understanding of air pollution build-up and the response of the gas-phase chemistry of photo-oxidants during a photolytical perturbation using both a photochemical box model and a regional air-quality offline model based on the modeling system WRF/CAMx. At the relatively unpolluted sites of Kastelorizo and Finokalia no clear signal of the solar eclipse on surface O3, NO2 and NO concentrations can be deduced from the observations while there is no correlation of observed O3, NO2 and NO with observed global radiation. The box and regional model simulations for the two relatively unpolluted sites indicate that the calculated changes in net ozone production rates between eclipse and non eclipse conditions are rather small compared to the observed short-term ozone variability. Furthermore the simulated ozone lifetime is in the range of a few days at these sites and hence the solar eclipse effects on ozone can be easily masked by local and regional transport. At the polluted sites of Thessaloniki and Pallini, the solar eclipse effects on O3, NO2 and NO concentrations are revealed from both the measurements and modeling with the net effect being a decrease in O3 and NO and an increase in NO2 as NO2 formed from the reaction of O3 with NO while at the same time NO2 is

  20. Modeling of the lower ionospheric response and VLF signal modulation during a total solar eclipse using ionospheric chemistry and LWPC

    Science.gov (United States)

    Chakraborty, Suman; Palit, Sourav; Ray, Suman; Chakrabarti, Sandip K.

    2016-02-01

    The variation in the solar Extreme Ultraviolet (EUV) radiation flux by any measure is the most dominant natural source to produce perturbations or modulations in the ionospheric chemical and plasma properties. A solar eclipse, though a very rare phenomenon, is similarly bound to produce a significant short time effect on the local ionospheric properties. The influence of the ionizing solar flux reduction during a solar eclipse on the lower ionosphere or, more precisely, the D-region, can be studied with the observation of Very Low Frequency (VLF) radio wave signal modulation. The interpretation of such an effect on VLF signals requires a knowledge of the D-region ion chemistry, which is not well studied till date. Dominant parameters which govern the ion chemistry, such as the recombination coefficients, are poorly known. The occurrence of events such as a solar eclipse provides us with an excellent opportunity to investigate the accuracy of our knowledge of the chemical condition in this part of Earth's atmosphere and the properties which control the ionospheric stability under such disturbances. In this paper, using existing knowledge of the lower ionospheric chemical and physical properties we carry out an interpretation of the effects obtained during the total solar eclipse of 22 of July 2009 on the VLF signal. Data obtained from a week long campaign conducted by the Indian Centre for Space Physics (ICSP) over the Indian subcontinent has been used for this purpose. Both positive and negative amplitude changes during the eclipse were observed along various receiver locations. In this paper, data for a propagation path between a Indian Navy VLF transmitter named VTX3 and a pair of receivers in India are used. We start from the observed solar flux during the eclipse and calculate the ionization during the whole time span over most of the influenced region in a range of height. We incorporate a D-region ion-chemistry model to find the equilibrium ion density over

  1. Hybrid emitter all back contact solar cell

    Science.gov (United States)

    Loscutoff, Paul; Rim, Seung

    2016-04-12

    An all back contact solar cell has a hybrid emitter design. The solar cell has a thin dielectric layer formed on a backside surface of a single crystalline silicon substrate. One emitter of the solar cell is made of doped polycrystalline silicon that is formed on the thin dielectric layer. The other emitter of the solar cell is formed in the single crystalline silicon substrate and is made of doped single crystalline silicon. The solar cell includes contact holes that allow metal contacts to connect to corresponding emitters.

  2. A potential lag between the open solar magnetic source flux and solar EUV and X-ray emissions as measured by the Earth's ionosphere during total solar eclipses

    Directory of Open Access Journals (Sweden)

    C. J. Davis

    2009-06-01

    Full Text Available Measurements of the ionospheric E-region during total solar eclipses have been used to provide information about the evolution of the solar magnetic field and EUV and X-ray emissions from the solar corona and chromosphere. By measuring levels of ionisation during an eclipse and comparing these measurements with an estimate of the unperturbed ionisation levels (such as those made during a control day, where available it is possible to estimate the percentage of ionising radiation being emitted by the solar corona and chromosphere. Previously unpublished data from the two eclipses presented here are particularly valuable as they provide information that supplements the data published to date. The eclipse of 23 October 1976 over Australia provides information in a data gap that would otherwise have spanned the years 1966 to 1991. The eclipse of 4 December 2002 over Southern Africa is important as it extends the published sequence of measurements. Comparing measurements from eclipses between 1932 and 2002 with the solar magnetic source flux reveals that changes in the solar EUV and X-ray flux lag the open source flux measurements by approximately 1.5 years. We suggest that this unexpected result comes about from changes to the relative size of the limb corona between eclipses, with the lag representing the time taken to populate the coronal field with plasma hot enough to emit the EUV and X-rays ionising our atmosphere.

  3. Total solar eclipse of 16 February 1980 and the vertical profiles of atmospheric parameters in the lowest 200M

    Digital Repository Service at National Institute of Oceanography (India)

    RameshBabu, V.; Sastry, J.S.

    Vertical profiles of air temperature, wind and humidity at Raichur (16 degrees 12'N and 77 degrees 21'E) in the lowest 200m of the atmosphere are presented for the period 15-18 February 1980. The effect of the total solar eclipse, on 16 February...

  4. Effects of March 20, 2015, partial (~50% solar eclipse on meteorological parameters in the urban area of Naples (Italy

    Directory of Open Access Journals (Sweden)

    Nicola Scafetta

    2016-02-01

    Full Text Available During the partial (~50% solar eclipse occurred on March 20, 2015, morning, various meteorological parameters were monitored to study their evolution above the urban area of Naples, central Italy. The experimental conditions were optimal because of the clear sky situation all over Italy, and in Naples in particular. The eclipse last about 2 hours between 9:25:06 (UT+1, local Italian time and 11:43:09 (local Italian time, UT+1. From the observation site, the incoming solar radiation diminished by about 50% at the eclipse peak at 10:32:18 (local Italian time, UT+1, as expected. On the contrary, the UV radiation diminished significantly less, about 25%. This frequency response was likely due to Rayleigh scattering. It suggests that about 50% of the UV radiation reaching the surface was direct light and 50% scattered light. During the eclipse, the urban surface temperature and humidity values stayed almost constant instead of increasing and decreasing, respectively, as predicted by their daily cycle. This result was used to estimate that the average emissivity of the city of Naples is about f = 0.86. The wind speed decreased significantly during the event while the atmospheric pressure stayed constant to decrease only after the eclipse. Finally, we propose a simple empirical method to approximately estimate the cooling effect of an eclipse, which meteorologists could use to correct the temperature model forecast that normally ignores the occurrence of an eclipse. Consistency of these results with the literature and its importance is briefly discussed.

  5. Wind-solar Hybrid Power System

    OpenAIRE

    Jin, Fei

    2014-01-01

    In the development and utilization of new energy sources, the solar energy and wind energy are paid more attention by various countries, and have become a new field of energy development and utilization of the highest level, the most mature technology, the most widely used and commercial development conditions for new energy. But both the traditional wind power system and solar power system have the characteristic of energy instability. Therefore, wind-solar hybrid power system was proposed i...

  6. On the variability of near-surface screen temperature anomalies in the 20 March 2015 solar eclipse.

    Science.gov (United States)

    Clark, Matthew R

    2016-09-28

    Near-surface air temperature (NSAT) anomalies during the 20 March 2015 solar eclipse are investigated at 266 UK sites, using operational data. The high density of observing sites, together with the wide range of ambient meteorological conditions, provided an unprecedented opportunity for analysis of the spatial variability of NSAT anomalies under relatively uniform eclipse conditions. Anomalies ranged from -0.03°C to -4.23°C (median -1.02°C). The maximum (negative) anomaly lagged the maximum obscuration by 15 min on average. Cloud cover impacted strongly on NSAT anomalies, with larger anomalies in clear-sky situations (peclipse, the topographical influences on NSAT anomalies were apparently dominated by variations in residual nocturnal inversion strength, as suggested by significant correlations between post-sunrise temperature and NSAT anomaly at clear-sky sites (larger negative anomalies with lower post-sunrise temperatures). The largest NSAT anomaly occurred at a coastal site where flow transitioned from onshore to offshore during the eclipse, in a situation with large coastal temperature gradients associated with antecedent nocturnal cooling.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  7. Transfer of telemedical support to Cornwall from a national telemedicine network during a solar eclipse.

    Science.gov (United States)

    Wootton, R; McKelvey, A; McNicholl, B; Loane, M; Hore, D; Howarth, P; Tachakra, S; Rocke, L; Martin, J; Page, G; Ferguson, J; Chambers, D; Hassan, H

    2000-01-01

    During late 1998 and early 1999, planning officers in Cornwall predicted a huge increase in summer visitors to the county to observe the August solar eclipse. There was the possibility that a mass gathering in Cornwall could overload existing arrangements for handling accident and emergency patients. We therefore set up a telemedicine system to support the county's minor injury units (MIUs) from hospitals throughout the UK. Six main hospital accident and emergency departments outside Cornwall with existing links to their own MIUs were twinned with 10 of the 11 MIUs in Cornwall before the expected date of the gathering. The network was live for nine days, starting four days before the eclipse, and 2045 patients were seen in the 10 MIUs. There were 93 telemedicine calls from the 10 MIUs, involving 91 patients. Overall, 4.6% of the patients required a telemedicine consultation. Fifty-seven calls were made during working hours. Thirty-four patients were referred for further management, of whom 18 were referred on the same day. The transfer of telemedical support to a national network was successful.

  8. A study of integrated learning and the value of science in remote education: using the Internet to relay the total solar eclipse of 2001 June 11 in Africa

    Science.gov (United States)

    Takahashi, N.; Agata, H.; Maeda, K.; Okyudo, M..; Yamazaki, Y.

    A total solar eclipse was observed on 2001 June 21 in Angola, Zambia, and Zimbabwe in Africa. For the purpose of promotion of science education using a solar eclipse as an educational project, the whole image and an enlarged image of the Sun, that showed the process of an eclipse and how things went in the observation area, were broadcast to the world through the Internet (Live Eclipse). Such images were distributed to four primary schools in Hiroshima and the Science and Technology Museum in Tokyo to give a remote lecture through computers. To find the effectiveness of the lecture, the learning effect on the participating children was examined two times before and after the remote lecture on the solar eclipse.

  9. Terrestrial atmospheric responses on Svalbard to the 20 March 2015 Arctic total solar eclipse under extreme conditions.

    Science.gov (United States)

    Pasachoff, J M; Peñaloza-Murillo, M A; Carter, A L; Roman, M T

    2016-09-28

    This article reports on the near-surface atmospheric response at the High Arctic site of Svalbard, latitude 78° N, as a result of abrupt changes in solar insolation during the 20 March 2015 equinox total solar eclipse and notifies the atmospheric science community of the availability of a rare dataset. Svalbard was central in the path of totality, and had completely clear skies. Measurements of shaded air temperature and atmospheric pressure show only weak, if any, responses to the reduced insolation. A minimum in the air temperature at 1.5 m above the ground occurred starting 2 min following the end of totality, though this drop was only slightly beyond the observed variability for the midday period. Eclipse-produced variations in surface pressure, if present, were less than 0.3 hPa.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  10. Zenith skylight intensity and color during the total solar eclipse of 20 July 1963.

    Science.gov (United States)

    Sharp, W E; Lloyd, J W; Silverman, S M

    1966-05-01

    The zenith skylight intensity was measured, with a resolution of 10 A, over the wavelength range from 5200 A to 6400 A during a total solar eclipse at Hermon, Maine. The intensity was found to change by about two orders of magnitude in the 2-min period before totality and reached a minimum during totality of 19.5 kR/A at 5200 A. The spectral distribution remained that of the day sky until the sun was more than 99.8% obscured. During totality, the shorter wavelengths were enhanced, indicating a shift to the blue in sky color. Comparisons with an independent measurement from an aircraft show that the intensity scale height of the secondary scattered component, predominating at totality, is significantly less than that of the day sky. The measurements are compared with the day and twilight sky.

  11. Teaching Introductory Astronomy "Open and Out" & Looking Forward to the 2017 Solar Eclipse

    Science.gov (United States)

    Chu, I.-Wen Mike; Cronkhite, Jeff

    2016-01-01

    We present a new effort on teaching introductory astronomy addressing the specific challenges facing small colleges including limited resources, changing generational behavior and new technological trends. The approach adopts open source solutions into the developmental learning materials aiming for standardization and wide-scale applicability. In addition we utilize events and resources outside classroom into the learning. Among examples of the development are laboratory exercises based on the planetarium software Stellarium and remediation exercises using Khan Academy instructional videos. As the eventual goal is to move toward greater autonomy the cycles of improvement necessarily require student feedback in an entirely different instructional style based on egalitarian dialogues. We highlight a laboratory exercise on Earth-Moon distance estimation using parallax of the upcoming 2017 solar eclipse to illustrate the "open and out" philosophy. Achievements, limitations and some diagnostics of the current effort are also presented.

  12. Space Based Observations of Coronal Cavities in Conjunction with the Total Solar Eclipse of July 2010

    Science.gov (United States)

    Kucera, T. A.; Berger, T. E.; Druckmuller, M.; Dietzel, M.; Gibson, S. E.; Habbal, S. R.; Morgan, H.; Reeves, K. K.; Schmit, D. J.; Seaton, D. B.

    2010-01-01

    In conjunction with the total solar eclipse on July 11, 2010 we coordinated a campaign between ground and space based observations. Our specific goal was to augment the ground based measurement of corona) prominence cavity temperatures made using iron lines in the IR (Habbal et al. 2010 ApJ 719 1362) with measurements performed by space based instruments. Included in the campaign were Hinode/EIS, XRT and SOT, PROBA2/SWAP, SDO/AIA, SOHO/CDS and STEREO/SECCHI/EUVI, in addition to the ground based IR measurements. We plan to use a combination of line ratio and forward modeling techniques to investigate the density and temperature structure of the cavities at that time.

  13. Multiwavelength Lidar Observation of the Atmospheric Response to the 20th March 2015 Partial Solar Eclipse in Rome Tor Vergata: Preliminary Results.

    Directory of Open Access Journals (Sweden)

    Liberti Gian Luigi

    2016-01-01

    Full Text Available This study reports some preliminary analyses of multichannel lidar measurements taken in Rome Tor Vergata (Italy during the 20th March 2015 partial solar eclipse. The objective is assessing the capability of the instrument to document the effect of the eclipse in the lower troposphere, with a particular emphasis on the information content at relatively small temporal and spatial scales.

  14. Multiwavelength Lidar Observation of the Atmospheric Response to the 20th March 2015 Partial Solar Eclipse in Rome Tor Vergata: Preliminary Results.

    Science.gov (United States)

    Liberti, Gian Luigi; Dionisi, Davide; Federico, Stefano; Congeduti, Fernando

    2016-06-01

    This study reports some preliminary analyses of multichannel lidar measurements taken in Rome Tor Vergata (Italy) during the 20th March 2015 partial solar eclipse. The objective is assessing the capability of the instrument to document the effect of the eclipse in the lower troposphere, with a particular emphasis on the information content at relatively small temporal and spatial scales.

  15. Absolute dimensions of solar-type eclipsing binaries III. EW orionis

    DEFF Research Database (Denmark)

    Clausen, Jens Viggo; Bruntt, H.; Olsen, E. H.

    2010-01-01

    stars: evolution / stars: fundamental parameters / stars: abundances / binaries: eclipsing / techniques: photometric / techniques: spectroscopic Udgivelsesdato: 23 Feb.......stars: evolution / stars: fundamental parameters / stars: abundances / binaries: eclipsing / techniques: photometric / techniques: spectroscopic Udgivelsesdato: 23 Feb....

  16. Simulation of hybrid solar power plants

    Science.gov (United States)

    Dieckmann, Simon; Dersch, Jürgen

    2017-06-01

    Hybrid solar power plants have the potential to combine advantages of two different technologies at the cost of increased complexity. The present paper shows the potential of the software greenius for the techno-economic evaluation of hybrid solar power plants and discusses two exemplary scenarios. Depreciated Concentrated Solar Power (CSP) plants based on trough technology can be retrofitted with solar towers in order to reach higher steam cycle temperatures and hence efficiencies. Compared to a newly built tower plant the hybridization of a depreciated trough plant causes about 30% lower LCOE reaching 104 /MWh. The second hybrid scenario combines cost-efficient photovoltaics with dispatchable CSP technology. This hybrid plant offers very high capacity factors up to 69% based on 100% load from 8am to 11pm. The LCOE of the hybrid plant are only slightly lower (174 vs. 186 /MWh) compared to the pure CSP plant because the capital expenditure for thermal storage and power block remains the same while the electricity output is much lower.

  17. Ionospheric response to the partial solar eclipse of March 29, 2006, according to the observations at Nizhni Novgorod and Murmansk

    Science.gov (United States)

    Belikovich, V. V.; Vyakhirev, V. D.; Kalinina, E. E.; Tereshchenko, V. D.; Chernyakov, S. M.; Tereshchenko, V. A.

    2008-02-01

    The results of observations of the solar eclipse ionospheric effects on March 29, 2006, are presented. The observations were conducted using the partial reflection method near Nizhni Novgorod and the vertical sounding method at the automatic ionospheric station near Murmansk. It has been obtained that the electron density at altitudes of 77 and 91 km decreases by a factor of more than 4; in this case the response of the ionosphere at an altitude of 91 km lags behind the eclipse maximum phase on the Earth by approximately 20 min. It has been established that the eclipse in the E and F1 regions of the polar ionosphere causes a change in the electron density by 15-20%. The delay time of this effect varies from 12 to 24 min depending on the altitude. It has been registered that the reflection virtual altitude at altitudes of the ionospheric F region increases in Murmansk and Nizhni Novgorod.

  18. Effects of total solar eclipse on the behavioural and metabolic activities of tropical intertidal animals

    Digital Repository Service at National Institute of Oceanography (India)

    Parulekar, A.H.; Ansari, Z.A.; Verlecar, X.N.; Harkantra, S.N.

    the pre-eclipse, eclipse and post-eclipse period, were carried out in the natural environment of Dias beach, Goa (Lat. 15 degrees 25'N; Long. 73 degrees 45'E). Environmental factors considered are tidal amplitude, atmospheric temperature and the sand...

  19. Prominence measurement of total solar eclipse: March 9th 2016, Ternate, Indonesia

    Science.gov (United States)

    Naufal, Luthfi; Abdan Malikul Mulki, Fargiza; Fatima, Siti; Widyanita; Zahirah, Saffanah; Dimas Satrya, Christoforus; Herdiwijaya, Dhani

    2016-11-01

    Prominence is a hot gas that consists of electrically charged particles, which is propelled outward Solar surface. It can happen when the activity of sunspot rising up. Ground- based observation of prominence is rather difficult due to the brightness of the Sun, which it needs appropriate method. During total solar eclipse (TSE), prominence is easier to observe. In Ternate, Maluku islands (0°4632.0"N 127°2305.7"E), we observed solar prominence in visual and infrared spectra performed by using regular-DSLR camera for visual wavelength and modified-DSLR (IR-cut filter removal) for infrared wavelength, respectively. Next, we calculated the length of prominence from TSE images, and found that the real minimum length of prominence in red is 1.05 times longer than green and blue ones. And, the real maximum length of prominence is 1.08 times longer than blue and 1.04 times longer than green. The intensity of red is brighter 1.37 times to green and 1.23 times to blue. The causes of the results due to the different temperatures of the prominences and the radiation from H-alpha emission. We succeeded to observe directly the prominence with simple cameras and measured its length and brightness.

  20. Center-to-Limb Variation of Solar Granulation from Partial Eclipse Observations

    Science.gov (United States)

    Sánchez Cuberes, M.; Bonet, J. A.; Vázquez, M.; Wittmann, A. D.

    2000-08-01

    We have measured the center-to-limb variation (CLV) of parameters describing geometric and photometric statistical properties of the solar granulation at 6708 Å. This work is based on an excellent series of white-light images obtained with the Swedish Vacuum Solar Telescope at Roque de los Muchachos Observatory, La Palma, during the partial solar eclipse of 1994 May 10. The lunar limb profile, which is visible in each frame, was used as a calibration tool for estimating the point-spread function of the combined optical system formed by the atmosphere and the telescope. Before restoration, noise was removed from the images by a novel application of the so-called optimum filter for two-dimensional objects. The latter was optimized in terms of rms error and was constructed from very precise smoothed models of the specific power spectrum of the granulation at each position on the solar disk. The determination of the positions on the solar disk was achieved with high accuracy by matching the position of the Moon's limb in our images to a numerical simulation of the eclipse geometry. The CLV curve of the ΔIrms granular contrast shows one of the steepest gradients among those reported in the literature and quite a high value (9.6%) at the disk center considering that our working wavelength is in the far-red range of the solar spectrum. The elliptical shape of the restored power spectra with ellipticities equal to those expected just from foreshortening proves that radiative transfer effects do not alter the isotropy of the horizontal intensity pattern of the solar granulation, at least up to μ=0.4. The mean wavenumber, k, derived from the two-dimensional power spectra azimuthally integrated along the ellipses amounts to a value of 6.15 Mm-1 at the center of the solar disk and then shows a decrease toward the limb. Apart from the power spectra analysis, a direct statistical study of the granulation size and brightness, based on the image segmentation for defining

  1. Attenuation of global ultraviolet and visible irradiance over Greece during the total solar eclipse of 29 March 2006

    Directory of Open Access Journals (Sweden)

    A. Kazantzidis

    2007-09-01

    Full Text Available The variability of ultraviolet and photosynthetically active radiation during the total solar eclipse of 29 March 2006 was examined in this study. The measurements from NILU-UV multichannel actinometers at 7 stations of the Greek UV Network were used, where the maximum eclipse percentage ranged from 73.1% to 94.8%. In addition, an extra instrument was established at a remote Greek island, Kastelorizo, which was within the Moon's umbral shadow. The measured changes in UV and visible irradiance were compared with 1-D model calculations (accounting for the limb darkening effect and differences up 30% were observed for the lower UV wavelengths at high eclipse percentages. The spectral ratios between wavelengths was generally reproduced by the 1-D model, expect for 305 nm, where the irradiance at eclipse percentages of more than 85% decreased with slower rates than for longer wavelengths. As a result, the total ozone, derived from the 305/320 nm ratio, apparently decreased significantly for high eclipse percentages. Comparison results with 3-D model calculations approaching and during totality revealed an agreement with measurements in the UV-A region.

  2. 2nd Joint Solar Dynamics Project data summary: Solar magnetic field, chromospheric and coronal observations near the time of the 11 June 1983 solar eclipse

    Science.gov (United States)

    Sime, D. G.; Fisher, R. R.; Garcia, C.; Najita, J. R.; Rock, K. A.; Seagraves, P. H.; Yasukawa, E.; McCabe, M. K.; Mickey, D. L.

    1983-07-01

    A comprehensive set of observations of the solar photosphere, chromosphere and corona is presented for one week on either side of the 11 June 1983 total solar eclipse. These observations, made at the Mauna Loa Solar Observatory and at the University of Hawaii's Mees Solar Observatory on Haleakala, include H images of the disk and the limb, off-band H sunspot and Ca-II K-line images, together with observations of the white light corona. Photospheric longitudinal magnetic field estimates made from the Fe line at 6302.5 by the Mees observatory Stokes photopolarimeter are included. The data are presented as daily observations. In the case of the k-coronal observations and the magnetic field data, synoptic maps were constructed for this interval.

