Topic
Solar eclipse
About: Solar eclipse is a research topic. Over the lifetime, 2737 publications have been published within this topic receiving 22625 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, the use of measurements combined with detailed stratospheric modeling of time dependent events, to confirm chemical mechanisms and their laboratory rate constants, is examined, and proposed measurements of the time dependent behavior of NO and NO2 to be made by U2 aircraft at 20-km altitude are also discussed.
Abstract: The use of measurements combined with detailed stratospheric modeling of time dependent events, to confirm chemical mechanisms and their laboratory rate constants, is examined. Careful simultaneous solutions of these equations have shown a significant daytime variation of ozone down to altitudes of about 30 km that can affect the interpretation of spectral absorption type experiments. The calculated sunset variations of NO and HO show a log linear concentration decay for limited time periods that can be readily converted into atmospheric temperatures by using known reaction rates up to about 70-km altitude. Proposed measurements of the time dependent behavior of NO and NO2 to be made by U2 aircraft at 20-km altitude are also discussed.
65 citations
TL;DR: In this paper, the authors compare the time fluctuations at various distances from totality on the eclipse and adjacent days, inside a 5° West to 5° East longitude area, and show the expected longitude transit of eclipse perturbation.
64 citations
TL;DR: In this article, the times required for the torsion pendulum to rotate through a given fixed part of its path, involving both clockwise and counterclockwise motions, on its first swing from rest were observed during the course of the eclipse as well as in the hours just preceding and just following the eclipse itself.
Abstract: During the solar eclipse of 7 March 1970, readings were taken and recorded electronically of the times required for the torsion pendulum to rotate through a given fixed part of its path, involving both clockwise and counterclockwise motions, on its first swing from rest. Significant variations in these times were observed during the course of the eclipse as well as in the hours just preceding and just following the eclipse itself. Between the onset of the eclipse and its midpoint there is a steady increase in the observed times. After the midpoint the times decrease suddenly and level off promptly to values considerably greater than those observed before the eclipse. Furthermore, before the eclipse there is a periodic variation in these times. This strange periodicity was essentially repeated two weeks later at the same hours, though the actual values were somewhat greater than the earlier ones. These increases in actual values exceed by a factor of ${10}^{5}$ those that can be explained by the attraction of the moon due to its change in position relative to the sun and earth. All this leads to the conclusion that classical gravitational theory needs to be modified to interpret these experimental facts.
63 citations
TL;DR: In this article, a wavelet analysis was used to identify twenty 4x4 arcsec2 areas showing intensity oscillations in the corona during the 1999 total solar eclipse. All detections lie in the frequency Hz (5-3 s), last for at least 3 periods at a confidence level of more than 99% and arise just outside known coronal loops, leading them to suggest that they occur in low emission-measure or different temperature loops associated with the active region.
Abstract: One of the mechanisms proposed for heating the corona above solar active regions is the damping of magnetohydrodynamic (MHD) waves. Continuing on previous work, we provide observational evidence for the existence of high-frequency MHD waves in coronal loops observed during the August 1999 total solar eclipse. A wavelet analysis is used to identify twenty 4x4 arcsec2 areas showing intensity oscillations. All detections lie in the frequency Hz (5-3 s), last for at least 3 periods at a confidence level of more than 99% and arise just outside known coronal loops. This leads us to suggest that they occur in low emission-measure or different temperature loops associated with the active region.
63 citations
TL;DR: The low-latitude ionospheric tomography network (LITN) consists of a chain of six Naval Navigation Satellite System (NNSS) receiving stations established along 121°E longitude from a geographic latitude of 14.6°N to 31°N as mentioned in this paper.
Abstract: The low-latitude ionospheric tomography network (LITN) consists of a chain of six Naval Navigation Satellite System (NNSS) receiving stations established along 121°E longitude from a geographic latitude of 14.6°N to 31°N. It is specifically designed to observe large-scale ionospheric variations over the equatorial anomaly region by using tomographic imaging techniques. Recently, the network LITN was applied to observations of the October 24, 1995, solar eclipse. Two-dimensional images of ionospheric electron density during the eclipse period were reconstructed. These images and the corresponding results from a nearby ionosonde were compared with those for a reference day. It is shown that during the eclipse day the ionosphere experienced some large-scale changes. In particular, four episodes of electron density enhancement or depression have been identified. (1) The maximum enhancement occurred before the maximum phase of the solar eclipse at approximately 7°–10°N geomagnetic latitude at the 275–300 km ionospheric height. (2) The second enhancement appeared roughly 3 1/2 hours after the maximum obscuration at 15°–22°N geomagnetic latitude and 300–325 km ionospheric height. (3) The largest electron density depression occurred roughly 2 hours after the maximum obscuration at approximately 9°–15°N geomagnetic latitude and on both the bottom and topside ionosphere. (4) The second depression occurred about 4 hours after the maximum obscuration at approximately 5.5°N geomagnetic latitude and mainly on the topside ionosphere. More detailed study suggests