  3. Joint solar dynamics project data summary (2nd): solar magnetic field, chromospheric and coronal observations near the time of the 11 June 1983 solar eclipse. Technical note

    Energy Technology Data Exchange (ETDEWEB)

    Sime, D.G.; Fisher, R.R.; Garcia, C.J.; Najita, J.R.; Rock, K.A.

    1983-07-01

    A comprehensive set of observations of the solar photosphere, chromosphere and corona is presented for one week on either side of the 11 June 1983 total solar eclipse. These observations, made at the Mauna Loa Solar Observatory and at the University of Hawaii's Mees Solar Observatory on Haleakala, include H images of the disk and the limb, off-band H sunspot and Ca-II K-line images, together with observations of the white light corona. Also included are photospheric longitudinal magnetic field estimates made from the Fe line at 6302.5, by the Mees observatory Stokes photo-polarimeter. The data are presented as daily observations. In the case of the k-coronal observations and the magnetic field data, synoptic maps have been constructed for this interval.

  4. Hybrid solar cells : Perovskites under the Sun

    NARCIS (Netherlands)

    Loi, Maria Antonietta; Hummelen, Jan C.

    2013-01-01

    Mixed-halide organic–inorganic hybrid perovskites are reported to display electron–hole diffusion lengths over 1 μm. This observation provides important insight into the charge-carrier dynamics of this class of semiconductors and increases the expectations for highly efficient and cheap solar cells.

  5. Switching the light off: A break in photosynthesis and sap flow of forest trees under total solar eclipse

    Directory of Open Access Journals (Sweden)

    Karl-Heinz Häberle

    2001-05-01

    Full Text Available In mature trees of Picea abies, Fagus sylvatica and Quercus robur, photosynthesis and transpiration were assessed in response to the total solar eclipse that occurred in Central Europe during the late morning hours of August 11, 1999, a day with changing cloudiness. Measurements were conducted at three forest sites located in the totality zone and the 99% area of the eclipse within a radius of about 100 km around the city of Munich (southern Germany. The eclipse lasting 164 minutes lowered the photosynthetic photon flux density (PPFD to about 1 μmol m-2 s-1 during the 2-minute totality period, when the sky was clear. During totality, photosynthesis was reduced to an extent that allowed CO2 release to dominate the gas exchange of leaves. Effects on transpiration were less pronounced as the totality was apparently too short to induce distinct stomatal closure in response to low PPFD. Transpiration was strongly reduced, however, by increased air humidity and wet leaf surfaces during sporadic rain showers which preceded or succeeded the eclipse during the same day, whereas low PPFD through intermittent cloudiness during rain only moderately reduced photosynthesis. Although transpiration was lowered to a minor extent only by the eclipse, the latter affected the water transport through the whole tree, as reflected in a decline in the sap flow rate through the basal stem part with a time delay depending on the species. Nevertheless, trees responded in a synchronous way, regardless of the site, species or the percent degree of the eclipse.

  6. The solar interface from the photosphere to the chromosphere and corona : contribution of eclipses and EUV filtergrams

    CERN Document Server

    Bazin, Cyrille

    2013-01-01

    Eclipses are very favourable for the photosphere- chromosphere and corona interface observation as the occultation takes place in space, free of parasitic light coming from the occulting disk (the Moon). Independently, EUV filtergrams of the limb region obtained in space were analyzed using one dimensional hydrostatic VAL models but this method ignores the ubiquitous magnetic field emergence phenomenon associated with the chromospheric network. A jump of temperature from 0.01 to 1 MK is observed near the 2 Mm heights and higher, further producing a permanent solar wind flow. The heating processes responsible for this temperature jump and for the flow are not yet fully understood. In this thesis, we reconsider these problems with new high cadence CCD flash spectra, white light (W-L) eclipse images and new EUV images obtained with space-borne instruments. We illustrate the mechanisms of low First Ionisation Potential (FIP) emission lines present in the low layers of the solar atmosphere, and nearby prominences....

  7. New Techniques Used in Modeling the 2017 Total Solar Eclipse: Energizing and Heating the Large-Scale Corona

    Science.gov (United States)

    Downs, Cooper; Mikic, Zoran; Linker, Jon A.; Caplan, Ronald M.; Lionello, Roberto; Torok, Tibor; Titov, Viacheslav; Riley, Pete; Mackay, Duncan; Upton, Lisa

    2017-08-01

    Over the past two decades, our group has used a magnetohydrodynamic (MHD) model of the corona to predict the appearance of total solar eclipses. In this presentation we detail recent innovations and new techniques applied to our prediction model for the August 21, 2017 total solar eclipse. First, we have developed a method for capturing the large-scale energized fields typical of the corona, namely the sheared/twisted fields built up through long-term processes of differential rotation and flux-emergence/cancellation. Using inferences of the location and chirality of filament channels (deduced from a magnetofrictional model driven by the evolving photospheric field produced by the Advective Flux Transport model), we tailor a customized boundary electric field profile that will emerge shear along the desired portions of polarity inversion lines (PILs) and cancel flux to create long twisted flux systems low in the corona. This method has the potential to improve the morphological shape of streamers in the low solar corona. Second, we apply, for the first time in our eclipse prediction simulations, a new wave-turbulence-dissipation (WTD) based model for coronal heating. This model has substantially fewer free parameters than previous empirical heating models, but is inherently sensitive to the 3D geometry and connectivity of the coronal field---a key property for modeling/predicting the thermal-magnetic structure of the solar corona. Overall, we will examine the effect of these considerations on white-light and EUV observables from the simulations, and present them in the context of our final 2017 eclipse prediction model.Research supported by NASA's Heliophysics Supporting Research and Living With a Star Programs.

  8. Response of the equatorial ionosphere to the total solar eclipse of 22 July 2009 and annular eclipse of 15 January 2010 as observed from a network of stations situated in the Indian longitude sector

    Directory of Open Access Journals (Sweden)

    A. Paul

    2011-10-01

    Full Text Available Dual-frequency GPS TEC monitors have been used to study the response of the ionosphere to the solar eclipses of 22 July 2009 and 15 January 2010. The receivers were located at three stations, Calcutta, Kharagpur and Baharampore which are situated outside the umbra zone in the Indian longitude sector with each baseline being ~200 km. Effects of obscuration of the solar disc were noted in the ambient TEC recorded at the three stations. A series of depletions in TEC along the track of a GPS satellite and associated wave-like structures were identified on some GPS links during both the eclipses.

  9. KIC 3858884: a hybrid {\\delta} Sct pulsator in a highly eccentric eclipsing binary

    CERN Document Server

    Maceroni, C; da Silva, R; Montalbán, J; Lee, C -U; Ak, H; Deshpande, R; Yakut, K; Debosscher, J; Guo, Z; Kim, S -L; Lee, J W; Southworth, J

    2014-01-01

    The analysis of eclipsing binaries containing non-radial pulsators allows: i) to combine two different and independent sources of information on the internal structure and evolutionary status of the components, and ii) to study the effects of tidal forces on pulsations. KIC 3858884 is a bright Kepler target whose light curve shows deep eclipses, complex pulsation patterns with pulsation frequencies typical of {\\delta} Sct, and a highly eccentric orbit. We present the result of the analysis of Kepler photometry and of high resolution phaseresolved spectroscopy. Spectroscopy yielded both the radial velocity curves and, after spectral disentangling, the primary component effective temperature and metallicity, and line-of-sight projected rotational velocities. The Kepler light curve was analyzed with an iterative procedure devised to disentangle eclipses from pulsations which takes into account the visibility of the pulsating star during eclipses. The search for the best set of binary parameters was performed com...

  10. Topside ionospheric effects of the annular solar eclipse of 15th January 2010 as observed by DEMETER satellite

    Science.gov (United States)

    Maji, Surya K.; Chakrabarti, Sandip K.; Sanki, Dipak; Pal, Sujay

    2017-06-01

    We present effects of the annular solar eclipse of 15th January 2010 on the topside ionosphere using the DEMETER satellite data. Measurements of the electron-ion density and electron temperature by the ISL (Instrument Sonde de Langmuir) and IAP (Instrument Analyseur de Plasma) instruments on board the DEMETER satellite during the eclipse time over the low latitude (±40) Indian ocean area are presented. We found the peak decrease in electron density to be about 35% and the peak decrease in ion density to be about 40% from the reference orbits at the altitude of the satellite (∼660 km). Electron and ion temperatures were found to have decreased by 200-300 K at the same altitude. Instead of simple decrease as in ion density, electron temperature showed a complex wave-like oscillation as the solar eclipse progressed. Electron density decreased to a minimum value before the maximum obscuration and starts to increase before passing through another minimum at the time of maximum obscuration. Both the minima are located at the ±10° geomagnetic latitude. Variations of electron and ion densities were found to follow the average solar illumination experienced by the satellite and its conjugate points at satellite altitude, while the electron temperature showed no such correlation.

  11. Zenith sky brightness and celestial objects visibility during total solar eclipse on March 9, 2016 at Terentang Beach Bangka Island

    Science.gov (United States)

    Wijaya, A. F. C.; Asmoro, C. P.; Rochman, A. A.; Ramalis, T. R.; Utama, J. A.; Ardi, N. D.; Amsor; Nugraha, M. G.; Saepuzaman, D.; Sutiadi, A.; Nurfiani, D.

    2016-11-01

    This paper endeavor to describe sky brightness measurements which was carried out by a team of total solar eclipse observers (TOGEMA) on 9th March 2016. The observations took place at Tarentang Beach, Bangka Island and it utilized the SQM-LU instrument (Sky Quality Meter- USB Connector) with 1 second time interval data. During total phase that lasted about 1 minute 52 seconds, the instrument recorded the brightness of the sky of 12.88 mag/["]2 as the dimmest value. This value is approximately 500 times brighter than the dimmest night sky conditions at the same location, obtained on the previous observation. It was found that the brightest sky that could be measured by SQM-LU during Total Solar Eclipse (TSE) 2016 was 5.91 mag/["]2. The activity with digital camera also captured the appearance of Venus and Mercury. The appearance of Venus (-3.71 mag) confirmed naked eye limited magnitude theory. This may explain the inability of observers to perceive Mercury (0.46 mag) using naked eye during the total phase of solar eclipse.

  12. Ionospheric Disturbances Observed during Earthquakes and Solar Eclipses at Tashkent and Kitab GPS Stations

    Science.gov (United States)

    Ahmedov, Bobomurat

    2016-07-01

    Since the Global Positioning System (GPS) data can be used to measure the ionospheric TEC, the technique has received our attention as a potential tool to detect ionospheric perturbations related to the earthquakes and we mainly analysed GPS derived TEC disturbances from two GPS stations located in Tashkent and Kitab, for possible earthquake ionospheric precursors. This talk reports the ionospheric anomalies observed during strong local earthquakes (M greater than 5.0) which occurred mostly in and around Uzbekistan in seismically active zones, during years 2010 to 2015 within 1000 km from the observing GPS stations located in Tashkent and Kitab. The solar and geomagnetic conditions were quiet during occurrence of the selected more than 30 earthquakes. We produced TEC time series over both sites and apply them to detect anomalous TEC signals preceding or accompanying the earthquakes. The results show anomalous enhancements which are examined in the earthquakes. In general the anomalies occurred 1-6 days before the earthquakes as ionospheric electromagnetic precursors. To identify the anomalous values of TEC we calculated differential TEC (dTEC). dTEC is obtained by subtracting 15 days backward running mean of vTEC from the values of observed vTEC at each epoch. This procedure removes normal variations in TEC. For a detail study of the data, we have calculated dTEC values for all the months and examined the anomalous TEC variations before the earthquakes. A thorough analysis of the data shows abnormal variations in TEC and ionospheric anomalies, such as variations in the electron density few days before the earthquakes, may play a role of one of the electromagnetic precursory signals of earthquakes. TEC decrease during the solar eclipses is also obtained from data at GPS station in Tashkent and Kitab. During the solar flares occurrence the amplitude of TEC is amplified with compare to the nondisturbed initial monthly mean background value after the flare.

  13. Multi-instrument observations of the solar eclipse on 20 March 2015 and its effects on the ionosphere over Belgium and Europe

    Directory of Open Access Journals (Sweden)

    Stankov Stanimir M.

    2017-01-01

    Full Text Available A total solar eclipse occurred on 20 March 2015, with a totality path passing mostly above the North Atlantic Ocean, which resulted in a partial solar eclipse over Belgium and large parts of Europe. In anticipation of this event, a dedicated observational campaign was set up at the Belgian Solar-Terrestrial Centre of Excellence (STCE. The objective was to perform high-quality observations of the eclipse and the associated effects on the geospace environment by utilising the advanced space- and ground-based instrumentation available to the STCE in order to further our understanding of these effects, particularly on the ionosphere. The study highlights the crucial importance of taking into account the eclipse geometry when analysing the ionospheric behaviour during eclipses and interpreting the eclipse effects. A detailed review of the eclipse geometry proves that considering the actual obscuration level and solar zenith angle at ionospheric heights is much more important for the analysis than at the commonly referenced Earth’s surface or at the plasmaspheric heights. The eclipse occurred during the recovery phase of a strong geomagnetic storm which certainly had an impact on (some of the ionospheric characteristics and perhaps caused the omission of some “low-profile” effects. However, the analysis of the ionosonde measurements, carried out at unprecedented high rates during the eclipse, suggests the occurrence of travelling ionospheric disturbances (TIDs. Also, the high temporal and spatial resolution measurements proved very important in revealing and estimating some finer details of the delay in the ionospheric reaction and the ionospheric disturbances.

  14. Impacts of the solar eclipse of 11 August 1999 on routinely recorded meteorological and air quality data in south-west Germany

    Directory of Open Access Journals (Sweden)

    Dieter Ahrens

    2001-05-01

    Full Text Available The total solar eclipse of 11 August 1999 over Central Europe was also visible in Baden-Wuerttemberg, a state in south-west Germany. To investigate the impact of the total solar eclipse on the lower planetary boundary layer, meteorological and air quality data extracted from routine measurements at six sites in Baden-Wuerttemberg were examined. The meteorological data were recorded at the Plittersdorf meteorological station (in the path of totality of the total solar eclipse and at the Forest meteorological Site Hartheim (outside the path of totality of the total solar eclipse. The air quality data were obtained from four official air quality monitoring stations located at Freudenstadt, Karlsruhe-West, Rastatt and Welzheimer Wald, all of which lie within the path of totality of the total solar eclipse. Due to cloudiness, weather conditions on 11 August 1999 were not optimal in south-west Germany. However, the transient reduction (followed by a rise induced by the total solar eclipse on meteorological variables including global solar radiation, upward longwave radiation, net radiation, air temperature, horizontal wind speed, elevation angle of the three-dimensional wind vector as well as turbulent sensible and latent heat fluxes was quite obvious. Despite unfavourable weather conditions, half-hourly mean values of ozone routinely measured at the above-mentioned standard official air quality monitoring stations showed a varying decline up to 27% at the urban station Rastatt and 37% at the background station Welzheimer Wald. This decline was owing mainly to the fall in global radiation during the total solar eclipse. However, additional influences by advection and deposition can not be precluded.

  15. Hybrid Silicon Nanocone–Polymer Solar Cells

    KAUST Repository

    Jeong, Sangmoo

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm 2, which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution. © 2012 American Chemical Society.

  16. Sunspots sketches during the solar eclipses of 9th January and 29th December of 1777 in Mexico

    Science.gov (United States)

    Domínguez-Castro, Fernando; Gallego, María Cruz; Vaquero, José Manuel

    2017-06-01

    Two sunspot observations recorded by the Mexican Felipe de Zúñiga y Ontiveros have been revealed from a manuscript. One sunspot group was recorded on 9th January 1777 and four sunspot groups on 29th December 1777. Both records were taken during the observation of solar eclipses from Mexico City and their description also included sketches of the solar disk with sunspots. The sunspot group corresponding to 9th January was also observed by Erasmus Lievog. The observation on 29th December 1777 is the only record corresponding to this date.

  17. First results from the NASA WB-57 airborne observations of the Great American 2017 Total Solar Eclipse

    Science.gov (United States)

    Caspi, Amir; Tsang, Constantine; DeForest, Craig; Seaton, Daniel B.; Bryans, Paul; Tomczyk, Steven; Burkepile, Joan; Judge, Phil; DeLuca, Edward E.; Golub, Leon; Gallagher, Peter T.; Zhukov, Andrei; West, Matthew; Durda, Daniel D.; Steffl, Andrew J.

    2017-08-01

    Total solar eclipses present rare opportunities to study the complex solar corona, down to altitudes of just a few percent of a solar radius above the surface, using ground-based and airborne observatories that would otherwise be dominated by the intense solar disk and high sky brightness. Studying the corona is critical to gaining a better understanding of physical processes that occur on other stars and astrophysical objects, as well as understanding the dominant driver of space weather that affects human assets at Earth and elsewhere. For example, it is still poorly understood how the corona is heated to temperatures of 1-2 MK globally and up to 5-10 MK above active regions, while the underlying chromosphere is 100 times cooler; numerous theories abound, but are difficult to constrain due to the limited sensitivities and cadences of prior measurements. The origins and stability of coronal fans, and the extent of their reach to the middle and outer corona, are also not well known, limited in large part by sensitivities and fields of view of existing observations.Airborne observations during the eclipse provide unique advantages; by flying in the stratosphere at altitudes of 50 kft or higher, they avoid all weather, the seeing quality is enormously improved, and additional wavelengths such as near-IR also become available due to significantly reduced water absorption. For an eclipse, an airborne observatory can also follow the shadow, increasing the total observing time by 50% or more.We present the first results from airborne observations of the 2017 Great American Total Solar Eclipse using two of NASA's WB-57 research aircraft, each equipped with two 8.7" telescopes feeding high-sensitivity visible (green-line) and near-IR (3-5 µm) cameras operating at high cadence (30 Hz) with ~3 arcsec/pixel platescale and ±3 R_sun fields of view. The aircraft will fly along the eclipse path, separated by ~90 km, to observe a summed ~8 minutes of totality in both visible and

  18. Total solar eclipse education for young generation at Palangkaraya, Central Kalimantan

    Science.gov (United States)

    Fatima, S.; Widyanita; Fahriyah, H.; Rhodiyah, A. K.; Satrya, C. D.; Hilmi, M.; Ramadhania, G. E.; Naufal, L.; Mulki, F. A. M.; Herdiwijaya, D.

    2016-11-01

    The path of Total Solar Eclipse (TSE) on March 9th 2016 passed through several cities in Indonesia and one of them is Palangkaraya, Central Kalimantan. The TSE natural phenomenon provided a special moment and gave unforgettable and lifelong experiences for children who live in Palangkaraya. Some miss-information and a bad impression can be felt by children who do not understand about TSE that causes momentary darkness during totality phase. Therefore we designed a children education programs about the TSE that as follow: (1) socialization about TSE, (2) Popular astronomy seminar, (3) How to observe the Sun? (4) writing competition about TSE and (5) TSE observation. The events were held on March 8th - 9th 2016. More than 200 representatives of elementary school students and teachers throughout Palangkaraya have actively participated. The keynote speaker was an Indonesian expert astronomer with help from alumni of astronomy olympiad in order to provide inspiration for the participants, especially to the students. We conclude that students as young generation of the nation may have more motivation to work in science by direct learning from natural phenomena.

  19. Micrometeorological measurements during the total solar eclipse of August 11, 1999

    Directory of Open Access Journals (Sweden)

    Thomas Foken

    2001-05-01

    Full Text Available Micrometeorological measurements of radiation, atmospheric and soil parameters, and turbulent energy and momentum fluxes, ozone and carbon dioxide fluxes have been conducted over a maize field at Freising-Weihenstephan in Southern Germany during the total solar eclipse on August 11, 1999. For the period 30 minutes before and after the totality the weather conditions at the location where the micrometeorological measurements were made was satisfactory. Several connections between the irradiation and other meteorological parameters over a maize field have been found. The time response between irradiation and the long-wave upward radiation was only a few minutes, whereas almost all parameters caused by the turbulent transport had a time shift of up to 30 minutes. A period of nearly 30 minutes with reduced turbulence regime after the totality was found. Using a wavelet transformation for the time series, a change of time scales from longer to shorter ones was observed before the totality, and after the turbulence increased in the short time scales. The investigation of the residuum of the closure of the energy balance showed that with a time shift for the latent heat flux (unlike the net radiation after the totality, a better energy budget closure was obtained.

  20. Broadband radio spectral observations of the solar eclipse on 2008-08-01 and its implications on the quiet Sun atmospheric model

    Institute of Scientific and Technical Information of China (English)

    TAN BaoLin; CHEN LinJie; JI GuoShu; YAN YiHua; ZHANG Yin; TAN ChengMin; HUANG Jing; LIU YuYing; FU QiJun; CHEN ZhiJun; LIU Fei

    2009-01-01

    Based on the joint-observations of the radio broadband spectral emissions of the solar eclipse on Au-gust 1, 2008 at Jiuquan (total eclipse) and Huairou (partial eclipse) at the frequencies of 2.00-5.60 GHz (Jiuquan), 2.60-3.80 GHz (Chinese solar broadband radiospectrometer, SBRS/Huairou), and 5.20-7.60 GHz (SBRS/Huairou), the authors assemble a successive series of broadband spectra with a frequency of 2.60-7.60 GHz to observe the solar eclipse synchronously. This is the first attempt to analyze the solar eclipse radio emission under the two telescopes located at different places with broadband frequencies in the periods of total and partial eclipses. With these analyses, the authors made a semiempirical model of the coronal plasma density of the quiet Sun, which can be expressed as n_e≌1.42×10~9(r~(-2)+1.93r~(-5)) (cm~(-3)), in the space range of r=1.039-1.212 R_⊙, and made a comparison with the classic model.

  1. Broadband radio spectral observations of the solar eclipse on 2008-08-01 and its implications on the quiet Sun atmospheric model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Based on the joint-observations of the radio broadband spectral emissions of the solar eclipse on August 1, 2008 at Jiuquan (total eclipse) and Huairou (partial eclipse) at the frequencies of 2.00-5.60 GHz (Jiuquan), 2.60-3.80 GHz (Chinese solar broadband radiospectrometer, SBRS/Huairou), and 5.20-7.60 GHz (SBRS/Huairou), the authors assemble a successive series of broadband spectra with a frequency of 2.60-7.60 GHz to observe the solar eclipse synchronously. This is the first attempt to analyze the solar eclipse radio emission under the two telescopes located at different places with broadband frequencies in the periods of total and partial eclipses. With these analyses, the authors made a semiempirical model of the coronal plasma density of the quiet Sun, which can be expressed as ne 1.42×109(r-2+1.93r-5) (cm-3), in the space range of r=1.039-1.212 R , and made a comparison with the classic model.

  2. Analysis of hybrid solar systems

    Science.gov (United States)

    Swisher, J.

    1980-10-01

    The TRNSYS simulation program was used to evaluate the performance of active charge/passive discharge solar systems with water as the working fluid. TRNSYS simulations are used to evaluate the heating performance and cooling augmentation provided by systems in several climates. The results of the simulations are used to develop a simplified analysis tool similar to the F-chart and Phi-bar procedures used for active systems. This tool, currently in a preliminary stage, should provide the designer with quantitative performance estimates for comparison with other passive, active, and nonsolar heating and cooling designs.

  3. The centre-to-limb variations of solar Fraunhofer lines imprinted upon lunar eclipse spectra - Implications for exoplanet transit observations

    CERN Document Server

    Yan, Fei; Petr-Gotzens, Monika G; Zhao, Gang; Pallé, Enric

    2015-01-01

    The atmospheres of exoplanets are commonly studied by observing the transit of the planet passing in front of its parent star. The obscuration of part of the stellar disk during a transit will reveal aspects of its surface structure resulting from general centre-to-limb variations (CLVs). These become apparent when forming the ratio between the stellar light in and out of transit. These phenomena can be seen particularly clearly during the progress of a penumbral lunar eclipse, where the Earth transits the solar disk and masks different regions of the solar disk as the eclipse progresses. When inferring the properties of the planetary atmosphere, it is essential that this effect originating at the star is properly accounted for. Using the data observed from the 2014-April-15 lunar eclipse with the ESPaDOnS spectrograph mounted on the Canada France Hawaii Telescope (CFHT), we have obtained for the first time a time sequence of the penumbral spectra. These penumbral spectra enable us to study the centre-to-limb...

  4. UBVRI Observations And Analysis Of The Solar Type, Total Eclipsing Binary, TYC 3034-299-1

    Science.gov (United States)

    Faulkner, Danny R.; Blum, N.; Samec, R. G.; Jaso, A.; Smith, P. M.; White, J.; Van Hamme, W.

    2012-01-01

    TYC 3034-299-1 (CVn) is a magnetically active, solar type contact binary and a ROTSE variable. This system was observed as a part of our continuing student/professional collaborative study of interacting binaries. The current UBVRI light curves were taken with the Lowell 0.81-m reflector in Flagstaff on May 10 and May 11, 2010. Four times of minimum light were determined from our observations. They include (with standard errors): HJD I = 2455326.72754±0.00024, 2455327.713303±0.00025, HJD II = 2455326.92427±0.00068, 2455327.91256±0.00060. We also obtained the following timings of minimum light from parabolic fits to the data of Blattler (IBVS number 5699, 2006): HJD I = 2453382.6915, 2453445.4980, 2453502.3800, 2453515.4154, 2453517.3907, HJD II = 2453463.4719, 2453515.607. From these and Nelson's (IBVS numbers 5875 and 5929, 2009) observations, an improved ephemeris was calculated from all the available eclipse timings: J.D. Hel Min I = 2455326.9244±0.0005 + 0.39500870 ± 0.00000016 d*E. Our light curve amplitudes are deep for a contact binary, ranging from 0.85 magnitude in U to 0.66 in I. Time of totality of 7 minutes was detected in the secondary eclipse indicating that this system is a W-type W UMa system (less massive star is hotter). The O'Connell effect ranges from 67 mmag to 36 mmag in U to I, respectively, revealing substantial magnetic activity. A 5-color simultaneous light curve solution was calculated using the Wilson Code. Our model reveals a dark spot region at longitude 58°. The 18% fill-out and the virtually identical temperatures of the two stars show that the system has nearly reached thermal contact. We performed a q-search over the interval from q = 0.3 to 0.8. The mass ratio is 0.46. We wish to thank Lowell Observatory for their allocation of observing time and the American Astronomical Society and the Arizona Space Grant for travel support for this observing run.

  5. The solar diameter on 9 March 2016, from the total eclipse in Micronesia: at its standard value

    Science.gov (United States)

    Sigismondi, Costantino; Castiglioni, Francesco; Cicogna, Domenico; Cardoso, Felipe

    2016-05-01

    The total eclipse of 9 March 2016 has been observed in Woleai atoll (Micronesia) by the Exploratorium team and posted in youtube. Exploiting the ghost images of that video we overcome the overexposition problems when dealing with the transition photosphere/chromosphere, dealing with Baily's beads around totality comparable with the intensity of the corona. A correction to the standard value of the solar radius R=959.63" of ΔR=+0.01"±0.02" has been found, contrarily to the recent values near 960.0" with the last eclipses and transit of Venus. Perspectives for the measures to be done during the forthcoming transit of Mercury are drafted.

  6. Hybrid solar cell on a carbon fiber

    Science.gov (United States)

    Grynko, Dmytro A.; Fedoryak, Alexander N.; Smertenko, Petro S.; Dimitriev, Oleg P.; Ogurtsov, Nikolay A.; Pud, Alexander A.

    2016-05-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode.

  7. Hybrid nanorod-polymer solar cells.

    Science.gov (United States)

    Huynh, Wendy U; Dittmer, Janke J; Alivisatos, A Paul

    2002-03-29

    We demonstrate that semiconductor nanorods can be used to fabricate readily processed and efficient hybrid solar cells together with polymers. By controlling nanorod length, we can change the distance on which electrons are transported directly through the thin film device. Tuning the band gap by altering the nanorod radius enabled us to optimize the overlap between the absorption spectrum of the cell and the solar emission spectrum. A photovoltaic device consisting of 7-nanometer by 60-nanometer CdSe nanorods and the conjugated polymer poly-3(hexylthiophene) was assembled from solution with an external quantum efficiency of over 54% and a monochromatic power conversion efficiency of 6.9% under 0.1 milliwatt per square centimeter illumination at 515 nanometers. Under Air Mass (A.M.) 1.5 Global solar conditions, we obtained a power conversion efficiency of 1.7%.

  8. A Check on the Variations of Earth's Rotation with an Ancient Solar Eclipse

    Institute of Scientific and Technical Information of China (English)

    Yan-Ben Han; Qi-Yuan Qiao

    2003-01-01

    We address the relation between an ancient total eclipse, which occurred on A.D.1542 August 11 and the variation of Earth's rotation. The total eclipse was recorded in some ancient Chinese books, especially in local chronicles. Some of the documents include useful information for determining the location of the totality zone. The parameters of the eclipse are calculated by using the DE406 Ephemeris.A high-precision value of AT which expresses the variation of the Earth's rotation,of about 300 ~ 380 s, is obtained.

  9. Solar disc radius determined from observations made during eclipses with bolometric and photometric instruments on board the PICARD satellite

    Science.gov (United States)

    Thuillier, G.; Zhu, P.; Shapiro, A. I.; Sofia, S.; Tagirov, R.; van Ruymbeke, M.; Perrin, J.-M.; Sukhodolov, T.; Schmutz, W.

    2017-07-01

    Context. Despite the importance of having an accurate measurement of the solar disc radius, there are large uncertainties of its value due to the use of different measurement techniques and instrument calibration. An item of particular importance is to establish whether the value of the solar disc radius correlates with the solar activity level. Aims: The main goal of this work is to measure the solar disc radius in the near-UV, visible, and near-IR regions of the solar spectrum. Methods: Three instruments on board the PICARD spacecraft, namely the Bolometric Oscillations Sensor (BOS), the PREcision MOnitoring Sensor (PREMOS), and a solar sensor (SES), are used to derive the solar disc radius using the light curves produced when the Sun is occulted by the Moon. Nine eclipses, from 2010 to 2013, resulted in 17 occultations as viewed from the moving satellite. The calculation of the solar disc radius uses a simulation of the light curve taking into account the center-to-limb variation provided by the Non-local thermodynamic Equilibrium Spectral SYnthesis (NESSY) code. Results: We derive individual values for the solar disc radius for each viewed eclipse. Tests for a systematic variation of the radius with the progression of the solar cycle yield no significant results during the three years of measurements within the uncertainty of our measurements. Therefore, we derive a more precise radius value by averaging these values. At one astronomical unit, we obtain 959.79 arcseconds (arcsec) from the bolometric experiment; from PREMOS measurements, we obtain 959.78 arcsec at 782 nm and 959.76 arcsec at 535 nm. We found 960.07 arcsec at 210 nm, which is a higher value than the other determinations given the photons at this wavelength originate from the upper photosphere and lower chromosphere. We also give a detailed comparison of our results with those previously published using measurements from space-based and ground-based instruments using the Moon angular radius

  10. Broad band photometry of solar corona during the total solar eclipse of October 24, 1995.

    Science.gov (United States)

    Bagare, S. P.; Aleem, P. S. M.; Singh, J.; Saxena, A. K.

    A 30 cm coelostat, a red broad band filter, and a 15 cm objective providing an f/15 beam were used to obtain high resolution pictures of the white light solar corona. In one of the frames, the presence of a loop structure is recorded with its top around 2 Rsun, in the near north polar region. The nearest YOHKOH soft X-ray picture shows the presence of a coronal hole with its border apparently beneath the loop structure. The preliminary results are discussed.

  11. SAMI3 prediction of the impact of the 21 August 2017 total solar eclipse on the ionosphere/plasmasphere system

    Science.gov (United States)

    Huba, J. D.; Drob, D.

    2017-06-01

    We present quantitative predictions of the impact of the upcoming total solar eclipse on the ionosphere and plasmasphere using the Naval Research Laboratory (NRL) model Sami3 is Also a Model of the Ionosphere (SAMI3). The eclipse will occur over the continental United States on 21 August 2017. Our simulation results indicate that in the vicinity of the eclipse (1) the total electron content (TEC) decreases by up to ˜ 5 TEC units (TECU; 1 TECU = ×1016 m-2) which is a ˜ 35% decrease in TEC, (2) the electron density decreases by a factor of ˜ 50% in the F region, (3) the electron temperature decreases by up to ˜800 K in the plasmasphere, and (4) the O+ velocity changes from ˜40 m s-1 upward to ˜20 m s-1 downward in the F region. Interestingly, the continental size modification of the ionospheric conductance modifies the global electric field, which should lead to measurable changes in the TEC in the southern conjugate hemisphere (≲1 TECU).

  12. Search for Rapid Changes in the Visible-Light Corona during the 21 June 2001 Total Solar Eclipse

    CERN Document Server

    Rudawy, P; Buczylko, A; Williams, D R; Keenan, F P

    2010-01-01

    Some 8000 images obtained with the SECIS fast-frame CCD camera instrument located at Lusaka, Zambia, during the total eclipse of 21 June 2001 have been analyzed to search for short-period oscillations in intensity that could be a signature of solar coronal heating mechanisms by MHD wave dissipation. Images were taken in white- light and Fe XIV green-line (5303 A) channels over 205 seconds (frame rate 39 s-1), approximately the length of eclipse totality at this location, with a pixel size of four arcseconds square. The data are of considerably better quality than were obtained during the 11 August 1999 total eclipse, observed by us (Rudawy et al.: Astron. Astrophys. 416, 1179, 2004), in that the images are much better exposed and enhancements in the drive system of the heliostat used gave a much improved image stability. Classical Fourier and wavelet techniques have been used to analyze the emission at 29518 locations, of which 10714 had emission at reasonably high levels, searching for periodic fluctuations ...

  13. Aerosol Lidar observations and model calculations of the Planetary Boundary Layer evolution over Greece, during the March 2006 Total Solar Eclipse

    Directory of Open Access Journals (Sweden)

    V. Amiridis

    2007-12-01

    Full Text Available An investigation of the Planetary Boundary Layer (PBL height evolution over Greece, during the solar eclipse of 29 March 2006, is presented. Ground based observations were carried out using lidar detection and ranging devices and ground meteorological instruments, to estimate the height of the mixing layer (ML before, during and after the solar eclipse in northern and southern parts of Greece exhibiting different sun obscuration. Data demonstrate that the solar eclipse has induced a decrease of the PBL height, indicating a suppression of turbulence activity similar to that during the sunset hours. The changes in PBL height were associated with a very shallow entrainment zone, indicating a significant weakening of the penetrative convection. Heat transfer was confined to a thinner layer above the ground. The thickness of the entrainment zone exhibited its minimum during the maximum of the eclipse, demonstrative of turbulence mechanisms suppression at that time. Model estimations of the PBL evolution were additionally conducted using the Comprehensive Air Quality Model with extensions (CAMx coupled with the Weather Research and Forecasting model (WRF. Model-diagnosed PBL height decrease during the solar eclipse due to vertical transport decay, in agreement with the experimental findings; vertical profiles of atmospheric particles and gaseous species showed an important vertical mixing attenuation.

  14. Aerosol lidar observations and model calculations of the planetary boundary layer evolution over Greece, during the March 2006 total solar eclipse

    Directory of Open Access Journals (Sweden)

    V. Amiridis

    2007-09-01

    Full Text Available An investigation of the Planetary Boundary Layer (PBL height evolution over Greece, during the solar eclipse of 29 March 2006, is presented. Ground based observations were carried out using lidar detection and ranging devices (Lidars and ground meteorological instruments, to estimate the height of the Mixing Layer (ML before, during and after the solar eclipse in Northern and Southern parts of Greece exhibiting different sun obscuration. Data demonstrate that the solar eclipse has induced a decrease of the PBL height, indicating a suppression of turbulence activity similar to that during the sunset hours. The changes in PBL height were associated with a very shallow entrainment zone, indicating a significant weakening of the penetrative convection. Heat transfer was confined to a thinner layer above ground. The thickness of the entrainment zone exhibited its minimum during the maximum of the eclipse, demonstrative of turbulence mechanisms suppression at that time. Model estimations of the PBL evolution were additionally conducted using the Comprehensive Air Quality Model with extensions (CAMx coupled with the Weather Research and Forecasting model (WRF. Model diagnosed PBL height decrease during the solar eclipse due to vertical transport decay, in agreement with the experimental findings; vertical profiles of atmospheric particles and gaseous species showed an important vertical mixing attenuation.

  15. Observations of the atmospheric surface layer parameters over a semi arid region during the solar eclipse of August 11th, 1999

    Indian Academy of Sciences (India)

    Praveena Krishnan; P K Kunhikrishnan; S Muraleedharan Nair; Sudha Ravindran; Radhika Ramachandran; D B Subrahamanyam; M Venkata Ramana

    2004-09-01

    This paper discusses the observations of the Atmospheric Surface Layer (ASL) parameters during the solar eclipse of August 11th, 1999. Intensive surface layer experiments were conducted at Ahmedabad (23° 21′N, 72° 36′E), the western part of India, which was close to the totality path. This rare event provided by nature is utilised to document the surface layer effects during the eclipse period using measurements of high frequency fluctuations of temperature, tri-axial wind components as well as mean parameters such as temperature, humidity, wind speed and subsoil temperature. Analysis showed that during the eclipse period, the turbulence parameters were affected leading to the suppression of the turbulence process, the main dynamic process in the atmospheric boundary layer, while the mean parameters showed variations within the natural variability of the observational period. The spectra of the wind components and temperature indicated decrease in spectral power by one order in magnitude during the eclipse period. The rate of dissipation of turbulent kinetic energy is found to decrease by more than one order during the eclipse period. The stability parameter showed a change from unstable to stable condition during the period of eclipse and back to unstable condition by the end of eclipse.

  16. Thermodynamics of the Solar Corona and Evolution of the Solar Magnetic Field as Inferred from the Total Solar Eclipse Observations of 11 July 2010

    Science.gov (United States)

    Habbal, Shadia Rifai; Druckmueller, Miloslav; Morgan, Huw; Ding, Adalbert; Johnson, Judd; Druckmuellerova, Hana; Daw, Adrian; Arndt, Martina B.; Dietzel, Martin; Saken, Jon

    2011-01-01

    We report on multi-wavelength observations of the corona taken simultaneously in broadband white light, and in seven spectral lines, H-alpha 656.3 nm, Fe IX 435.9 nm, Fe X 637.4 nm, Fe XI 789.2 nm, Fe XIII 1074.7 nm, Fe XIV 530.3 nm and Ni XV 670.2 nm. The observations were made during the total solar eclipse of 11 July 2010 from the atoll of Tatakoto in French Polynesia. Simultaneous imaging with narrow bandpass filters in each of these spectral lines and in their corresponding underlying continua maximized the observing time during less than ideal observing conditions and yielded outstanding quality data. The application of two complementary image processing techniques revealed the finest details of coronal structures at 1" resolution in white light, and 6.5" in each of the spectral lines. This comprehensive wavelength coverage confirmed earlier eclipse findings that the solar corona has a clear two-temperature structure: The open field lines, expanding outwards from the solar surface, are characterized by electron temperatures near 1 X 10(exp 6) K, while the hottest plasma around 2X 10(exp 6) K resides in loop-like structures forming the bulges of streamers. The first images of the corona in the forbidden lines of Fe IX and Ni XV, showed that there was very little coronal plasma at temperatures below 5 X 10(exp 5) K and above 2.5X 10(exp 6) K. The data also enabled temperature differentiations as low as 0:2 X 10(exp 6) K in different density structures. These observations showed how the passage of CMEs through the corona, prior to totality, produced large scale ripples and very sharp streaks, which could be identified with distinct temperatures for the first time. The ripples were most prominent in emission from spectral lines associated with temperatures around 10(exp 6) K. The most prominent streak was associated with a conical-shaped void in the emission from the coolest line of Fe IX and from the hottest line of Ni XV. A prominence, which erupted prior to

  17. Exploring the prominence-corona connection and its expansion into the outer corona using total solar eclipse observations

    Energy Technology Data Exchange (ETDEWEB)

    Habbal, Shadia Rifai [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Morgan, Huw [Institute of Mathematics, Physics and Computer Science, Aberystwyth University, Ceredigion, Cymru SY23 3BZ (United Kingdom); Druckmüller, Miloslav, E-mail: shadia@ifa.hawaii.edu [Faculty of Mechanical Engineering, Brno University of Technology, 616 69 Brno (Czech Republic)

    2014-10-01

    Prominences constitute the most complex magnetic structures in the solar corona. The ubiquitous presence of their seemingly confined dense and cool plasma in an otherwise million-degree environment remains a puzzle. Using a decade of white light total solar eclipse observations, we show how these images reveal an intricate relationship between prominences and coronal structures both in their immediate vicinity, known as coronal cavities, and in the extended corona out to several solar radii. Observations of suspended prominences and twisted helical structures spanning several solar radii are central to these findings. The different manifestations of the prominence-corona interface that emerge from this study underscore the fundamental role played by prominences in defining and controlling the complex expansion and dynamic behavior of the solar magnetic field in the neighborhood of magnetic polarity reversal regions. This study suggests that the unraveling of prominences and the outward expansion of the helical twisted field lines linked to them could be the solar origin of twisted magnetic flux ropes detected in interplanetary space, and of the mechanism by which the Sun sheds its magnetic helicity. This work also underscores the likely role of the prominence-corona interface as a source of the slow solar wind.

  18. A Bicontinuous Double Gyroid Hybrid Solar Cell

    KAUST Repository

    Crossland, Edward J. W.

    2009-08-12

    We report the first successful application of an ordered bicontinuous gyroid semiconducting network in a hybrid bulk heterojunction solar cell. The freestanding gyroid network is fabricated by electrochemical deposition into the 10 nm wide voided channels of a self-assembled, selectively degradable block copolymer film. The highly ordered pore structure is ideal for uniform infiltration of an organic hole transporting material, and solid-state dye-sensitized solar cells only 400 nm thick exhibit up to 1.7% power conversion efficiency. This patterning technique can be readily extended to other promising heterojunction systems and is a major step toward realizing the full potential of self-assembly in the next generation of device technologies. © 2009 American Chemical Society.

  19. Observations of Correlated Behavior of Two Light Torsion Balances and a Paraconical Pendulum in Separate Locations during the Solar Eclipse of January 26th, 2009

    Directory of Open Access Journals (Sweden)

    A. F. Pugach

    2012-01-01

    Full Text Available On January 26th, 2009, simultaneous observations of the reactions of two very light torsion balances (Kiev, Ukraine and a paraconical pendulum (Suceava, Romania, 440 km away were performed during a solar eclipse that was not visible at those locations but only in the Indian Ocean. Significant correlation between the behavior of the torsion balances and the pendulum was observed. The conclusion is that a solar eclipse influences the reactions of torsion balances and pendulums, even in areas of the Earth where it is not optically visible.

  20. High-resolution ionospheric observations and modeling over Belgium during the solar eclipse of 20 March 2015 including first results of ionospheric tilt and plasma drift measurements

    Science.gov (United States)

    Verhulst, Tobias G. W.; Sapundjiev, Danislav; Stankov, Stanimir M.

    2016-06-01

    The ionospheric behavior over Belgium during the partial solar eclipse of 20 March 2015 is analyzed based on high-resolution solar radio flux, vertical incidence sounding, and GPS TEC measurements. First results of ionosonde-based ionospheric plasma drift and tilt observations are presented and analyzed, including some traveling ionospheric disturbances caused by the eclipse. Also, collocated ionosonde and GPS measurements are used to reconstruct the time evolution of the vertical electron density distribution using the Royal Meteorological Institute (RMI) ionospheric specification system, called Local Ionospheric Electron Density profile Reconstruction (LIEDR).

  1. The 3rd Joint Solar Dynamics Project data summary: Solar magnetic field, chromospheric and coronal observations near the time of the 18 March 1988 solar eclipse

    Science.gov (United States)

    Sime, D. G.; Garcia, C. J.; Lundin, W. E.; Yasukawa, E. A.; Mickey, D. L.; Labonte, B.

    1988-11-01

    The general goal of the HAO/University of Hawaii Joint Solar Dynamics Project is to establish the relationships that exist between the solar magnetic field which is detected in the photosphere and the structure and evolution of the corona. The SOLDYN programs of 1982 and 1983 demonstrated the ability to use existing instruments to gather data of value in the pursuit of that goal. The goals for the observations in 1988 are as follows: (1) Document the state of the sun, from the photosphere up through the chromosphere and out into the corona for the approximately four-week interval around the total solar eclipse of 18 March 1988, and (2) Identify the relationship between the photospheric magnetic fields and the temperature and density structure of the corona. The reduced observations made during this SOLDYN 3 period necessary to achieve these goals are provided. The observations are presented both in the form of daily photographic and photo-electric measurements, and in synoptic format for the period.

  2. Joint Solar Dynamics Project data summary (3rd): Solar magnetic field, chromospheric and coronal observations near the time of the 18 March 1988 solar eclipse. Technical note

    Energy Technology Data Exchange (ETDEWEB)

    Sime, D.G.; Garcia, C.J.; Lundin, W.E.; Yasukawa, E.A.

    1988-11-01

    The general goal of the HAO/University of Hawaii Joint Solar Dynamics Project is to establish the relationships that exist between the solar magnetic field, detected in the photosphere, and the structure and evolution of the corona. The SOLDYN programs of 1982 and 1983 demonstrated the ability to use existing instruments to gather data of value in the pursuit of that goal. The goals for the observations in 1988 are as follows: (1) document the state of the sun, from the photosphere up through the chromosphere and out into the corona for the approximately four-week interval around the total solar eclipse of 18 March 1988, and (2) identify the relationship between the photospheric magnetic fields and the temperature and density structure of the corona. This report contains the reduced observations made during this SOLDYN III period necessary to achieve these goals. They are presented both in the form of daily photographic and photoelectric measurements, and in synoptic format for the period.

  3. Electron Temperatures and Flow Speeds of the Low Solar Corona: MACS Results from the Total Solar Eclipse of 29 March 2006 in Libya

    Science.gov (United States)

    Reginald, Nelson L.; Davila, Joseph M.; SaintCyr, O.; Rabin, Douglas M.; Guhathakurta, Madhulika; Hassler, Donald M.; Gashut, Hadi

    2011-01-01

    An experiment was conducted in conjunction with the total solar eclipse on 29 March 2006 in Libya to measure both the electron temperature and its flow speed simultaneously at multiple locations in the low solar corona by measuring the visible K-coronal spectrum. Coronal model spectra incorporating the effects of electron temperature and its flow speed were matched with the measured K-coronal spectra to interpret the observations. Results show electron temperatures of (1.10 +/- 0.05) MK, (0.70 +/- 0.08) MK, and (0.98 +/- 0.12) MK, at 1.1 Solar Radius from Sun center in the solar north, east and west, respectively, and (0.93 +/- 0.12) MK, at 1.2 Solar Radius from Sun center in the solar west. The corresponding outflow speeds obtained from the spectral fit are (103 +/- 92) km/s, (0 + 10) km/s, (0+10) km/s, and (0+10) km/s. Since the observations were taken only at 1.1 Solar Radius and 1.2 Solar Radius from Sun center, these speeds, consistent with zero outflow, are in agreement with expectations and provide additional confirmation that the spectral fitting method is working. The electron temperature at 1.1 Solar Radius from Sun center is larger at the north (polar region) than the east and west (equatorial region).

  4. Electron Temperatures and Flow Speeds of the Low Solar Corona: MACS Results from the Total Solar Eclipse of 29 March 2006 in Libya

    Science.gov (United States)

    Reginald, Nelson L.; Davila, Joseph M.; SaintCyr, O.; Rabin, Douglas M.; Guhathakurta, Madhulika; Hassler, Donald M.; Gashut, Hadi

    2011-01-01

    An experiment was conducted in conjunction with the total solar eclipse on 29 March 2006 in Libya to measure both the electron temperature and its flow speed simultaneously at multiple locations in the low solar corona by measuring the visible K-coronal spectrum. Coronal model spectra incorporating the effects of electron temperature and its flow speed were matched with the measured K-coronal spectra to interpret the observations. Results show electron temperatures of (1.10 +/- 0.05) MK, (0.70 +/- 0.08) MK, and (0.98 +/- 0.12) MK, at 1.1 Solar Radius from Sun center in the solar north, east and west, respectively, and (0.93 +/- 0.12) MK, at 1.2 Solar Radius from Sun center in the solar west. The corresponding outflow speeds obtained from the spectral fit are (103 +/- 92) km/s, (0 + 10) km/s, (0+10) km/s, and (0+10) km/s. Since the observations were taken only at 1.1 Solar Radius and 1.2 Solar Radius from Sun center, these speeds, consistent with zero outflow, are in agreement with expectations and provide additional confirmation that the spectral fitting method is working. The electron temperature at 1.1 Solar Radius from Sun center is larger at the north (polar region) than the east and west (equatorial region).

  5. Total eclipses of the sun.

    Science.gov (United States)

    Zirker, J B

    1980-12-19

    Total eclipses of the sun offer research opportunities in a variety of sciences. Some of the advances in solar physics resulting from eclipse observations are discussed. Experiments at the total eclipse of 16 February 1980 in India are also described. These included a test of general relativity, studies in coronal physics, investigations of solar prominences, diameter measurements, a search for interplanetary dust, a study of the gravity waves in the earth's atmosphere, and experiments on the biological effects on animals and humans.

  6. Development of meteorological parameters and total ozone during the total solar eclipse of August 11, 1999

    Directory of Open Access Journals (Sweden)

    Peter Winkler

    2001-05-01

    Full Text Available During the total eclipse of August 11, 1999 frequent showers occurred due to a unstable stratification of the air mass. At different observation sites, meteorological effects from the eclipse (99.4% coverage at Hohenpeißenberg and from showers were superimposed making it partly difficult to unambiguously interpret the observations. The weather radar at Hohenpeißenberg observatory provided a general overview of the distribution of clouds and precipitation in this area (200 km diameter. From the Garching site in the zone of totality (100% temperature and wind data taken on a 50 m mast were evaluated. By selecting periods with relatively low cloud cover it was possible to approximately follow the development of the vertical temperature and wind profiles during the eclipse. The minimum temperature at Hohenpeißenberg (about 450 m above the altitude of Garching during the eclipse was comparable to that during the previous night, the corresponding value measured at Garching remained about 2 K above the minimum observed during clear sky conditions in the previous night. Showers before, during or after the eclipse may have induced vertical exchange of air parcels. Temperatures during a shower change towards the same direction at all altitudes, thus no inversion forms. Additionally, air parcels with relatively lower concentrations of trace constituents were transported down from aloft for time periods of 10–15 minutes. These mixing processes significantly determined the temporal variations of various trace substances measured during the eclipse. Total ozone measurements at Hohenpeißenberg were performed with both DOBSON and BREWER spectrophotometers and at another site within the zone of totality by using a portable Microtops II filter instrument. Different results were obtained for both sites. These differences can be to a large extend, but not exclusively, attributed to eclipse induced shifts (limb darkening and straylight effects in the atmosphere

  7. Influence of Partial Solar Eclipse 2016 on the surface gravity acceleration using photogate sensor on Kater's reversible pendulum

    Science.gov (United States)

    Nugraha, M. G.; Saepuzaman, D.; Sholihat, F. N.; Ramayanti, S.; Setyadin, A. H.; Ferahenki, A. R.; Samsudin, A.; Utama, J. A.; Susanti, H.; Kirana, K. H.

    2016-11-01

    This study was conducted to determine the Earth's surface gravitational acceleration (g) prior to, during, and after a partial solar eclipse. Data was collected in Basic Physics Laboratory Universitas Pendidikan Indonesia, Bandung with coordinates S 6°51'48", E 107°35'40" for three days on March 8 - 10, 2016, in time interval measurement from 6 a.m. to 9 a.m. This research used a standard pendulum, Kater's reversible pendulum, which deviated less than 3° so that the motion can be regarded harmonics oscillation. The period of pendulum oscillation motion is measured by a light sensor (photogate sensor) with accuracy until 10-13 seconds. The data analysis shows that there is small difference value of gravity acceleration at the Earth's surface from three days of observation, i.e. in the order of 10-3 ms-2. It means, there is a changes in the Earth's surface gravitational acceleration (g) due to the partial solar eclipse but not significant.

  8. Extreme-infrared brightness profile of the solar chromosphere obtained during the total eclipse of 1991

    Science.gov (United States)

    Lindsey, C.; Jefferies, J. T.; Clark, T. A.; Harrison, R. A.; Carter, M. K.; Watt, G.; Becklin, E. E.; Roellig, T. L.; Braun, D. C.; Naylor, D. A.

    1992-01-01

    A temperature profile in 1.3 mm radiation with about 300 km resolution at the sun was obtained during the total eclipse of 1991. The observations indicate that spicules reach a temperature of 8000 K at 3000-4000 km above the photosphere. This temperature is lower than those of many spicule models.

  9. The analysis of total solar eclipse observations on August 11th, 1999 in Kikinda

    Directory of Open Access Journals (Sweden)

    Popović G.M.

    2001-01-01

    Full Text Available Because of poor meteorological conditions, the obtained observational material has not an even distribution in time. Therefore a special method was devised for treating this material. Using this method the durations of total and partial phases of this eclipse were established.

  10. Effects of the solar eclipse on 15 January 2010 on the surface O3, NO, NO2, NH3, CO mixing ratio and the meteorological parameters at Thiruvanathapuram, India

    Directory of Open Access Journals (Sweden)

    R. Gautam

    2010-06-01

    Full Text Available In this paper, we present the effect of total solar eclipse on surface O3, NO, NO2, NH3, CO mixing ratio and the meteorological parameters on 15 January 2010 at Thiruvanathapuram, India. On the day of total solar eclipse (i.e., 15 January 2010, the decrease in mixing ratio of surface O3 and NO2 is observed after the beginning of the solar eclipse events (11:15 to 15:30. Decrease in surface O3 may be due to decreased efficiency of the photochemical ozone formation, whereas, mixing ratio of NO and NH3 have been changed following the night time chemistry. Surface O3 reduced to 20.3 ppb after 22 min of full phase of the eclipse. During the solar eclipse period, the ambient temperature and wind speed have decreased, whereas, relative humidity has increased as expected.

  11. Effects of the solar eclipse on 15 January 2010 on the surface O{sub 3}, NO, NO{sub 2}, NH{sub 3}, CO mixing ratio and the meteorological parameters at Thiruvanathapuram, India

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K.; Mandal, T.K.; Arya, B.C. [Council of Scientific and Industrial Research (CSIR), New Delhi (IN). Radio and Atmospheric Sciences Div.] (and others)

    2010-07-01

    In this paper, we present the effect of total solar eclipse on surface O{sub 3}, NO, NO{sub 2}, NH{sub 3}, CO mixing ratio and the meteorological parameters on 15 January 2010 at Thiruvanathapuram, India. On the day of total solar eclipse (i.e., 15 January 2010), the decrease in mixing ratio of surface O{sub 3} and NO{sub 2} is observed after the beginning of the solar eclipse events (11:15 to 15:30). Decrease in surface O{sub 3} may be due to decreased efficiency of the photochemical ozone formation, whereas, mixing ratio of NO and NH{sub 3} have been changed following the night time chemistry. Surface O{sub 3} reduced to 20.3 ppb after 22 min of full phase of the eclipse. During the solar eclipse period, the ambient temperature and wind speed have decreased, whereas, relative humidity has increased as expected. (orig.)

  12. HYBRID FUEL CELL-SOLAR CELL SPACE POWER SUBSYSTEM CAPABILITY.

    Science.gov (United States)

    This report outlines the capabilities and limitations of a hybrid solar cell- fuel cell space power subsystem by comparing the proposed hybrid system...to conventional power subsystem devices. The comparisons are based on projected 1968 capability in the areas of primary and secondary battery, fuel ... cell , solar cell, and chemical dynamic power subsystems. The purpose of the investigation was to determine the relative merits of a hybrid power

  13. Solar air-conditioning-active, hybrid and passive

    Energy Technology Data Exchange (ETDEWEB)

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  14. Stillwater Hybrid Geo-Solar Power Plant Optimization Analyses

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Daniel S.; Mines, Gregory L.; Turchi, Craig S.; Zhu, Guangdong; Cohan, Sander; Angelini, Lorenzo; Bizzarri, Fabrizio; Consoli, Daniele; De Marzo, Alessio

    2015-09-02

    The Stillwater Power Plant is the first hybrid plant in the world able to bring together a medium-enthalpy geothermal unit with solar thermal and solar photovoltaic systems. Solar field and power plant models have been developed to predict the performance of the Stillwater geothermal / solar-thermal hybrid power plant. The models have been validated using operational data from the Stillwater plant. A preliminary effort to optimize performance of the Stillwater hybrid plant using optical characterization of the solar field has been completed. The Stillwater solar field optical characterization involved measurement of mirror reflectance, mirror slope error, and receiver position error. The measurements indicate that the solar field may generate 9% less energy than the design value if an appropriate tracking offset is not employed. A perfect tracking offset algorithm may be able to boost the solar field performance by about 15%. The validated Stillwater hybrid plant models were used to evaluate hybrid plant operating strategies including turbine IGV position optimization, ACC fan speed and turbine IGV position optimization, turbine inlet entropy control using optimization of multiple process variables, and mixed working fluid substitution. The hybrid plant models predict that each of these operating strategies could increase net power generation relative to the baseline Stillwater hybrid plant operations.

  15. Discovery of a Red Giant with Solar-like Oscillations in an Eclipsing Binary System from Kepler Space-based Photometry

    DEFF Research Database (Denmark)

    Hekker, S.; Debosscher, J.; Huber, D.

    2010-01-01

    Oscillating stars in binary systems are among the most interesting stellar laboratories, as these can provide information on the stellar parameters and stellar internal structures. Here we present a red giant with solar-like oscillations in an eclipsing binary observed with the NASA Kepler satell...

  16. Totality eclipses of the Sun

    CERN Document Server

    Littmann, Mark; Willcox, Ken

    2008-01-01

    A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. - ;A total eclipse of the Sun is the most awesome sight in the heavens. Totality: Eclipses of the Sun takes you to eclipses of the past, present, and future, and lets you see - and feel - why people travel to the ends of the Earth to observe them. Totality: Eclipses of the Sun is the best guide and reference book on solar eclipses ever written. It explains: how to observe them; how to photograph and videotape them; why they occur; their history and mythology; and future eclipses - when and where to see them. Totality also tells the remarkable story of how eclipses shocked scientists, revealed the workings of the Sun, and made Einstein famous. And the book shares the experiences and advice of many veteran eclipse observers. Totality: Eclipses of the Sun is profusely ill...

  17. Hybrid Perovskite/Perovskite Heterojunction Solar Cells.

    Science.gov (United States)

    Hu, Yinghong; Schlipf, Johannes; Wussler, Michael; Petrus, Michiel L; Jaegermann, Wolfram; Bein, Thomas; Müller-Buschbaum, Peter; Docampo, Pablo

    2016-06-28

    Recently developed organic-inorganic hybrid perovskite solar cells combine low-cost fabrication and high power conversion efficiency. Advances in perovskite film optimization have led to an outstanding power conversion efficiency of more than 20%. Looking forward, shifting the focus toward new device architectures holds great potential to induce the next leap in device performance. Here, we demonstrate a perovskite/perovskite heterojunction solar cell. We developed a facile solution-based cation infiltration process to deposit layered perovskite (LPK) structures onto methylammonium lead iodide (MAPI) films. Grazing-incidence wide-angle X-ray scattering experiments were performed to gain insights into the crystallite orientation and the formation process of the perovskite bilayer. Our results show that the self-assembly of the LPK layer on top of an intact MAPI layer is accompanied by a reorganization of the perovskite interface. This leads to an enhancement of the open-circuit voltage and power conversion efficiency due to reduced recombination losses, as well as improved moisture stability in the resulting photovoltaic devices.

  18. Changes of NmF2 and hmF2 over Biak (1°S, 136°E) during total solar eclipse on March 9, 2016

    Science.gov (United States)

    Anggarani, Sefria; Asnawi, Jiyo; Dear, Varuliantor; Ekawati, Sri

    2016-11-01

    Ionospheric responses to solar eclipse is interesting to learn. In this paper, we presented ionspheric F2 responses to total solar eclipse on March 9, 2016 over Indonesia from Biak station (-1 ° 136.0 °) which is within the obscuration 86.55%. The total solar eclipse over Biak occurred at 00:58 UT (09:58 local time) in F2 layer height of ionosphere (h ≈ 300 km). Observation of the ionospheric F2 over Biak during the total solar eclipse investigated using ionosonde with 15 minutes resolution. Ionization and recombination processes that occur in the ionosphere proceed by solar radiation. At the time of the ionosphere receives solar radiation, ionization process dominated in the F2 layer. Diurnal ionosphere parameters changed following the solar radiation. During the solar eclipse, the process of ionization in the F2 layer disturbed. Total solar eclipse on March 9, 2016 affected almost simultaneous decrease in maximum electron density (NmF2) ∼52% and increase hmF2 ∼24% at the elapsed time of totality observed from Biak Station.

  19. Near infrared spectral and polarization imaging observation of coronal emission lines during the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    During the 2008 total solar eclipse, the coronal emission lines were observed by using optical fibre spectrometric and polarization imaging system in near infrared waveband. The profiles of the coronal emission lines including Fe XIII 10747 , 10798  and He I 10830  were obtained with dispersion of 0.5 /pix. The intensity of Fe XIII 10747  remained unchanged in the two different coronal regions while the intensity of He I 10830  varied considerably in the two coronal locations no matter whether the prominence appeared or not. The coronal polarization images were observed at Fe XI 7892  with a bandpass of 30  in a series of exposure times.

  20. Near infrared spectral and polarization imaging observation of coronal emission lines during the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    BAO XingMing; WANG XiaoFan; ZHANG ZhiYong; DENG Jian; HU KeLiang; XUAN WeiJia; LIU YangBing; ZHANG HongQi; DENG YuanYong; WANG DongGuang

    2009-01-01

    During the 2008 total solar eclipse, the coronal emission lines were observed by using optical fibre spectrometric and polarization imaging system in near infrared waveband. The profiles of the coronal emission lines Including Fe ⅩⅢ 10747 A, 10798 A and He 1 10830 A were obtained with dispersion of 0.5 A/pix. The intensity of Fe ⅩⅢ 10747 A remained unchanged In the two different coronal regions while the intensity of He I 10830 A varied considerably in the two coronal locations no matter whether the prominence appeared or not. The coronal polarization images were observed at Fe XI 7892 A with a bandpass of 30 A in a series of exposure times.

  1. Energy Efficient Hybrid Dual Axis Solar Tracking System

    Directory of Open Access Journals (Sweden)

    Rashid Ahammed Ferdaus

    2014-01-01

    Full Text Available This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

  2. BVRI Photometric 2015 WD Analysis of the Southern Totally Eclipsing, Solar-type, Shallow-contact W UMa Binary, DD Indus

    Science.gov (United States)

    Samec, Ronald G.; Norris, Cody L.; Van Hamme, Walter; Faulkner, Danny R.; Hill, Robert L.

    2016-12-01

    Observations and a 2015 Wilson-Devinney Program analysis are undertaken for the first precision observations of DD Indi. DD Indi is of solar-type (T 1 ˜ 5750 K) and was determined to be a shallow-contact eclipsing binary. It was observed from 2013 June through September at Cerro Tololo InterAmerican Observatory in remote mode. The 24 inch Boller and Chivens reflector, now under management by The Southeastern Association for Resarch in Astronomomy (SARA) was used. Five new eclipse timings were obtained, for three primary and two secondary eclipses. Seven more eclipse timings were calculated from All Sky Automated Survey data. A possibly increasing period was found from all available eclipse timings with a 5 ± 2 × 10-11 × E 2 quadratic term. A BVR c I c simultaneous synthetic light-curve analysis reveals that the system has a mass ratio of ˜0.46, a ˜ 140 K component temperature difference, and two weak cool spots. The Roche Lobe fill-out of this W-type binary is only ˜11%, and an inclination of ˜86° was determined. A time of constant light of ˜16 minutes is measured around phase zero. More detail is included in this report.

  3. [Multifocal electroretinogram for assessing sun damage following the solar eclipse of 11 August 1999].

    Science.gov (United States)

    Mack, G; Uzel, J L; Sahel, J; Flament, J

    2002-04-01

    Following the eclipse of 11 August 1999, the ophthalmological clinic of Strasbourg cared for 4 patients who suffered from sun damage. The multifocal electroretinogram (ERG) carried out on our first patient enabled us to not only confirm the existence of a residual maculopathy as shown by the static visual field, but also, and above all to quantify the foveolar deficit. Moreover, with the other 3 patients, the multifocal ERG enabled us to detect a foveolar deficit completely overlooked by the other usual tests. In light of our clinical study, we can assert that the multifocal ERG has yet to be equaled by any other test for analysis of macular function.

  4. Nationwide Eclipse Ballooning Project

    Science.gov (United States)

    Colman Des Jardins, Angela; Berk Knighton, W.; Larimer, Randal; Mayer-Gawlik, Shane; Fowler, Jennifer; Harmon, Christina; Koehler, Christopher; Guzik, Gregory; Flaten, James; Nolby, Caitlin; Granger, Douglas; Stewart, Michael

    2016-05-01

    The purpose of the Nationwide Eclipse Ballooning Project is to make the most of the 2017 rare eclipse event in four main areas: public engagement, workforce development, partnership development, and science. The Project is focused on two efforts, both student-led: online live video of the eclipse from the edge of space and the study of the atmospheric response to the eclipse. These efforts, however, involving more than 60 teams across the US, are challenging in many ways. Therefore, the Project is leveraging the NASA Space Grant and NOAA atmospheric science communities to make it a success. The first and primary topic of this poster is the NASA Space Grant supported online live video effort. College and high school students on 48 teams from 31 states will conduct high altitude balloon flights from 15-20 locations across the 8/21/2017 total eclipse path, sending live video and images from near space to a national website. Video and images of a total solar eclipse from near space are fascinating and rare. It’s never been done live and certainly not in a network of coverage across a continent. In addition to the live video to the web, these teams are engaged in several other science experiments as secondary payloads. We also briefly highlight the eclipse atmospheric science effort, where about a dozen teams will launch over one hundred radiosondes from across the 2017 path, recording an unprecedented atmospheric data sample. Collected data will include temperature, density, wind, humidity, and ozone measurements.

  5. VLF signal modulations during the total solar eclipse of 22nd July, 2009: model using D region ion chemistry and LWPC

    Science.gov (United States)

    Chakraborty, Suman; Chakrabarti, Sandip Kumar; Palit, Sourav; Ray, Suman

    2016-07-01

    One of the major sources of ionospheric perturbations is variations in solar Extreme Ultraviolet (EUV) radiation flux. Solar eclipse is a phenomenon which is capable of producing significant effects on the physical and chemical properties of the ionospheric plasma. During a solar eclipse, the solar radiation flux reduces considerably for a limited period of time over specific locations on the Earth. This induces certain changes within the ionosphere or more precisely, in the D-region which can be studied with the observation of Very Low Frequency (VLF) radio signal modulations. The parameters which mainly govern the ion-chemistry, such as the recombination coefficients are poorly known till date. Solar eclipse provides us with an excellent opportunity to study these parameters as its time of occurrence is known beforehand and thus we can equip ourselves accordingly. In the present study we considered the Total Solar Eclipse (TSE) that occurred on 22nd July, 2009 within the Indian subcontinent. Indian Centre for Space Physics (ICSP) conducted a week long campaign during the eclipse and data were recorded from dozens of places within India and abroad. Both positive and negative changes in VLF signal amplitude were observed. In this paper, data for a propagation path between Indian Navy VLF transmitter named VTX3 and a pair of receivers in India, namely Malda and Kolkata are used. We start with calculating the obscuration function for these two places to find the variations in ionization flux within the period of the eclipse. After this, we incorporated the D region ion chemistry model to find the equilibrium ion density over the region and employ the LWPC code to find the VLF signal amplitude. We varied the values of recombination coefficients to achieve desired accuracy in our results. In doing so, we achieved two goals: First, we have been able to reproduce the trend of variation in VLF signal amplitude (both positive and negative) at both the receiving locations

  6. Photodecomposition Profile of Organic Material during the Partial Solar Eclipse of 9 March 2016 and Its Correlation with Organic Material Concentration and Photocatalyst Amount

    Directory of Open Access Journals (Sweden)

    Asep Bayu Dani Nandiyanto

    2016-09-01

    Full Text Available The present study investigated the photodecomposition of an organic material during the partial (88.76% solar eclipse phenomenon of 9 March 2016 in Bandung, Indonesia. Curcumin and anatase titanium dioxide (TiO2 particles were used as models of organic material and photocatalyst, respectively. The influence of the process parameters (i.e., curcumin concentration and the amount of TiO2 on the photodecomposition process was also investigated. The results showed that the curcumin was decomposed along with the solar light irradiation time. During the solar eclipse, the photodecomposition rate is suddenly down. The partial solar eclipse provided a slower photodecomposition process than the process under sunny days (conducted on 8 and 10 March 2016. The concentration of curcumin and the amount of TiO2 also have played an important role in the photodecomposition, in which the lower concentration of curcumin and the higher amount of TiO2 have a correlation to the obtainment of higher photodecomposition rate.

  7. Response of low latitude D-region ionosphere to the Total Solar Eclipse of 22 July 2009, deduced from ELF/VLF analysis

    Science.gov (United States)

    Singh, A. K.; Singh, R.; Singh, A. K.

    2011-12-01

    Response of the D-region of the ionosphere to the total solar eclipse of 22 July 2009 at low latitude, Varanasi (geomagnetic lat = 140 55'N, longitude = 1540 E, dip. angle = 37.30) was investigated using ELF/VLF radio signal. The solar eclipse started at 05:30:04.4 hrs IST and lasted up to 07:27 hrs IST with totally from 6.25 IST to 6.27 IST.The changes in D-region ionospheric VLF reflection heights and electron density during eclipse have been estimated from tweek analysis. The reflection height increased from ~90 km from the first occurrence of tweek to about 93-94 km at the totality and then decreased to ~89 km at the end of the eclipse. The reflection heights are lower by 2-3 km as compared to the usual nighttime tweek reflection heights. The electron density is found to vary between 25-27 cm-3 at the reflection heights. The significant increase in tweek reflection height of about 15 km during the eclipse as compared to the daytime (morning) reflection heights of ~ 78 km is observed. Observations suggest that about 30-40% obscuration of solar disc can lead to the tweeks occurrence which otherwise occur only in the nighttime. A significant increase of 3dB in the strength of the amplitude of VLF signal is observed around the time of TSE as compared to a control day. These low latitude ionospheric perturbations on the eclipse day are discussed and compared with other normal days. During a solar eclipse, the decrease in solar flux due to moon's shadow causes sudden change in the D-region physical and chemical processes. During the totality due to blocking of Lyman-α 1215Å (major D-region ionizing radiation) by moon's umbral shadow, the electron density decreases drastically towards the nighttime values [Smith, 1972]. During the TSE, there was no production of ionization in the ionosphere and the ions and electrons in the lowest part of it recombined at a rapid rate resulting a depletion in the electron density in the 'D' region of the Ionosphere and hence an

  8. The Eddington Experiment during the 2017 Total Solar Eclipse Will Improve On Prior Work by Near Two Orders of Magnitude

    Science.gov (United States)

    Schaefer, Bradley E.

    2017-06-01

    The original Eddington experiment (measuring the gravitational bending of light for stars near a totally eclipsed Sun) in 1919 was one of the most famous and important experiments in all physics, becoming the iconic proof of Einstein's General Relativity (GR). The Eddington experiment has been run successfully for only 7 eclipses, last in 1973, never getting much better than ~10% measurement accuracy. Since then, precision tests of various predictions of GR have been big-time forefront physics, for example the recent discovery of gravitational waves with LIGO. The best measure of the gravitational bending of light comes from radio wavelengths with VLBI, where limits of 0.045% to 0.012% have been reported in the last decade.A modern version of the Eddington experiment can and should be run for the 21 August 2017 total solar eclipse, when we can improve on the historic results by orders of magnitude. This possibility of greatly improving the Eddington experiment has only just become feasible in the last few years, with the introduction of off-the-shelf CCD cameras with >4k pixels on a side. The near-optimal set of equipment is a 4-inch f/10 refractor with a 4096x4096 CCD all on a GOTO mount. With this, a 7-second image will record 101 unsaturated stars with angular distances from the center of the Sun from 41' to 86', each with centering accuracy of 0.06" to 0.25". A single exposure by itself will measure the gravitational bending of light to 2.3% accuracy. With Gaia positions, and many stars recorded over a large field, plus calibration images from the night sky, all known systematic errors will be much smaller than the final accuracy for any single observer. With many images during totality, one observer will measure the GR effect to an accuracy of 0.59%. With many observers, the accuracy will improve by a factor of the square root of the number of observers.On an independent track, a casual observer can now readily test Einstein's GR by better than anyone has done

  9. Investigation the effect of total solar eclipse March 9, 2016 on tidal elevation study cases: Bangka and Belitung islands

    Science.gov (United States)

    Radjawane, I. M.; Simanjuntak, E. M.; Adziima, A. F.; Sofian, I.

    2016-11-01

    Tidal elevation is generating primary by the gravitational forces between earth with moon and solar. Since the sun plays an important role on generating the tidal sea level then the effect of total solar eclipse (TSE) March 9, 2016 on surface water level has been analysed from real time one-minute tide gauge station from Geospatial Information Agency. Two stations was selected to observe the impact of TSE i.e. in coastal of Bangka Island where totally path of TSE was detected and the other is in the coastal Belitung Island, located near to Bangka Island. We compare the observed sea level with the predicted sea level from 9 constituents using Tidal Model Driver (TMD). The result shows that during the TSE in Bangka Island, the observed tidal phase is shifted and observed sea level is higher compare with the prediction one. But in Belitung Island, there is no pattern change of tidal phase and with small increasing sea level compare with the prediction.

  10. Absolute stellar parameters of KIC 09246715 -- a double-giant eclipsing system with a solar-like oscillator

    CERN Document Server

    Hełminiak, Krzysztof G; Kambe, Eiji; Konacki, Maciej

    2015-01-01

    We present our results of a combined analysis of radial velocity and light curves of a double-lined spectroscopic and eclipsing binary KIC 09246715, observed photometrically by the $Kepler$ satellite, and spectroscopically with the OAO-1.88m telescope with the HIgh-Dispertion Echelle Spectrograph (HIDES). The target was claimed to be composed of two red giants, one of which is showing solar-like oscillations. We have found that the mass and radius of the primary are $M_1=2.169\\pm0.024$ M$_\\odot$ and $R_1=8.47\\pm0.13$ R$_\\odot$, and of the secondary: $M_2=2.143\\pm0.025$ M$_\\odot$ and $R_2=8.18\\pm0.09$ R$_\\odot$, which confirms the double-giant status. Our secondary is the star to which the oscillations were attributed. Results of its previous asteroseismic analysis are in agreement with ours, only significantly less precise, but the subsequent light-curve-based study failed to derive correct mass and radius of our primary. KIC 09246715 is one of the rare cases where asteroseismic parameters of a solar-like osc...

  11. Using the IRI, the MAGIC model, and the co-located ground-based GPS receivers to study ionospheric solar eclipse and storm signatures on July 22, 2009

    Science.gov (United States)

    Lin, Chi-Yen; Liu, Jann-Yenq; Lin, Chien-Hung; Sun, Yang-Yi; Araujo-Pradere, Eduardo A.; Kakinami, Yoshihiro

    2012-06-01

    The longest total solar eclipse in the 21st century occurred in Southeast Asia on 22 July 2009 from 00:55 to 04:15 UT, and was accompanied by a moderate magnetic storm starting at 03:00 UT with a D st reduction of -78 nT at 07:00 UT. In this study, we use the ionospheric reference model IRI, the data assimilation model MAGIC, and ground-based GPS receivers to simulate and examine the ionospheric solar eclipse and geomagnetic storm signatures in Taiwan and Japan. Cross-comparisons between the two model results and observations show that IRI fails to simulate the two signatures while MAGIC partially reproduces the storm features. It is essential to include ground-based GPS measurements to improve the IRI performance.

  12. Crowdsourcing a Spatial Temporal Study of Low Frequency (LF) Propagation Effects Due to a Total Solar Eclipse: Engaging Students and Citizens in STEM

    Science.gov (United States)

    Lumsden, N. A.; Lukes, L.; Nelson, J.; Liles, W. C.; Kerby, K. C.; Crowov, F.; Rockway, J.

    2015-12-01

    The first experiments to study the effects of a solar eclipse on radio wave propagation were done in 1912 utilizing Low Frequency (LF; 30 - 300 kHz) radio waves at a handful of sites across Europe before any theory of the ionosphere had been confirmed and even before the word "ionosphere" existed. In the 1920s, a large cooperative experiment was promoted in the U.S. by Scientific American magazine. They collected over 2000 reports of AM broadcast stations from throughout the U.S. Unfortunately, many of the submissions were unusable because they lacked critical information such as date, time or location. We propose to use the 2017 solar eclipse over the continental U.S. to conduct the first wide-area LF propagation study. To perform this study, we plan to crowdsource the collection of the data by engaging student groups, citizens, and the scientific community. The tools for the different collection stations will consist of a simple homemade antenna, a simple receiver to convert the radio frequency (RF) signals to audio frequencies and a smart phone app. By using the time, date and location features of the smart phone, the problems experienced in the Scientific American experiment will be minimized. By crowdsourcing the observation sites, a number of different short, medium and long-paths studies can be obtained as the total eclipse crosses the continental U.S. The transmitter for this experiment will be WWVB located near Fort Collins, Colorado on 60.000 kHz. This is a U.S. frequency standard that is operated by NIST and transmits time codes. A second frequency, 55.500 kHz transmitted by a LF station in Dixon, CA is also being considered for this experiment. We will present an overall strategy for recruiting participants/crowdsourcing the RF collections during the 2017 total solar eclipse. Preliminary coverage calculations will be presented for WWVB and Dixon, as well as path loss calculations that can be expected during the solar eclipse condition. We will also

  13. Eclipses in Australian Aboriginal Astronomy

    CERN Document Server

    Hamacher, Duane W

    2011-01-01

    We explore 50 Australian Aboriginal accounts of lunar and solar eclipses to determine how Aboriginal groups understood this phenomenon. We summarise the literature on Aboriginal references to eclipses, showing that many Aboriginal groups viewed eclipses negatively, frequently associating them with bad omens, evil magic, disease, blood and death. In many communities, Elders or medicine men were believed to have the ability to control or avert eclipses by magical means, solidifying their role as provider and protector within the community. We also show that many Aboriginal groups understood the motions of the sun-earth-moon system, the connection between the lunar phases and tides, and acknowledged that solar eclipses were caused by the moon blocking the sun.

  14. Eclipses and the Olympics

    Science.gov (United States)

    Pang, K. D.; Yau, K. K.

    2000-12-01

    Like returns of Halley's comet the Olympic games occur periodically, though not as regularly in antiquity. Dates were also imprecise due to the chaotic calendars in use. Reported sightings of comets and eclipses can be used with game dates to help fix ancient events. However some reported darkening of the sun, e.g., after Julius Caesar's murder in 44 BC, was due to volcanic eruptions. A red comet, visible in daylight, first appeared during the games that year. It was also seen from China and Korea (Pang, Sciences 31, 30). Phlegon's ``Olympiads" (2nd century) says that Christ's crucifixion was in the 4th year of the 202nd Olympiad (AD 29-33), when a total solar eclipse occurred in the 6th hour. Only the Nov. 24, AD 29 eclipse over Asia Minor can match that, and Joel's prophecy (Acts 2, 14-21) that ``the sun will be turned to darkness and moon to blood." However it conflicts with ``the first day of Passover," as recorded by Mathew, Mark and Luke, i.e., full moon in early spring. Humphreys and Waddington (Nature 306, 743) have suggested meteorological darkening and the April 3, AD 33 lunar eclipse instead. Schaefer has questioned the eclipse's visibility from Jerusalem (31.46N, 35.14E). The six computations he cited gave dissimilar answers due to the imprecise rates of the secular lunar acceleration, and lengthening of the day used (Q.Jl.R.astr.Soc. 31, 53). Lunar laser ranging has since fixed the former at -26"/cen2. Analysis of ancient Chinese solar eclipse records, e.g., the April 21, 899 BC and April 4, AD 368 ``double dawns" over Zheng, has given us a delta T (in sec) = 30t2, where t is centuries before 1800 (Pang, Yau and Chou, in ``Dynamics of Ice Age Earth: A Modern Perspective," 1998). Our computations show that the moon rose over Jerusalem, with 1/3 still in the umbra and the rest in penumbra. Holdover meteorological darkening with long absorption air mass could have help reddened the moon also. Finally the first ``eclipse season" (the Aug. 21 lunar, and

  15. Hybrid nanocone forests with high absorption in full-solar spectrum for solar cell applications

    Science.gov (United States)

    Yang, Yudong; Mao, Haiyang; Xiong, Jijun; Ming, Anjie; Wang, Weibing

    2016-11-01

    In this work, hybrid nanocone forests (HNFs) with high absorption in full-solar-spectrum are fabricated based on a plasma repolymerization technique. The HNFs combine light trapping effect of the nanocone forests with surface plasmon resonance effect of the metallic nanoparticles, thus can achieve an optimized absorption larger than 80% in the full-solar spectrum (i.e. 200-2500nm). Besides, with the hybrid nanostructures, the absorption decrease around the Si bandgap width can be narrowed greatly, while the normalized utilization efficiency of solar radiation can be increased. Therefore, usage of the HNFs as a texture structure in solar cells to obtain higher conversion efficiencies is foreseeable.

  16. Review of Polymer, Dye-Sensitized, and Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    S. N. F. Mohd-Nasir

    2014-01-01

    Full Text Available The combination of inorganic nanoparticles semiconductor, conjugated polymer, and dye-sensitized in a layer of solar cell is now recognized as potential application in developing flexible, large area, and low cost photovoltaic devices. Several conjugated low bandgap polymers, dyes, and underlayer materials based on the previous studies are quoted in this paper, which can provide guidelines in designing low cost photovoltaic solar cells. All of these materials are designed to help harvest more sunlight in a wider range of the solar spectrum besides enhancing the rate of charge transfer in a device structure. This review focuses on developing solid-state dye-synthesized, polymer, and hybrid solar cells.

  17. 1927: a British eclipse

    Science.gov (United States)

    Marriott, R. A.

    1999-06-01

    The total solar eclipse of 1927 June 29 was the first to be seen over the British mainland for 203 years. It caused nationwide excitement, induced mass population movement to the towns, villages, moorlands and offshore waters of Wales and the north of England, and severely tested the country's transport and communication systems.

  18. The velocity of the dust near the Sun during the Solar Eclipse of March 29, 2006 and sungrazing comets

    CERN Document Server

    Shestakova, L I; Demchenko, B I; Rspaev, F K

    2010-01-01

    The measurements of the Doppler shifts of the Fraunhofer lines, scattered by the dust grains in the solar F-corona, provides the insight on the velocity field of the dust and hence on its origin. We report on such measurements obtained during the total eclipse of March 29, 2006. We used a Fabry-P\\'erot interferometer with the FOV of 5.9 degrees and the spectral resolution of about 5000 to record Fraunhofer spectral lines scattered by the dust of the F-Corona. The spectral region was centered on the MgI 5172.69 A line. The measured line-on-sight velocities with the amplitude in the range from -10 to 10 km/s show that during our observations the dust grains were on the orbit with a retrograde motion in a plane nearly perpendicular to the ecliptics. This indicates their cometary origin. Indeed, at the end of March, 2006, SOHO recorded several sungrazing comets with the orbital elements close to what was deduced from our measurements. We conclude that the contribution of comets to the dust content in the region c...

  19. Measuring the level of public understanding of total solar eclipse from the mass media: Palembang as sample

    Science.gov (United States)

    Purwati, F. G.; Ekawanti, N.; Luthfiandari; Premadi, P. W.

    2016-11-01

    The Total Solar Eclipse (TSE) on the 9th March 2016 received a huge attention from the mass media. Some of them intensively write articles about it even months before the TSE day. As we know media plays strategic role not only in raising public awareness but also interest. The aim of this project is to study the relation between the number of accesses to the media information and how well public learned the information delivered by the media. We prepared questionnaire consisting of seven semi-multiple choices on how public got information about TSE. We gave them choices of what they had heard to measure their basic understanding of TSE. Furthermore we add two “wrong” choices in the last questions to identify less serious respondents. We analyze 60 respondents of Palembang who visited Ampera bridge area. Our result shows no correlation between the number of information access and the level of understanding about TSE. We also found that local media did not provide the scientific content of TSE as well as the national media.

  20. Absolute dimensions of solar-type eclipsing binaries. EF Aquarii: a G0 test for stellar evolution models

    CERN Document Server

    Vos, J; Jørgensen, U G; Østensen, R H; Claret, A; Hillen, M; Exter, K

    2012-01-01

    Recent studies have shown that stellar chromospheric activity, and its effect on convective energy transport in the envelope, is most likely the cause of significant radius and temperature discrepancies between theoretical evolution models and observations. We aim to determine absolute dimensions and abundances for the solar-type detached eclipsing binary EF Aqr, and to perform a detailed comparison with results from recent stellar evolutionary models. uvby-beta standard photometry was obtained with the Stromgren Automatic Telescope. The broadening function formalism was applied on spectra observed with HERMES at the Mercator telescope in La Palma, to obtain radial velocity curves. Masses and radii with a precision of 0.6% and 1.0% respectively have been established for both components of EF Aqr. The active 0.956 M_sol secondary shows star spots and strong Ca II H and K emission lines. The 1.224 M_sol primary shows signs of activity as well, but at a lower level. An [Fe/H] abundance of 0.00+-0.10 is derived w...

  1. Eclipse Imagery in Mexica Sculpture of Central Mexico

    Science.gov (United States)

    Milbrath, S.

    Major monuments of the Mexica (Aztec) style are analyzed in terms of possible eclipse imagery. The cycle of monuments linked to the Coyolxauhqui myth are recognized as possible images of historical lunar eclipses. The Bilimek vessel is identified with an historical solar eclipse in 1508. The Calendar Stone is recognized as an image of world cataclysm that may refer to a solar eclipse at the end of the world. In addition, the codices are studied in terms of visual images of eclipses and a pattern linking solar eclipses to the death of a ruler.

  2. A stamped PEDOT:PSS-silicon nanowire hybrid solar cell.

    Science.gov (United States)

    Moiz, Syed Abdul; Nahhas, Ahmed Muhammad; Um, Han-Don; Jee, Sang-Won; Cho, Hyung Koun; Kim, Sang-Woo; Lee, Jung-Ho

    2012-04-13

    A novel stamped hybrid solar cell was proposed using the stamping transfer technique by stamping an active PEDOT:PSS thin layer onto the top of silicon nanowires (SiNWs). Compared to a bulk-type counterpart that fully embeds SiNWs inside PEDOT:PSS, an increase in the photovoltaic efficiency was observed by a factor of ∼4.6, along with improvements in both electrical and optical responses for the stamped hybrid cell. Such improvements for hybrid cells was due to the formation of well-connected and linearly aligned active PEDOT:PSS channels at the top ends of the nanowires after the stamping process. These stamped channels facilitated not only to improve the charge transport, light absorption, but also to decrease the free carriers as well as exciton recombination losses for stamped hybrid solar cells.

  3. Solar corona during the total solar eclipse of 2009. (Czech Title: Sluneční koróna během zatmění Slunce v roce 2009)

    Science.gov (United States)

    Marková, E.; Bělík, M.; Křivský, L.; Druckmüller, M.

    2010-12-01

    This work is focused on primary processing of the solar eclipse observations of July 22, 2009. As part of the "Shadow-tracking expedition" project several expeditions were organized to observe the phenomenon. Unfortunately, bad weather conditions prevented a successful observation in the China region. Pre-processing was carried out from images taken at Envetak Atoll in Marshall Islands. From the isophot evolution a corona flattening was found, and from the processed fine structure images a parameter called "source area radius", used mainly for calculations in models of the coronal magnetic fields, was determined. Both of these parameters supplement the data obtained during the previous eclipses, and the first conclusions on the state of the corona during an eclipse are deduced.

  4. Fine Structure in the Circumstellar Environment of a Young, Solar-like Star the Unique Eclipses of KH 15D

    CERN Document Server

    Herbst, W; Vrba, F J; Ibrahimov, M A; Bailer-Jones, C A L; Mundt, R; Lamm, M J; Mazeh, T; Webster, Z T; Haisch, K E; Williams, E C; Rhodes, A H; Balonek, T J; Riffeser, A; Herbst, William; Hamilton, Catrina M.; Vrba, Frederick J.; Ibrahimov, Mansur A.; Bailer-Jones, Coryn A.L.; Mundt, Reinhard; Lamm, Markus; Mazeh, Tsevi; Webster, Zodiac T.; Haisch, Karl E.; Williams, Eric C.; Rhodes, Andrew H.; Balonek, Thomas J.; Riffeser, Alexander Scholz and Arno

    2002-01-01

    Results of an international campaign to photometrically monitor the unique pre-main sequence eclipsing object KH 15D are reported. An updated ephemeris for the eclipse is derived that incorporates a slightly revised period of 48.36 d. There is some evidence that the orbital period is actually twice that value, with two eclipses occurring per cycle. The extraordinary depth (~3.5 mag) and duration (~18 days) of the eclipse indicate that it is caused by circumstellar matter, presumably the inner portion of a disk. The eclipse has continued to lengthen with time and the central brightness reversals are not as extreme as they once were. V-R and V-I colors indicate that the system is slightly bluer near minimum light. Ingress and egress are remarkably well modeled by the passage of a knife-edge across a limb-darkened star. Possible models for the system are briefly discussed.

  5. Thermal analysis of solar biomass hybrid co-generation plants

    Science.gov (United States)

    Kaushika, N. D.; Mishra, Anuradha; Chakravarty, M. N.

    2005-12-01

    This article describes a co-generation plant based on the biogas being produced from the waste of distillery plant and highlights the possible configuration in which the plant can be hybridized with auxiliary solar energy source having the advantage of using financial incentives in several countries. In hybridization, the solar heat is used for heating the boiler feed water. The solar heat-generating unit consists of line focus parabolic trough collector, heat transportation system and heat delivery unit such as heat exchanger. The simulation model of heat and mass transfer processes in the solar field as well as the balance of the system is developed to investigate the technological feasibility of the concept in terms of plant yield and matching of subsystems.

  6. Benefits of solar/fossil hybrid gas turbine systems

    Science.gov (United States)

    Bloomfield, H. S.

    1979-01-01

    The potential benefits of solar/fossil hybrid gas turbine power systems were assessed. Both retrofit and new systems were considered from the aspects of cost of electricity, fuel conservation, operational mode, technology requirements, and fuels flexibility. Hybrid retrofit (repowering) of existing combustion (simple Brayton cycle) turbines can provide near-term fuel savings and solar experience, while new and advanced recuperated or combined cycle systems may be an attractive fuel saving and economically competitive vehicle to transition from today's gas and oil-fired powerplants to other more abundant fuels.

  7. Solar central receiver hybrid - A cost effective future power alternative

    Science.gov (United States)

    Beshore, D. G.; Bolton, C. N.; Montague, J. E.

    1980-05-01

    System analyses and conceptual designs of solar central receiver hybrid concepts using molten salt (60% NaNO3, 40% KNO3 by weight) and fossil fired nonsolar energy sources (coal, oil, or gas) have been performed. Analyses have developed plant configurations with various solar energy storage capacities and fossil fuels. Economic analyses support the final configuration selection based on minimization of the cost of energy produced from the plant. A 500 MWe commercial plant size installed for a 1990 initial year of operation is competitive with new coal, oil, and nuclear power generation sources. This hybrid plant will save an estimated 5 million barrels of oil per year.

  8. The solar and lunar eclipse records in the Southern and Northern Dynasties%南北朝日月食记录

    Institute of Scientific and Technical Information of China (English)

    刘次沅; 马莉萍

    2013-01-01

    梳理南北朝时期天象记录的文献来源,对这一时期的日食、月食记录进行全面的搜集、勘误和统计分析.研究了这些记录的文献来源、时间分布、覆盖率和记录特征.南朝正确记录日食25条,占实际发生的40%;月食正确记录23条,占实际发生的14%;北朝日食51条,占65%,月食56条,占29%.%Literature source of astronomical records in the Northern and Southern Dynasties are reorganized; the solar and lunar eclipse records during the period are collected,examined,amended and statistically analyzed.A range of parameters including sources of literature,time distribution,cover rate and feature of records are analyzed.For the Southern Dynasties,there were 25 accurate records of solar eclipse,accounting for 40% of what actually happened; the figures are 23 and 14% of lunar eclipse.For the Northern Dynasties,the figures are 51 and 65%,and 56 and 29%,respectively.

  9. The possibility of developing hybrid PV/T solar system

    Science.gov (United States)

    Dobrnjac, M.; Zivkovic, P.; Babic, V.

    2017-05-01

    An alternative and cost-effective solution to developing integrated PV system is to use hybrid photovoltaic/thermal (PV/T) solar system. The temperature of PV modules increases due to the absorbed solar radiation that is not converted into electricity, causing a decrease in their efficiency. In hybrid PV/T solar systems the reduction of PV module temperature can be combined with a useful fluid heating. In this paper we present the possibility of developing a new hybrid PV/T solar system. Hybrid PV/T system can provide electrical and thermal energy, thus achieving a higher energy conversion rate of the absorbed solar radiation. We developed PV/T prototype consisted of commercial PV module and thermal panel with our original solution of aluminium absorber with special geometric shapes. The main advantages of our combined PV/T system are: removing of heat from the PV panel; extending the lifetime of photovoltaic cells; excess of the removing heat from PV part is used to heat the fluid in the thermal part of the panel; the possibility of using on the roof and facade constructions because less weight.

  10. VLF Perturbations Associated with Solar Eclipses of November 2012 and may 2013 IN the South Pacific Region

    Science.gov (United States)

    Kumar, S.; Kumar, A.

    2015-12-01

    Sub-ionospheric VLF signals from the NWC (19.8 kHz), NPM (21.4 kHz) and NLK (24.8 kHz) MSK VLF transmitters are monitored at Suva, Fiji, with a time resolution of 0.1s using GPS based timing and SoftPAL VLF system. Here one minute averaged amplitude and phase data have been used for analysis. We present perturbations in VLF propagation and D-region changes associated with 13 November 2012 total solar eclipse (SE) and 9-10 May 2013 annular SE using VLF observations at Suva, Fiji. During 13-14 November 2012 total SE, the totality shadow intercepted NWC-Suva path and NWC signal amplitude and phase decreased by about 0.70 dB and 23°, respectively. NPM signal amplitude during 9-10 May 2013 SE decreased by about 2.0 dB. The amplitude perturbation of ~1.8 dB on NLK signal was measured from the unperturbed level associated with 9-10 May 2013 SE. The decrease in the amplitude at the site can be understood in terms of destructive interference of modes converted at the discontinuity created by the eclipse intercepting the different Transmitter-receiver great circle paths (TRGCPs) and changes in the propagation conditions along TRGCPs. The decrease in the amplitude and phase of NWC signal for 13-14 November 2012 SE has been modeled using Long Wave Propagation Capability code to estimate the changes in D-region reflection height (H') and sharpness factor (β) which shows that H' and β were increased by 0.95 km and 0.01 km-1, respectively. The phase changes on NWC signal associated with 9-10 May 2013 SE have been used to estimate the recombination coefficient value, for 75 km height where electron density reduction due to SE was about 40%. The changes in the D-region parameters and the electron density are due to sudden decrease of the photo-ionization creating nighttime like conditions in the D-region ionosphere.

  11. Fresnel-collectors in hybrid solar thermal power plants with high solar shares

    Energy Technology Data Exchange (ETDEWEB)

    Lerchenmueller, H.; Mertins, M.; Morin, G. [Fraunhofer Inst. for Solar Energy Systems, Freiburg (Germany); Haeberle, A. [PSE GmbH, Solar Info Center, Freiburg (Germany); Bockamp, S.; Ewert, M.; Fruth, M.; Griestop, T. [E.ON Energie AG, Muenchen (Germany); Dersch, J. [Deutsches Zentrum fuer Luft- und Raumfahrt, Koeln (Germany)

    2004-07-01

    The use of Fresnel-Collectors in power plant configurations with low or zero CO2-emission has been analysed in this paper. Both, the solar-biomass hybrid plant and the solar-gas hybrid plant are very promising concepts with respect to technical, economical and ecological aspects. The hybrid operation would be very useful to handle the fluctuating solar resource and facilitate operation. Depending on feed in tariffs the hybridisation of a solar thermal power plant with biomass or with small shares of natural gas can be economically very interesting. The ecological advantage of a solar-biomass power plant is evident, since it would be a zero CO2- emission plant. Beyond that biomass is a limited source, especially in regions with high solar irradiance. The herein examined gas hybrid variants are by far more favourable than Integrated Solar Combined Cycle Systems (ISCCS), which have been previously examined. Since much higher solar shares can be reached this is a forward-looking technology. Furthermore the solar field does not act as a disturbing factor as opposed to the ISCCS concept, where the efficiency of the sophisticated CC system is reduced due to suboptimal dimensioning of components. In other words: It is better to build the suggested hybrid plant with low gas share and CC plants instead of ISCCS plants. The resulting solar levelised electricity costs of both options are approximately the same. The calculated levelised electricity costs for the examined configurations of between 11 and 13 ct/kWh are very promising results. The calculations were made based on cost assumptions for the collector of 130 Euro/m{sup 2} which seems realistic not for the first project but for the third plant. As a next step in the commercialisation of the Fresnel-technology demonstration and test collectors must be built, such as by the Australian company Solar Heat and Power, to validate the technical and economic assumptions. (orig.)

  12. Solar Eclipse: The rise and "dusk" of the Dutch PV Innovation System

    NARCIS (Netherlands)

    Negro, S.O.; Vasseur, V.; Sark, W.G.J.H.M. van; Hekkert, M.P.

    2012-01-01

    In this paper, we take the theoretical perspective of innovation system dynamics and apply this to Photovoltaic (PV) solar energy technology in the Netherlands. The history of the development of the PV innovation system is analysed in terms of seven key processes that are essential for the build-up

  13. Solar Cooling System Using Solar-Driven Hybrid Chiller

    OpenAIRE

    Hirai, Akira

    2012-01-01

    We developed an appropriate Absorption chiller to "Solar cooling system" in 2010. In addition, we added the improvement to the machine. "Solar cooling system" can be easily constructed with the machine. and, we constructed the demonstration plant, and verified the utility

  14. Symbolism and discovery: eclipses in art.

    Science.gov (United States)

    Blatchford, Ian

    2016-09-28

    There is a fascinating tradition of depicting solar eclipses in Western art, although these representations have changed over time. Eclipses have often been an important feature of Christian iconography, but valued as much for their biblical significance as for the splendour of the physical event. However, as Western culture passed through the Renaissance and Enlightenment the depictions of eclipses came to reflect new astronomical knowledge and a thirst for rational learning well beyond the confines of the church and other elites. Artists also played a surprisingly important role in helping scientists in the nineteenth century understand and record the full phenomena of an eclipse, even as the advent of photography also came to solve a number of scientific puzzles. In the most recent century, artists have responded to eclipses with symbolism, abstraction and playfulness.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  15. Technical and economic assessment of solar hybrid repowering. Final report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-09-01

    Public Service Company of New Mexico (PNM) has performed a Technical and Economic Assessment of Solar Hybrid Repowering under funding by the Department of Energy (DOE), the Electric Power Research Institute (EPRI), Western Energy Supply and Transmission (WEST) Associates, and a number of southwestern utilities. Solar hybrid repowering involves placement of solar hardware adjacent to and connected to existing gas- and oil-fueled electric generation units to displace some of or all the fossil fuel normally used during daylight hours. The subject study assesses the technical economic viability of the solar hybrid repowering concept within the southwestern United States and the PNM system. This document is a final report on the study and its results. The study was divided into the six primary tasks to allow a systematic investigation of the concept: (1) market survey and cost/benefit analysis, (2) study unit selection, (3) conceptual design and cost estimates, (4) unit economic analysis, (5) program planning, future phases, and (6) program management. Reeves Station No. 2 at Albuquerque, New Mexico, was selected for repowering with a design goal of 50 percent (25 MWe). The solar system design is based on the 10 MW solar central receiver pilot plant preliminary design for Barstow, California. SAN--1608-4-2 contains the technical drawings. (WHK)

  16. Coronal temperature profiles obtained from kinetic models and from coronal brightness measurements obtained during solar eclipses

    CERN Document Server

    Pierrard, V; Lemaire, J F

    2012-01-01

    Coronal density, temperature and heat flux distributions for the equatorial and polar corona have been deduced by Lemaire [2012] from Saito's model of averaged coronal white light (WL) brightness and polarization observations. They are compared with those determined from a kinetic collisionless/exospheric model of the solar corona. This comparison indicates rather similar distributions at large radial distances (> 7 Rs) in the collisionless region. However, rather important differences are found close to the Sun in the acceleration region of the solar wind. The exospheric heat flux is directed away from the Sun, while that inferred from all WL coronal observations is in the opposite direction, i.e., conducting heat from the inner corona toward the chromosphere. This could indicate that the source of coronal heating rate extends up into the inner corona where it maximizes at r > 1.5 Rs well above the transition region.

  17. Countdown to the Great American Eclipse

    Science.gov (United States)

    Fulco, Charles

    2017-01-01

    The Great American Total Solar Eclipse (TSE2017) will occur on August 21 this year--the first total solar eclipse in the continental United States since 1979. For many reasons, this is a scientific and educational milestone event of the highest magnitude that should not be missed by any teacher and student whether or not their school is in session…

  18. Passive and Hybrid Solar Energy Program

    Energy Technology Data Exchange (ETDEWEB)

    1980-11-01

    The background and scope of the program is presented in general terms. The Program Plan is summarized describing how individual projects are categorized into mission-oriented tasks according to market sector categories. The individual projects funded by DOE are presented as follows: residential buildings, commercial buildings, solar products, solar cities and towns, and agricultural buildings. A summary list of projects by institution (contractors) and indexed by market application area is included. (MHR)

  19. Long term changes in EUV and X-ray emissions from the solar corona and chromosphere as measured by the response of the Earth’s ionosphere during total solar eclipses from 1932 to 1999

    Directory of Open Access Journals (Sweden)

    C. J. Davis

    Full Text Available Measurements of the ionospheric E region during total solar eclipses in the period 1932–1999 have been used to investigate the fraction of Extreme Ultra Violet and soft X-ray radiation, 8, that is emitted from the limb corona and chromosphere. The relative apparent sizes of the Moon and the Sun are different for each eclipse, and techniques are presented which correct the measurements and, therefore, allow direct comparisons between different eclipses. The results show that the fraction of ionising radiation emitted by the limb corona has a clear solar cycle variation and that the underlying trend shows this fraction has been increasing since 1932. Data from the SOHO spacecraft are used to study the effects of short-term variability and it is shown that the observed long-term rise in 8 has a negligible probability of being a chance occurrence.

    Key words. Ionosphere (solar radiation and cosmic ray effects – Solar physics, astrophysics, and astronomy (corona and transition region

  20. A hybrid reconfigurable solar and wind energy system

    Science.gov (United States)

    Gadkari, Sagar A.

    We study the feasibility of a novel hybrid solar-wind hybrid system that shares most of its infrastructure and components. During periods of clear sunny days the system will generate electricity from the sun using a parabolic concentrator. The concentrator is formed by individual mirror elements and focuses the light onto high intensity vertical multi-junction (VMJ) cells. During periods of high wind speeds and at night, the same concentrator setup will be reconfigured to channel the wind into a wind turbine which will be used to harness wind energy. In this study we report on the feasibility of this type of solar/wind hybrid energy system. The key mechanisms; optics, cooling mechanism of VMJ cells and air flow through the system were investigated using simulation tools. The results from these simulations, along with a simple economic analysis giving the levelized cost of energy for such a system are presented. An iterative method of design refinement based on the simulation results was used to work towards a prototype design. The levelized cost of the system achieved in the economic analysis shows the system to be a good alternative for a grid isolated site and could be used as a standalone system in regions of lower demand. The new approach to solar wind hybrid system reported herein will pave way for newer generation of hybrid systems that share common infrastructure in addition to the storage and distribution of energy.

  1. Solar eclipse. The rise and 'dusk' of the Dutch PV innovation system

    Energy Technology Data Exchange (ETDEWEB)

    Negro, S.O.; Hekkert, M.P. [Department of Innovation Studies, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands); Vasseur, V. [International Centre for Integrated Assessment and Sustainable Development, University Maastricht, P.O. Box 616, 6200 MD Maastricht (Netherlands); Van Sark, W.G.J.H.M. [Department of Science, Technology and Society, Copernicus Institute for Sustainable Development and Innovation, Utrecht University, Heidelberglaan 2, 3584 CS Utrecht (Netherlands)

    2012-07-01

    In this paper, we take the theoretical perspective of innovation system dynamics and apply this to Photovoltaic (PV) solar energy technology in the Netherlands. The history of the development of the PV innovation system is analysed in terms of seven key processes that are essential for the build-up of innovation systems. We show that large fluctuations are present in the processes related to guidance of the search and market formation. Surprisingly, entrepreneurial activities are not too much affected by fluctuating market formation activities. We relate this to market formation in neighbouring countries and discuss the implications for policy making.

  2. Hybrid Solar: A Review on Photovoltaic and Thermal Power Integration

    Directory of Open Access Journals (Sweden)

    T. T. Chow

    2012-01-01

    Full Text Available The market of solar thermal and photovoltaic electricity generation is growing rapidly. New ideas on hybrid solar technology evolve for a wide range of applications, such as in buildings, processing plants, and agriculture. In the building sector in particular, the limited building space for the accommodation of solar devices has driven a demand on the use of hybrid solar technology for the multigeneration of active power and/or passive solar devices. The importance is escalating with the worldwide trend on the development of low-carbon/zero-energy buildings. Hybrid photovoltaic/thermal (PVT collector systems had been studied theoretically, numerically, and experimentally in depth in the past decades. Together with alternative means, a range of innovative products and systems has been put forward. The final success of the integrative technologies relies on the coexistence of robust product design/construction and reliable system operation/maintenance in the long run to satisfy the user needs. This paper gives a broad review on the published academic works, with an emphasis placed on the research and development activities in the last decade.

  3. Graphene-based transparent electrodes for hybrid solar cells

    Directory of Open Access Journals (Sweden)

    Pengfei eLi

    2014-11-01

    Full Text Available The graphene-based transparent and conductive films were demonstrated to be cost-effective electrodes working in organic-inorganic hybrid Schottky solar cells. Large area graphene films were produced by chemical vapor deposition (CVD on copper foils and transferred onto glass as transparent electrodes. The hybrid solar cell devices consist of solution processed poly (3, 4-ethlenedioxythiophene: poly (styrenesulfonate (PEDOT: PSS which is sandwiched between silicon wafer and graphene electrode. The solar cells based on graphene electrodes, especially those doped with HNO3, has comparable performance to the reference devices using commercial indium tin oxide (ITO. Our work suggests that graphene-based transparent electrode is a promising candidate to replace ITO.

  4. Atmospheric Effects of the Total Solar Eclipse of 4 December 2002 Simulated with a High-Altitude Global Model

    Science.gov (United States)

    2007-07-25

    temperature decreases and associated meridional wind changes in the lower mesosphere during eclipses [Ballard et al., 1969; Quiroz and Henry, 1973...atmosphere have reported temperature decreases in the 5–12 K range at 50–60 km altitude during eclipse passages [Ballard et al., 1969; Quiroz and...Henry, 1973; Randhawa, 1974; Schmidlin and Olsen, 1984]. Quiroz and Henry [1973] and Schmidlin and Olsen [1984] also reported substantial increases in

  5. Ultralight Solar Powered Hybrid Research Drone

    CERN Document Server

    Singer, Csaba

    2013-01-01

    A planetary research drone is proposed, which is capable for vertical takeoff and landing. A hybrid flight concept utilizing static lift enables the exploration over ground. The static lift is achieved with a lighter than CO2 gas like air, He or H2.

  6. Structure, Dynamics, and Spectra of the Solar Corona at the 2013 and 2015 Total Eclipses and Plans for 2017's American Totality

    Science.gov (United States)

    Pasachoff, Jay M.; Dantowitz, Ronald; Voulgaris, Aristeidis

    2016-01-01

    We observed the total solar eclipses of 3 November 2013 from Gabon and of 20 March 2015 from Svalbard in clear skies with cameras to image the solar corona at high resolution and with spectrographs for coronal emission lines. We report on the composite images showing coronal structure and (in comparison with other sites' images) dynamics, as well as the relation of our inner- and middle-corona composite images with surface EUV images from SDO and SWAP and with the outer-corona images from the coronagraphs on SOHO/LASCO. Our spectra show not only the common forbidden lines of Fe XIV (green line) and Fe X (red line) but also rarer species such as Ca XV. Finally, we describe our planned suite of observations for the 21 August 2017 solar eclipse, whose path of totality will cross the United States from Pacific to Atlantic, with more-favorable cloudiness statistics for western sites.Our Gabon and Svalbard expeditions were supported by grants from the Committee for Research and Exploration of the National Geographic Society.

  7. News and Views: A total solar eclipse over Rapa Nui; ESA's vision; International team wins first Ambartsumian Prize; Thinner thermosphere; ESA funds games; Team finds starspots

    Science.gov (United States)

    2010-10-01

    Francisco Diego recorded spectacular images of the 11 July 2010 total solar eclipse from Rapa Nui (Easter Island), making the most of modern digital technology - much of which originated from astronomical research - in taking and processing the images. The European Space Agency has set out its priorities for the decade starting in 2015, in a report entitled Cosmic Vision. The first Viktor Ambartsumian International Prize, in memory of the distinguished Armenian theorist, goes to the team led by Prof. Michel Mayor of the Observatory of Geneva, for ``their important contribution in the study of relation between planetary systems and their host stars''.

  8. 2009年一次日食过程对气象信息传输影响的分析%Study on the Influence of a Solar Eclipse on the Meteorological Information Transmission in 2009

    Institute of Scientific and Technical Information of China (English)

    李郓; 王军海; 熊承伟; 李在海

    2012-01-01

    2009年我国境内发生一次大范围日食过程,针对日全食和日偏食地区9个台站气象信息传输系统的工作状态和资料接收情况进行了统计,分析表明日食对气象信息传输无明显影响。%A solar eclipse phenomenon occurred in 2009 over many regions in our country. The running states and data receiving process in the satellite networks,CCTV system,VSAT system and Geostationary Meteorological Satel- lite imagery receiving system are statistically analyzed in nine units over the regions, where the total solar eclipse and partial solar eclipse occurred. Several useful conclusions are drawn from the laws summarized.

  9. Solar Field Optical Characterization at Stillwater Geothermal/Solar Hybrid Plant

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Guangdong [National Renewable Energy Laboratory,15013 Denver West Parkway,Golden, CO 80401e-mail: Guangdong.Zhu@nrel.gov; Turchi, Craig [National Renewable Energy Laboratory,15013 Denver West Parkway,Golden, CO 80401

    2017-01-27

    Concentrating solar power (CSP) can provide additional thermal energy to boost geothermal plant power generation. For a newly constructed solar field at a geothermal power plant site, it is critical to properly characterize its performance so that the prediction of thermal power generation can be derived to develop an optimum operating strategy for a hybrid system. In the past, laboratory characterization of a solar collector has often extended into the solar field performance model and has been used to predict the actual solar field performance, disregarding realistic impacting factors. In this work, an extensive measurement on mirror slope error and receiver position error has been performed in the field by using the optical characterization tool called Distant Observer (DO). Combining a solar reflectance sampling procedure, a newly developed solar characterization program called FirstOPTIC and public software for annual performance modeling called System Advisor Model (SAM), a comprehensive solar field optical characterization has been conducted, thus allowing for an informed prediction of solar field annual performance. The paper illustrates this detailed solar field optical characterization procedure and demonstrates how the results help to quantify an appropriate tracking-correction strategy to improve solar field performance. In particular, it is found that an appropriate tracking-offset algorithm can improve the solar field performance by about 15%. The work here provides a valuable reference for the growing CSP industry.

  10. Mediciones de irradiancia solar y capa de ozono durante el eclipse de Sol de 1994 en el Observatorio Astronómico de Rosario, Argentina

    Science.gov (United States)

    Piacentini, R. D.; Micheletti, M. I.

    We show results of measurements made during the Sun's eclipse of November 3, 1994, in Observatorio Astronómico de Rosario (32o 57' S, 60o 37' W, 25 m a.s.l.). The eclipse begin at 8:41 local hour, reached its maximum with 77% of the surface covered at 9:51 and finished at 11:04. The direct solar irradiance of 300 nm and 313 nm were able to be measured, due to the fact that during the whole period the sky remained completed uncovered (zero percent cloudiness). The measurements were made with the portable ozonometer developed by Tocho and co-workers. They show the characterictic decrease due to the occultation of the source, which is approximately proportional to the surface's diminution. When crossing the earth's atmosphere to arrive to the observation point, these irradiances are affected mainly by the ozone layer, specially the irradiance at lower wavelength, what let it to determine by comparison the thickness of this layer. The total ozone thickness distributed between the troposphere and the stratosphere shows an oscillation, whose amplitude, since the occurence of the maximum of occulation, has a mean value of 4%, and whose period is of approximately 2100 seconds, being both numbers considerably larger than the ones registred by Mims III y Mims (Geophysical Research Letters, 20, 367, 1993) during the eclipse of July 11, 1991 and by Tocho, Da Silva y Rivas (XVIII Quadriennial Ozone Symposiom, Italy, September, 1996) during the same eclipse analyzed in the present work, but observed in Salta. As complementary results, we measured the global irradiance and the ambient temperature during this astronomical event.

  11. A Review of Hybrid Solar PV and Wind Energy System

    Directory of Open Access Journals (Sweden)

    Rashid Al Badwawi

    2015-07-01

    Full Text Available Due to the fact that solar and wind power is intermittent and unpredictable in nature, higher penetration of their types in existing power system could cause and create high technical challenges especially to weak grids or stand-alone systems without proper and enough storage capacity. By integrating the two renewable resources into an optimum combination, the impact of the variable nature of solar and wind resources can be partially resolved and the overall system becomes more reliable and economical to run. This paper provides a review of challenges and opportunities / solutions of hybrid solar PV and wind energy integration systems. Voltage and frequency fluctuation, and harmonics are major power quality issues for both grid-connected and stand-alone systems with bigger impact in case of weak grid. This can be resolved to a large extent by having proper design, advanced fast response control facilities, and good optimization of the hybrid systems. The paper gives a review of the main research work reported in the literature with regard to optimal sizing design, power electronics topologies and control. The paper presents a review of the state of the art of both grid-connected and stand-alone hybrid solar and wind systems.

  12. Analysis of advanced solar hybrid desiccant cooling systems for buildings

    Energy Technology Data Exchange (ETDEWEB)

    Schlepp, D.; Schultz, K.

    1984-10-01

    This report describes an assessment of the energy savings possible from developing hybrid desiccant/vapor-compression air conditioning systems. Recent advances in dehumidifier design for solar desiccant cooling systems have resulted in a dehumidifier with a low pressure drop and high efficiency in heat and mass transfer. A recent study on hybrid desiccant/vapor compression systems showed a 30%-80% savings in resource energy when compared with the best conventional systems with vapor compression. A system consisting of a dehumidifier with vapor compression subsystems in series was found to be the simplest and best overall performer.

  13. Meteorological effects of the solar eclipse of 20 March 2015: analysis of UK Met Office automatic weather station data and comparison with automatic weather station data from the Faroes and Iceland.

    Science.gov (United States)

    Hanna, Edward; Penman, John; Jónsson, Trausti; Bigg, Grant R; Björnsson, Halldór; Sjúrðarson, Sølvi; Hansen, Mads A; Cappelen, John; Bryant, Robert G

    2016-09-28

    Here, we analyse high-frequency (1 min) surface air temperature, mean sea-level pressure (MSLP), wind speed and direction and cloud-cover data acquired during the solar eclipse of 20 March 2015 from 76 UK Met Office weather stations, and compare the results with those from 30 weather stations in the Faroe Islands and 148 stations in Iceland. There was a statistically significant mean UK temperature drop of 0.83±0.63°C, which occurred over 39 min on average, and the minimum temperature lagged the peak of the eclipse by about 10 min. For a subset of 14 (16) relatively clear (cloudy) stations, the mean temperature drop was 0.91±0.78 (0.31±0.40)°C but the mean temperature drops for relatively calm and windy stations were almost identical. Mean wind speed dropped significantly by 9% on average during the first half of the eclipse. There was no discernible effect of the eclipse on the wind-direction or MSLP time series, and therefore we can discount any localized eclipse cyclone effect over Britain during this event. Similar changes in air temperature and wind speed are observed for Iceland, where conditions were generally clearer, but here too there was no evidence of an eclipse cyclone; in the Faroes, there was a much more muted meteorological signature.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'.

  14. Nanocomposite-Based Bulk Heterojunction Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Bich Phuong Nguyen

    2014-01-01

    Full Text Available Photovoltaic devices based on nanocomposites composed of conjugated polymers and inorganic nanocrystals show promise for the fabrication of low-cost third-generation thin film photovoltaics. In theory, hybrid solar cells can combine the advantages of the two classes of materials to potentially provide high power conversion efficiencies of up to 10%; however, certain limitations on the current within a hybrid solar cell must be overcome. Current limitations arise from incompatibilities among the various intradevice interfaces and the uncontrolled aggregation of nanocrystals during the step in which the nanocrystals are mixed into the polymer matrix. Both effects can lead to charge transfer and transport inefficiencies. This paper highlights potential strategies for resolving these obstacles and presents an outlook on the future directions of this field.

  15. Wind Solar Hybrid System Rectifier Stage Topology Simulation

    Directory of Open Access Journals (Sweden)

    Anup M. Gakare

    2014-06-01

    Full Text Available This paper presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. The hybrid system allows maximum utilization of freely available renewable sources like wind and photovoltaic energies. This paper presents a new system configuration of the multi input rectifier stage for a hybrid wind and photovoltaic energy system. This configuration allows the two sources to supply the load simultaneously depending on the availability of the energy sources maximum power from the sun when it is available. An adaptive MPPT algorithm with a standard perturbs and observed method will be used for the Photo Voltaic system. The main advantage of the hybrid system is to give continuous power supply to the load. The gating pulses to the inverter switches are implemented with conventional and fuzzy controller. This hybrid wind-photo voltaic system is modeled in MATLAB/ SIMULINK environment. Simulation circuit is analyzed and results are presented for this hybrid wind and solar energy system.

  16. Low cost, efficient hybrid solar cells

    OpenAIRE

    Malinkiewicz, Olga

    2017-01-01

    Actualmente, existen diversas estrategias para producir energía limpia mediante fuentes renovables, pero es la explotación directa de la energía del Sol la que se presenta como una solución ideal, siendo la mayor fuente de energía verde en la Tierra. La potencia de la energía solar que llega a la Tierra cada año es del orden de 86000 TW (Terawatt, 1012 Watt). Esto representa 4800 veces la demanda energética anual del mundo, estimada en 18 TW. Además, todos los depósitos de energía fósil recon...

  17. Solar photovoltaic/thermal (hybrid) energy project

    Science.gov (United States)

    Sheldon, D. B.

    1981-09-01

    Development of photovoltaic/thermal (PV/T) collectors and residential heat pump systems is reported. Candidate collector and residential heat pump systems were evaluated using the TRNSYS computer program. It is found that combined heat pump and PV array is a promising method for achieving economical solar cooling. Where the cooling load is dominant, exclusively PV collectors rather than PV/T collectors are preferred. Where the heating load is dominant, the thermal component of PV/T collectors makes a significant contribution to heating a residence. PV/T collectors were developed whose combined efficiency approaches the efficiency of a double glazed, exclusively thermal collector. The design and operational problems of air source heat pumps are reviewed. Possible effects of compressor startup transients on PV power system operation are discussed.

  18. The calibration and initial results of the HeI D3 line flash spectrum obtained during the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    LI Hui; ZHOU TuanHui; LI JingWei; SHEN JinHua; JI HaiSheng; NI HouKun; ZHANG HaiYing; ZHANG YaNan; LIU HongRui; DENG YuanYong; WANG DongGuang; DU QiuSheng

    2009-01-01

    The flash spectra in the Hel D3 line were obtained during the 2008 total solar eclipse. This paper describes the instrument and the calibration of the obtained flash spectrum, and presents our initial results.The average integrated intensity is E_(ave)=8.13×10~(13)erg·cm~(-1)·s~(-1)·ster~(-1)ath=1100km,which confirms that the Hel D3 emission is negatively correlated with the solar activity. The surface brightness reaches a maximum of F_(ave)=8.25×10~5 erg·cm~(-2)·s~(-1)·ster(-1) at about h≈(1290±75) km and then decreases exponentially with height when h > 1800 km with an exponential index β= 1.63×10~(-8)cm~(-1).

  19. The calibration and initial results of the HeI D3 line flash spectrum obtained during the 2008 total solar eclipse

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The flash spectra in the HeI D3 line were obtained during the 2008 total solar eclipse. This paper describes the instrument and the calibration of the obtained flash spectrum, and presents our initial results. The average integrated intensity is Eave = 8.13×1013 erg·cm-1· s-1·ster-1 at h = 1100 km, which confirms that the HeI D3 emission is negatively correlated with the solar activity. The surface brightness reaches a maximum of F ave = 8.25×105 erg·cm-2·s-1·ster-1 at about h ≈ (1290 ± 75) km and then decreases exponentially with height when h >1800 km with an exponential index β = 1.63×10-8 cm-1.

  20. Organic / IV, III-V Semiconductor Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Pang-Leen Ong

    2010-03-01

    Full Text Available We present a review of the emerging class of hybrid solar cells based on organic-semiconductor (Group IV, III-V, nanocomposites, which states separately from dye synthesized, polymer-metal oxides and organic-inorganic (Group II-VI nanocomposite photovoltaics. The structure of such hybrid cell comprises of an organic active material (p-type deposited by coating, printing or spraying technique on the surface of bulk or nanostructured semiconductor (n-type forming a heterojunction between the two materials. Organic components include various photosensitive monomers (e.g., phtalocyanines or porphyrines, conjugated polymers, and carbon nanotubes. Mechanisms of the charge separation at the interface and their transport are discussed. Also, perspectives on the future development of such hybrid cells and comparative analysis with other classes of photovoltaics of third generation are presented.

  1. 日全食期间的杭州气象要素变化%Changes of Upper Air Meteorological Elements during Total Solar Eclipse

    Institute of Scientific and Technical Information of China (English)

    华行祥; 朱兰娟; 杨焕强

    2013-01-01

    2009年7月22日,杭州国家基准气候站进行日全食前、中、后三次的高空对比观测,探究日全食对高空气象要素的影响.观测结果表明,在20000余米高空的同一高度上,有无太阳辐射的温度差异在0.6~3.0℃之间,变化较明显,气压、湿度变化不明显,主要是受仪器误差和日变化影响;地面温度最大差值为2.3℃,变化较明显,气压、湿度变化不大,主要是仪器误差和日变化影响造成的.%On July 22,2009,Hangzhou National Reference Climatological Station carried out three upper air comparative observations before,during and after the total solar eclipse,and explored the effect of total solar eclipse on upper air meteorological elements.Observation results show that at the same height of about 20,000-meter upper air,temperature difference between the place with solar radiation and the place without solar radiation is 0.6-3.0℃,which is obvious; Changes of air pressure and humidity are unobvious,mainly affected by instrument errors and diurnal changes.Maximum difference of ground temperature is 2.3℃,which is obvious; Changes of air pressure and humidity are unobvious,mainly affected by instrument errors and diurnal changes.

  2. Efficient Organic/Inorganic Hybrid Solar Cell Integrating Polymer Nanowires and Inorganic Nanotetrapods

    National Research Council Canada - National Science Library

    Xu, Weizhe; Tan, Furui; Liu, Xiansheng; Zhang, Weifeng; Qu, Shengchun; Wang, Zhijie; Wang, Zhanguo

    2017-01-01

    ...% in the hybrid solar cell, up to 42% enhancement compared to the reference solar cell with traditional P3HT molecules as electron donor. Our work provides a promising hybrid structure for efficient organic/inorganic bulk-heterojunction solar cells.

  3. Laser Crystallization of Organic-Inorganic Hybrid Perovskite Solar Cells.

    Science.gov (United States)

    Jeon, Taewoo; Jin, Hyeong Min; Lee, Seung Hyun; Lee, Ju Min; Park, Hyung Il; Kim, Mi Kyung; Lee, Keon Jae; Shin, Byungha; Kim, Sang Ouk

    2016-08-23

    Organic-inorganic hybrid perovskites attract enormous research interest for next generation solar energy harvest. Synergistic crystalline structures comprising organic and inorganic components enable solution processing of perovskite films. A reliable crystallization method for perovskites, compatible with fast continuous process over large-area flexible substrates, is crucial for high performance solar cell production. Here, we present laser crystallization of hybrid perovskite solar cells using near-infrared (NIR) laser (λ = 1064 nm). Crystalline morphology of CH3NH3PbI3 (MAPbI3) perovskite films are widely controllable with laser irradiation condition while maintaining film uniformity. Photothermal heating effectively assisted by interfacial photoconversion layers is critical for phase transformation without beam damage of multilayered device structures. Notably, laser crystallization attains higher device performances than conventional thermal annealing. Fast laser crystallization with manufacture level scan rate (1 m min(-1)) demonstrates inverted-type perovskite solar cells with 11.3 and 8.0% efficiencies on typical glass and flexible polymer substrates, respectively, without rigorous device optimization.

  4. Analysis of a Hybrid Solar-Assisted Trigeneration System

    Directory of Open Access Journals (Sweden)

    Elisa Marrasso

    2016-09-01

    Full Text Available A hybrid solar-assisted trigeneration system is analyzed in this paper. The system is composed of a 20 m2 solar field of evacuated tube collectors, a natural gas fired micro combined heat and power system delivering 12.5 kW of thermal power, an absorption heat pump (AHP with a nominal cooling power of 17.6 kW, two storage tanks (hot and cold and an electric auxiliary heater (AH. The plant satisfies the energy demand of an office building located in Naples (Southern Italy. The electric energy of the cogenerator is used to meet the load and auxiliaries electric demand; the interactions with the grid are considered in cases of excess or over requests. This hybrid solution is interesting for buildings located in cities or historical centers with limited usable roof surface to install a conventional solar heating and cooling (SHC system able to achieve high solar fraction (SF. The results of dynamic simulation show that a tilt angle of 30° maximizes the SF of the system on annual basis achieving about 53.5%. The influence on the performance of proposed system of the hot water storage tank (HST characteristics (volume, insulation is also studied. It is highlighted that the SF improves when better insulated and bigger HSTs are considered. A maximum SF of about 58.2% is obtained with a 2000 L storage, whereas the lower thermal losses take place with a better insulated 1000 L tank.

  5. Hybrid inorganic-organic tandem solar cells for broad absorption of the solar spectrum

    NARCIS (Netherlands)

    Speirs, M. J.; Groeneveld, B. G. H. M.; Protesescu, L.; Piliego, Claudia; Kovalenko, M. V.; Loi, M. A.

    2014-01-01

    We report the first hybrid tandem solar cell with solution processable active layers using colloidal PbS quantum dots (QDs) as the front subcell in combination with a polymer-fullerene rear subcell. Al/WO3 is introduced as an interlayer, yielding an open circuit voltage (V-OC) equal to about 92% of

  6. Techno-economic assessment of a hybrid solar receiver and combustor

    Science.gov (United States)

    Lim, Jin Han; Nathan, Graham; Dally, Bassam; Chinnici, Alfonso

    2016-05-01

    A techno-economic analysis is performed to compare two different configurations of hybrid solar thermal systems with fossil fuel backup to provide continuous electricity output. The assessment compares a Hybrid Solar Receiver Combustor (HSRC), in which the functions of a solar cavity receiver and a combustor are integrated into a single device with a reference conventional solar thermal system using a regular solar cavity receiver with a backup boiler, termed the Solar Gas Hybrid (SGH). The benefits of the integration is assessed by varying the size of the storage capacity and heliostat field while maintaining the same overall thermal input to the power block.

  7. Sun-Earth Day:2008 Space Weather Around the World Total Solar Eclipse of 2008 August 1st in Siberia

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A very unique astronomical phenomenon will take place on the territory of Russia on the 1st August 2008.The total eclipse with a width of about 250 km will cross the Western Siberia from the north to the south,then will cross the Altai Mountains and will go further to the difficult to access regions of China and Mongolia.

  8. Hybrid thermoelectric solar collector design and analysis

    Science.gov (United States)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  9. Hybrid thermoelectric solar collector design and analysis

    Science.gov (United States)

    Roberts, A. S., Jr.; Shaheen, K. E.

    1982-01-01

    A flat-plate solar collector is conceived where energy cascades through thermoelectric power modules generating direct-current electricity. The intent of this work was to choose a collector configuration and to perform a steady-state thermal performance assessment. A set of energy balance equations were written and solved numerically for the purpose of optimizing collector thermal and electrical performance. The collector design involves finned columns of thermoelectric modules imbedded in the absorber plate (hot junction) over a parallel array of vertical tubes. The thermoelectric power output is limited by the small hot-junction/cold-junction temperature difference which can be maintained under steady-state conditions. The electric power per unit tube pass area is found to have a maximum as a function of a geometric parameter, while electric power is maximized with respect to an electric resistance ratio. Although the electric power efficiency is small, results indicate that there is sufficient electric power production to drive a coolant circulator, suggesting the potential for a stand-alone system.

  10. Get Ready for the Great American Eclipse!

    Science.gov (United States)

    Fulco, Charles

    2017-01-01

    This year marks 38 years since any part of the continental United States was darkened by the Moon's umbral shadow. During this "eclipse drought," no U.S. residents except those on Hawaii's Big Island in 1991 have had the opportunity to observe totality without traveling abroad. The 2017 Total Solar Eclipse (TSE2017, August 21, 2017) is…

  11. Meteorological effects of the solar eclipse of 20 March 2015: analysis of UK Met Office automatic weather station data and comparison with automatic weather station data from the Faroes and Iceland

    Science.gov (United States)

    Penman, John; Jónsson, Trausti; Bigg, Grant R.; Björnsson, Halldór; Sjúrðarson, Sølvi; Hansen, Mads A.; Cappelen, John; Bryant, Robert G.

    2016-01-01

    Here, we analyse high-frequency (1 min) surface air temperature, mean sea-level pressure (MSLP), wind speed and direction and cloud-cover data acquired during the solar eclipse of 20 March 2015 from 76 UK Met Office weather stations, and compare the results with those from 30 weather stations in the Faroe Islands and 148 stations in Iceland. There was a statistically significant mean UK temperature drop of 0.83±0.63°C, which occurred over 39 min on average, and the minimum temperature lagged the peak of the eclipse by about 10 min. For a subset of 14 (16) relatively clear (cloudy) stations, the mean temperature drop was 0.91±0.78 (0.31±0.40)°C but the mean temperature drops for relatively calm and windy stations were almost identical. Mean wind speed dropped significantly by 9% on average during the first half of the eclipse. There was no discernible effect of the eclipse on the wind-direction or MSLP time series, and therefore we can discount any localized eclipse cyclone effect over Britain during this event. Similar changes in air temperature and wind speed are observed for Iceland, where conditions were generally clearer, but here too there was no evidence of an eclipse cyclone; in the Faroes, there was a much more muted meteorological signature. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’. PMID:27550769

  12. A Profound AnalogyOn the Themes of Solar Eclipse by Yang Zhao%一个深刻的隐喻——杨昭小说《日蚀》的主题分析

    Institute of Scientific and Technical Information of China (English)

    唐光国

    2012-01-01

    小说《日蚀》叙写了民国后期的一场日食,讲述了一串发生在永康镇的令人啼笑皆非的故事,揭示了一个重大而深刻的主题。从科学遭受"日食"、真相遭受"日食"、伦理道德遭受"日食"三个方面的剖析,挖掘出小说的主题在于通过一场自然界的日食隐喻一场天昏地暗的"社会日食",从而再现那段黑暗的社会生活。%While depicting a solar eclipse happened in the late period of the Republic of China, the novel Solar Eclipse tells the reader a series of ironical stories staged in Yong Kang Town and reveals an important and profound theme. The author's criticism of the eclipse or the distortion and the spoilage of the science, the truth and the morality shows that the novel's theme is to compare the natural eclipse to a desperate social eclipse reproduce and reveal the dark social life.

  13. Eclipse of epsilon Aurigae

    Science.gov (United States)

    Templeton, Matthew R.

    2009-07-01

    The bright, long-period, eclipsing binary star epsilon Aurigae is predicted to begin its next eclipse late July or early August of 2009. Epsilon Aurigae is now past solar conjunction and has reappeared as a morning object. All observers -- both visual and instrumental -- are encouraged to contribute observations of the eclipse during the next two years, beginning immediately for morning observers. Observations are urgently requested right now because it is less likely to be observed in the morning, and the eclipse will begin within the next month. The AAVSO is participating in a global campaign to record this eclipse as part of the International Year of Astronomy 2009 celebrations, organized by the Citizen Sky project (http://www.citizensky.org). For experienced visual observers, please observe this star on a weekly basis, using charts available via VSP from the AAVSO website. For novice visual observers, we recommend participating in this observing program by following the Citizen Sky 10-Star tutorial program, which provides a simple training experience in variable star observing. Photoelectric observers belonging to the AAVSO PEP-V program may submit data as usual via the WebObs feature of the AAVSO website Blue&Gold section. Photoelectric observers may also contribute reduced observations in all filters (including infrared J- and H-bands) directly to the AAVSO via WebObs. Observers using wide-field CCD and DSLR systems are also encouraged to participate; avoid saturating the star. For those with narrower-field systems (D Jeffrey Hopkins are co-leading the precision photometry efforts.

  14. Evaluation of hybrid solar – biomass dryer with no load

    Directory of Open Access Journals (Sweden)

    Yassen Tadahmun Ahmed

    2014-07-01

    Full Text Available Experimental study was carried out to investigate the performance of designed and fabricated hybrid solar-biomass dryer without load. The solar side was a natural convection mixed mode, while the biomass side was a hot air produced from a burner/gas to gas heat exchanger. The experiments have been conducted to test the dryer temperature, inlet and outlet relative humidity, outlet velocity, and biomass feeding rate. In the solar mode the maximum dryer temperature was 63°C. Behaviours of the velocity in the dryer was found to follow solar radiation available to the dryer. The velocity was in the range of 0.6 – 1.35 m/s through the 0.0176 m2 area of the outlet when the solar radiation was in the range of 150 – 880 W/m2. Two feeding rates of wood were used to investigate the dryer performance through the night. The results showed that at feeding rate 278 g/hr, the drying air mean temperature was 62 ºC. This temperature was more suitable than the measured drying air temperature at feeding rate 490 g/hr. Also the 62 °C drying environment is more stable and feasible for drying almost all types of products.

  15. Field tests of a natural vacuum solar desalination system using hybrid solar collector

    Science.gov (United States)

    Setyawan, Eko Y.; Napitupulu, Richard A. M.; Siagian, Parulian; Ambarita, Himsar

    2017-09-01

    This study deals with field test of a natural vacuum solar desalination system using hybrid type solar collector. In order to perform the tests, a natural vacuum solar desalination has been designed and fabricated. The dimension of evaporator is 1000 mm ×1000 mm × 200 mm, while dimension of solar collector is 1000 mm ×1500 mm. The system is tested by exposing to solar radiation in Medan city of Indonesia for five days. The solar radiations during test are 8.79 MJ/m2, 10.14 MJ/m2, 6.88 MJ/m2, 11.05 MJ/m2, and 11.36 MJ/m2, respectively. The produced fresh waters are 160 ml, 180 ml, 118 ml, 206 ml, 220 ml, respectively. The conclusions are as follows. The produced fresh water is still very low due to the heat from the solar collector is not transferred perfectly to the evaporator. There produced fresh water is strongly affected by solar irradiation. It is recommended to minimize the heat loss from the evaporator and the transfer fluid.

  16. Obtaining Electron Temperatures and Flow Speeds from Thomson Scattered Coronal Emission Observed during the 29 March 2006 Total Solar Eclipse in Libya

    Science.gov (United States)

    Davila, Joseph M.; Geginald, Nelson L.; Gashut, Hadi; Guhathakurta, Madhulika; Hassler, Donald M.

    2008-01-01

    An experiment to measure the electron temperature and flow speed in the solar corona by observing the visible K-coronal spectrum was conducted during the total solar eclipse on 29 March 2006 in Libya. New corona1 models accounting for the effect of electron temperature and flow on the resulting K-corona spectrum were used to interpret the observations. Results show electron temperatures of 1.10 +/- 0.05, 0.98 +/- 0.12, and 0.70 +/- 0.08 MK, at l.l{\\it R)$-{\\odot)$ in the solar north, east and west, respectively, and 0.93 +/- 0.12 MK, at 1.2 R(sub sun) in the solar east. The corresponding outflow speeds obtained from the spectral fit are 103 +/- 92, 0 + 10, 0 + 10, and 0 + 10 km/s. Since the observations are taken only at 1.1 and 1.2 R(sub sun) these velocities , consistent with zero outflow, are in agreement with expectations and provide additional confirmation that the spectral fitting method is working.

  17. Obtaining Electron Temperatures and Flow Speeds from Thomson Scattered Coronal Emission Observed during the 29 March 2006 Total Solar Eclipse in Libya

    Science.gov (United States)

    Davila, Joseph M.; Geginald, Nelson L.; Gashut, Hadi; Guhathakurta, Madhulika; Hassler, Donald M.

    2008-01-01

    An experiment to measure the electron temperature and flow speed in the solar corona by observing the visible K-coronal spectrum was conducted during the total solar eclipse on 29 March 2006 in Libya. New corona1 models accounting for the effect of electron temperature and flow on the resulting K-corona spectrum were used to interpret the observations. Results show electron temperatures of 1.10 +/- 0.05, 0.98 +/- 0.12, and 0.70 +/- 0.08 MK, at l.l{\\it R)$-{\\odot)$ in the solar north, east and west, respectively, and 0.93 +/- 0.12 MK, at 1.2 R(sub sun) in the solar east. The corresponding outflow speeds obtained from the spectral fit are 103 +/- 92, 0 + 10, 0 + 10, and 0 + 10 km/s. Since the observations are taken only at 1.1 and 1.2 R(sub sun) these velocities , consistent with zero outflow, are in agreement with expectations and provide additional confirmation that the spectral fitting method is working.

  18. Eclipse 2017: Through the eyes of NASA

    Science.gov (United States)

    Mayo, Louis; NASA/GSFC Heliophysics Education Consortium

    2016-10-01

    The August 21, 2017 eclipse will be the first time a total solar eclipse has traversed the Continental US since June 8th, 1918. Anticipation y for energy for this eclipse is off the charts. Over 500 million in North America alone will catch the eclipse in either partial or total phase. Parts of South America, Africa, and Europe will see a partial eclipse as well. NASA is planning to take full advantage of this unique celestial event as an education and public engagement opportunity by leveraging its extensive networks of partners, numerous social media platforms, broadcast media, and its significant unique space assets and people to bring the eclipse to America and the world as only NASA can. This talk will outline NASA's education plans in some detail replicating our many Big Events successes including the 2012 Transit of Venus and the MSL/Curiosity landing and show how scientists and the public can get involved.

  19. Daytime E-Region Irregularities During the 22 July 2009 Solar Eclipse over Chung-Li (24.9°N, 121.2°E, a Moderate Mid-Latitude Station

    Directory of Open Access Journals (Sweden)

    Potula Sree Brahmanandam

    2013-01-01

    Full Text Available The 22 July 2009 solar eclipse with an obscuration of > 83% at Chung-Li (24.9¢XN, 121.2¢XE, Dip 35¢XN in Taiwan during noon hours has provided a unique opportunity for us to examine its impact on E-region irregularities which were observed simultaneously by the 52 MHz coherent radar and a co-located ionosonde. Significant observations revealed that the daytime E-region strong backscatter echoes at multiple heights and a sudden intensification of the weak sporadic E-layer during the 22 July 2009 solar eclipse. These results follow the research findings of Patra et al. (2009. As the incident solar radiation suddenly blocked by intruding Moon during solar eclipse events that would generally create night-like ionospheric conditions, it is surmised that the E-region irregularities were indeed induced by the eclipse associated effects. The induced effects resulted in faster recombination of molecular ions, generation of gravity waves and electric fields that could have created a conducive environment to excite plasma irregularities through a gradient-drift instability mechanism. The vertical shears of radar Doppler velocity and the peak radar backscatter at the node of Doppler velocity shear, as resolved by the coherent scatter radar with interferometer technique, were possibly due to the upward propagating gravity waves and wave-induced polarization electric fields. The present observational results should not only be highly useful to ascertain plausible mechanisms responsible for nighttime E-region irregularities, but also provided evidence that a solar eclipse could generate E-region plasma irregularities over temperate mid-latitudes for the first time.

  20. Precise mass and radius measurements for the components of the bright solar-type eclipsing binary star V1094 Tau

    CERN Document Server

    Maxted, P F L; Torres, G; Lacy, C H S; Southworth, J; Smalley, B; Pavlovski, K; Marschall, L A; Clausen, J V

    2015-01-01

    V1094 Tau is bright eclipsing binary star with an orbital period close to 9 days containing two stars similar to the Sun. Our aim is to test models of Sun-like stars using precise and accurate mass and radius measurements for both stars in V1094 Tau. We present new spectroscopy of V1094 Tau which we use to estimate the effective temperatures of both stars and to refine their spectroscopic orbits. We also present new, high-quality photometry covering both eclipses of V1094 Tau in the Stroemgren uvby system and in the Johnson V-band. The masses, radii and effective temperatures of the stars in V1094 Tau are found to be M$_A$ = 1.0964 $\\pm$ 0.0040 M$_{\\odot}$, R$_A$ = 1.4129 $\\pm$ 0.0058 R$_{\\odot}$, T$_{\\rm eff,A}$ = 5850 $\\pm$ 100 K, and M$_B$ = 1.0120 $\\pm$ 0.0028 M$_{\\odot}$, R$_B$ = 1.0913 $\\pm$ 0.0066 R$_{\\odot}$, T$_{\\rm eff,B}$ = 5700 $\\pm$ 100 K. An analysis of the times of mid-eclipse and the radial velocity data reveals apsidal motion with a period of 14500 $\\pm$ 3700 years. The observed masses, radii...

  1. Electromagnetic lower hybrid instability in the solar wind

    Energy Technology Data Exchange (ETDEWEB)

    Lakhina, G.S.

    1985-04-01

    A fully electromagnetic lower hybrid instability which is driven by a resonant halo electron component is studied analytically. It is shown that the growth rate of the instability peaks at a certain value of the wave-number and that an increase in the ratio of electron pressure to magnetic field pressure reduces the growth rate. At 0.3 AU the typical growth time for the instability is found to be of the order of 25 ms or less, whereas the most unstable wavelengths associated with the instability fall typically in a range of 27 to 90 km. Relevance of electromagnetic lower hybrid instability to the obliquely propagating whistler, characterized by large values of refractive indices, detected behind interplanetary shocks in the solar wind and to the generation mechanism of correlated whistler and electron-plasma oscillation bursts detected on ISEE-3 are discussed. 17 references.

  2. Recent progress in efficient hybrid lead halide perovskite solar cells

    Science.gov (United States)

    Cui, Jin; Yuan, Huailiang; Li, Junpeng; Xu, Xiaobao; Shen, Yan; Lin, Hong; Wang, Mingkui

    2015-01-01

    The efficiency of perovskite solar cells (PSCs) has been improved from 9.7 to 19.3%, with the highest value of 20.1% achieved in 2014. Such a high photovoltaic performance can be attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths of the hybrid lead halide perovskite materials. In this review, some fundamental details of hybrid lead iodide perovskite materials, various fabrication techniques and device structures are described, aiming for a better understanding of these materials and thus highly efficient PSC devices. In addition, some advantages and open issues are discussed here to outline the prospects and challenges of using perovskites in commercial photovoltaic devices. PMID:27877815

  3. Recent progress in efficient hybrid lead halide perovskite solar cells.

    Science.gov (United States)

    Cui, Jin; Yuan, Huailiang; Li, Junpeng; Xu, Xiaobao; Shen, Yan; Lin, Hong; Wang, Mingkui

    2015-06-01

    The efficiency of perovskite solar cells (PSCs) has been improved from 9.7 to 19.3%, with the highest value of 20.1% achieved in 2014. Such a high photovoltaic performance can be attributed to optically high absorption characteristics and balanced charge transport properties with long diffusion lengths of the hybrid lead halide perovskite materials. In this review, some fundamental details of hybrid lead iodide perovskite materials, various fabrication techniques and device structures are described, aiming for a better understanding of these materials and thus highly efficient PSC devices. In addition, some advantages and open issues are discussed here to outline the prospects and challenges of using perovskites in commercial photovoltaic devices.

  4. Study on the Ionospheric TEC Variations During the Total Solar Eclipse of July 22,2009%2009年7月22日日全食期间电离层总电子含量变化研究

    Institute of Scientific and Technical Information of China (English)

    莫晓华; 张东和; 覃健生; 叶锦凤; 萧佐

    2012-01-01

    Variations of the ionospheric Total Electron Content(TEC) during the total solar eclipse of July 22,2009 was investigated using GPS observed data obtained at five GPS stations(one is in total solar eclipse region,the others are in partial solar eclipse region) in China region.Results indicate that during the total solar eclipse,TEC experiences a decline and recovery process;the delay of a minimum level of TEC with respect to the maximum phase of the eclipse is about 1~10min;the Ionosphere Pierce Point(IPP) of minimum TEC is closer to total solar eclipse region,the decrease of TEC is larger,and during the total solar eclipse,the mean decay TEC compared to the TEC on reference date above WUHN station(114.35°E,30.53°N) is the maximum,reaching 4.58 TECU.%利用中国区域内五个GPS台站(一个台站处于日全食区域、四个台站处于日偏食区域)观测数据,研究2009年7月22日日全食期间电离层总电子含量(TEC)的变化,结果表明,日全食期间,电离层TEC值经历了下降和恢复的过程,最小TEC相对于最大食偏的时间延迟约为1~10 min;台站测得最小TEC的星下点(IPP)越靠近日全食带TEC下降量越大,在日食期间武汉站(114.35°E,30.53°N)TEC相对于各参考日期的TEC,其平均下降量最大,达到4.58TECU.

  5. Three Sides Billboard Wind-Solar Hybrid System Design

    Directory of Open Access Journals (Sweden)

    Bai Xuefeng

    2015-01-01

    Full Text Available With the high development of world economy, the demand of energy is increasing all the time, As energy shortage and environment problem are increasing outstanding, Renewable energy has been attracting more and more attention. A kind of three sides billboard supply by wind-Solar hybrid system has been designed in this paper, the overall structure of the system, components, working principle and control strategy has been analyzed from the system perspective. The software and hardware of the system are debugged together and the result is acquired. System function is better and has achieved the expected results.

  6. Organic-inorganic hybrid solar cells via electropolymerization

    Science.gov (United States)

    Feng, Wenchun

    Integrating polymers with inorganic nanostructures is difficult due to wetting and surface energy considerations. We developed an electropolymerization method to grow conformal polymers on high aspect ratio nanostructures. Our method is shown to improve the polymer filling rate inside the nanostructures and can be used in the development of efficient hybrid solar cells. As an example, we have studied the hybrid system of electropolymerized polythiophene (e-PT) on a variety of conductive (Au and ITO) and semiconductive substrates (Si, Ge, ZnO). In particular, e-PT/ZnO hybrid structure can be further developed into organic photovoltaics (OPV). Although unsubstituted PT is not the ideal polymer material for high efficiency solar cells, it is an excellent choice for studying basic bonding and morphology in hybrid structures. We find that e-PT is covalently bound to the polar ZnO planar substrate via a Zn-S bond, adopting an upright geometry. By contrast, no strong covalent bonding was observed between e-PT and ZnO nanorods that consist of non-polar ZnO surfaces predominantly. Energy level alignment at interfaces is critical for fundamental understanding and optimization of OPV as band offsets of the donor and acceptor materials largely determine the open circuit voltage (Voc) of the device. Using ultraviolet photoemission spectroscopy (UPS) and inverse photoemission spectroscopy (IPS), we examined the correlation between energy alignment and photovoltaic properties of a model hybrid solar cell structure incorporating undoped electrodeposited polythiophene (e-PT) films on ZnO planar substrates. The electrolyte anion (BF4-, PF6 -, ClO4- or CF3SO3 -) used in the electrodeposition solution was found to exert a strong influence on the neutral e-PT film morphology and adhesion, the band alignment at the interface, and ultimately the photovoltaic behavior. The interfacial dipole lowers polythiophene energy levels, increasing the theoretical and actual Voc in polythiophene

  7. Experimental estimation of effective recombination coefficients in the D-region ionosphere at high latitudes during solar eclipses by the method of partial reflections

    Directory of Open Access Journals (Sweden)

    Chernyakov S. M.

    2017-03-01

    Full Text Available The photochemical theory of processes in the lower ionosphere is very complicated and up to now it is not completely developed. Therefore introduction of the effective coefficients determining the total speed of several important reactions has been widely adopted when modeling the D-region of the ionosphere. Experimental opportunities for obtaining effective recombination coefficients are rather limited. One of the methods to estimate effective recombination coefficients uses the phenomenon of a solar eclipse. The basis of this method is the idea of Appleton about similarity of the behavior of the linear inductive circuit and variations of the electron concentration in the ionosphere on a fixed height in the absence of the transport processes, the change in the rate of formation of electrons in time and the disappearance of free electrons due to recombination. By analogy with the time constant of the electric circuit Appleton called the reaction of the ionosphere on the process of ionization in the ionosphere as "sluggishness" with a characteristic time constant τ, which is also called the "relaxation time" or "time constant of the ionosphere". During 11 August 1999, 1 August 2008, 11 June 2011, 20 March 2015 solar eclipses at the partial reflection facility of the observatory "Tumanny" (69.0N, 35.7E observations of the amplitudes of reflections of ordinary and extraordinary waves have been carried out. Using the obtained data the two-dimensional (time, height distribution of the electron density ne at altitudes of the D-region ionosphere has been calculated. This has made it possible to obtain the behavior of the electron concentration in time at selected altitudes (temporal profiles of electron density at selected altitudes. Using the obtained experimental profiles, the effective recombination coefficients on the heights of the D-region ionosphere have been evaluated. Transport processes of plasma (for example, propagation of acoustic

  8. Design, Construction and Effectiveness Analysis of Hybrid Automatic Solar Tracking System for Amorphous and Crystalline Solar Cells

    OpenAIRE

    Bhupendra Gupta

    2013-01-01

    - This paper concerns the design and construction of a Hybrid solar tracking system. The constructed device was implemented by integrating it with Amorphous & Crystalline Solar Panel, three dimensional freedom mechanism and microcontroller. The amount of power available from a photovoltaic panel is determined by three parameters, the type of solar tracker, materials of solar panel and the intensity of the sunlight. The objective of this paper is to present analysis on the use of two differ...

  9. Photometric analysis of the corona during the 20 March 2015 total solar eclipse: density structures, hydrostatic temperatures and magnetic field inference

    CERN Document Server

    Bazin, C; Wittich, R; Koutchmy, S; Mouette, J; Nitschelm, C

    2015-01-01

    We present some new accurate CCD photometry analysis of the white light solar corona at the time of the last 20 March 2015 total eclipse (airborne observations on a Falcon 7X and at ground-based Svalbard). We measured coronal brightness profiles taken along radial directions from 1.001 to 3 solar radii in the northern, southern and equatorial regions, after removing the F corona and the sky background. These studies allow to evaluate the density gradients, structures and temperature heterogeneity, by considering the Thomson scattering in white light of the K corona and also emissions of the EUV Fe XII 193A (1 to 2 MK) and Fe XI 171/174 (lower temperature) simultaneously observed by SDO/AIA and SWAP Proba2 space missions. Some dispersion between the regions is noticed. The limitation of the hydrostatic equilibrium assumption in the solar atmosphere is discussed as well as the contribution of the magnetic field pressure gradients as illustrated by a comparison with the model stationary magnetic corona from Pred...

  10. Combustion system for hybrid solar fossil fuel receiver

    Science.gov (United States)

    Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

    2004-05-25

    A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber. A heat-exchanger is operatively associated and in thermal contact with the combustion chamber. The heat-exchanger provides heat for the hybrid solar receiver.

  11. Organic Inorganic Hybrid Solar Cell Efficiency Improvement By Employing Au Nanocluster

    Science.gov (United States)

    2015-06-14

    Specialists Conference Conference Date: June 14, 2015 Organic - Inorganic Hybrid Solar Cell Efficiency Improvement by Employing Au Nanocluster Manisha...tunable conductivity, organic polymer, heterojunction, nanocluster I. INTRODUCTION Recently, organic / inorganic hybrid heterojunction solar cells have...conventional Si p−n junction. These heterojunction devices are intended to exploit the advantageous properties of both organic and inorganic materials

  12. A Hybrid Tandem Solar Cell Combining a Dye-Sensitized and a Polymer Solar Cell.

    Science.gov (United States)

    Shao, Zhipeng; Chen, Shuanghong; Zhang, Xuhui; Zhu, Liangzheng; Ye, Jiajiu; Dai, Songyuan

    2016-06-01

    A hybrid tandem solar cell was assambled by connecting a dye sensitized solar cell and a polymer solar cell in series. A N719 sensitized TiO2 was used as photocathode in dye-sensitized subcell, and a MEH-PPV/PCBM composite was used as active layer in the polymer subcell. The polymer subcell fabricated on the counter electrode of the dye sensitized solar cell. A solution processed TiO(x) layer was used as electron collection layer of the polymer sub cell and the charge recombination layer. The effects of the TiO(x) interlayer and the spectral overlap between the two sub cells have been studied and optimized. The results shows that a proper thickness of the TiO(x) layer is needed for tandem solar cells. Thick TiO(x) will enhance the series resistance, but too thin TiO(x), layer will damage the hole blocking effect and its hydrophilic. The resulting optimized tandem solar cells exhibited a power conversion efficiency of 1.28% with a V(oc) of 0.95 V under simulated 100 mW cm(-2) AM 1.5 illumination.

  13. Si/PEDOT:PSS core/shell nanowire arrays for efficient hybrid solar cells.

    Science.gov (United States)

    Lu, Wenhui; Wang, Chengwei; Yue, Wei; Chen, Liwei

    2011-09-01

    A solution filling and drying method has been demonstrated to fabricate Si/PEDOT:PSS core/shell nanowire arrays for hybrid solar cells. The hybrid core/shell nanowire arrays show excellent broadband anti-reflection, and resulting hybrid solar cells absorb about 88% of AM 1.5G photons in the 300-1100 nm range. The power conversion efficiency (PCE) of the hybrid solar cell reaches 6.35%, and is primarily limited by direct and indirect interfacial recombination of charge carriers.

  14. Improved performance of silicon nanowire/cadmium telluride quantum dots/organic hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Zhaoyun [National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu Province (China); Xu, Ling, E-mail: xuling@nju.edu.cn [National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China); Zhang, Renqi; Xue, Zhaoguo; Wang, Hongyu; Xu, Jun; Yu, Yao; Su, Weining; Ma, Zhongyuan; Chen, Kunji [National Laboratory of Solid State Microstructures and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093 (China)

    2015-04-15

    Highlights: • We introduce an intermediate cadmium telluride quantum dots (CdTe QDs) layer between the organic with silicon nanowires of hybrid solar cells as a down-shifting layer. • The hybrid solar cell got the maximum short circuit current density of 33.5 mA/cm{sup 2}, getting an increase of 15.1% comparing to solar cell without CdTe QDs. • The PCE of the hybrid solar cells with CdTe QDs layer increases 28.8%. - Abstract: We fabricated silicon nanowire/cadmium telluride quantum dots (CdTe QDs)/organic hybrid solar cells and investigated their structure and electrical properties. Transmission electron microscope revealed that CdTe QDs were uniformly distributed on the surface of the silicon nanowires, which made PEDOT:PSS easily filled the space between SiNWs. The current density–voltage (J–V) characteristics of hybrid solar cells were investigated both in dark and under illumination. The result shows that the performance of the hybrid solar cells with CdTe QDs layer has an obvious improvement. The optimal short-circuit current density (J{sub sc}) of solar cells with CdTe QDs layer can reach 33.5 mA/cm{sup 2}. Compared with the solar cells without CdTe QDs, J{sub sc} has an increase of 15.1%. Power conversion efficiency of solar cells also increases by 28.8%. The enhanced performance of the hybrid solar cells with CdTe QDs layers are ascribed to down-shifting effect of CdTe QDs and the modification of the silicon nanowires surface with CdTe QDs. The result of our experiments suggests that hybrid solar cells with CdTe QDs modified are promising candidates for solar cell application.

  15. Is an eclipse described in the Odyssey?

    Science.gov (United States)

    Baikouzis, Constantino; Magnasco, Marcelo O

    2008-07-01

    Plutarch and Heraclitus believed a certain passage in the 20th book of the Odyssey ("Theoclymenus's prophecy") to be a poetic description of a total solar eclipse. In the late 1920s, Schoch and Neugebauer computed that the solar eclipse of 16 April 1178 B.C.E. was total over the Ionian Islands and was the only suitable eclipse in more than a century to agree with classical estimates of the decade-earlier sack of Troy around 1192-1184 B.C.E. However, much skepticism remains about whether the verses refer to this, or any, eclipse. To contribute to the issue independently of the disputed eclipse reference, we analyze other astronomical references in the Epic, without assuming the existence of an eclipse, and search for dates matching the astronomical phenomena we believe they describe. We use three overt astronomical references in the epic: to Boötes and the Pleiades, Venus, and the New Moon; we supplement them with a conjectural identification of Hermes's trip to Ogygia as relating to the motion of planet Mercury. Performing an exhaustive search of all possible dates in the span 1250-1115 B.C., we looked to match these phenomena in the order and manner that the text describes. In that period, a single date closely matches our references: 16 April 1178 B.C.E. We speculate that these references, plus the disputed eclipse reference, may refer to that specific eclipse.

  16. Ionic transport in hybrid lead iodide perovskite solar cells

    Science.gov (United States)

    Eames, Christopher; Frost, Jarvist M.; Barnes, Piers R. F.; O'Regan, Brian C.; Walsh, Aron; Islam, M. Saiful

    2015-01-01

    Solar cells based on organic–inorganic halide perovskites have recently shown rapidly rising power conversion efficiencies, but exhibit unusual behaviour such as current–voltage hysteresis and a low-frequency giant dielectric response. Ionic transport has been suggested to be an important factor contributing to these effects; however, the chemical origin of this transport and the mobile species are unclear. Here, the activation energies for ionic migration in methylammonium lead iodide (CH3NH3PbI3) are derived from first principles, and are compared with kinetic data extracted from the current–voltage response of a perovskite-based solar cell. We identify the microscopic transport mechanisms, and find facile vacancy-assisted migration of iodide ions with an activation energy of 0.6 eV, in good agreement with the kinetic measurements. The results of this combined computational and experimental study suggest that hybrid halide perovskites are mixed ionic–electronic conductors, a finding that has major implications for solar cell device architectures. PMID:26105623

  17. Design, Construction and Effectiveness Analysis of Hybrid Automatic Solar Tracking System for Amorphous and Crystalline Solar Cells

    Directory of Open Access Journals (Sweden)

    Bhupendra Gupta

    2013-10-01

    Full Text Available - This paper concerns the design and construction of a Hybrid solar tracking system. The constructed device was implemented by integrating it with Amorphous & Crystalline Solar Panel, three dimensional freedom mechanism and microcontroller. The amount of power available from a photovoltaic panel is determined by three parameters, the type of solar tracker, materials of solar panel and the intensity of the sunlight. The objective of this paper is to present analysis on the use of two different material of Solar panel like Amorphous & Crystalline in a Solar tracking system at Stationary, Single Axis, Dual Axis & Hybrid Axis solar tracker to have better performance with minimum losses to the surroundings, as this device ensures maximum intensity of sun rays hitting the surface of the panel from sunrise to sunset

  18. TNB Experience in Developing Solar Hybrid Station at RPS Kemar, Gerik, Perak Darul Ridzuan

    Science.gov (United States)

    Aziz, K. A.; Shamsudin, K. N.

    2013-06-01

    This paper will discuss on TNB experience in developing Solar Hybrid Station at RPS Kemar, Gerik, Perak. TNB has been approached by KKLW to submit proposal to provide electricity in the rural area namely RPS Kemar. Looking at area and source available, Solar Hybrid System was the best method in order to provide electricity at this area. This area is far from national grid sources. Solar Hybrid System is the best method to produce electrical power using the renewable energy from Solar PV, Battery and Diesel Generator Set. Nowadays, price of petroleum is slightly high due to higher demand from industry. Solar energy is good alternative in this country to practice in order to reduce cost for produce of electrical energy. Generally, Solar will produce energy during daytime and when become cloudy and dark, automatically battery and diesel generator set will recover the system through the hybrid controller system.

  19. Fluxon Global Predictions for the 2017 Eclipse

    Science.gov (United States)

    DeForest, Craig; Lamb, Derek

    2017-08-01

    We present predicted coronal morphologies for the 2017 total solar eclipse, produced using quasi-stationary MHD simulation on a semi-Lagrangian grid with the FLUX code. FLUX uses the "fluxon" approach to ideal MHD: the magnetic field is modeled as a finite-element skeleton of field lines, which experience the familiar magnetic energy density ("pressure") and curvature ("tension") forces. Ongoing and recent work with FLUX enables simulation of solar wind flow and coronal density in the low-beta regime, and permits global 3-D solutions without the use of a supercomputer.Using magnetograms acquired up to one solar rotation before the eclipse, we expect to publish fluxon-derived models 2-3 weeks before the eclipse, and will present those models side-by-side with actual eclipse images to compare the model and actual coronae.

  20. Five Millennium Catalog of Lunar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE)

    Science.gov (United States)

    Espenak, Fred; Meeus, Jean

    2009-01-01

    This catalog is a supplement to the "FiveMillenniumCanonofLunarEclipses." It includes additional information for each eclipse that could not be included in the original publication because of size limits. The data tabulated for each eclipse include the catalog number, canon plate number, calendar date, Terrestrial Dynamical Time of greatest eclipse, (Delta)T, lunation number, Saros number, eclipse type, Quincena Solar Eclipse parameter, gamma, penumbral and umbral eclipse magnitudes, durations of penumbral, partial and total eclipse phases, and geographic coordinates of greatest eclipse (latitude and longitude). The Canon and the Catalog both use the same solar and lunar ephemerides as well as the same values of (Delta)T. This 1-to-1 correspondence between them will enhance the value of each. The researcher may now search, evaluate, and compare eclipses graphically (Canon) or textually (Catalog).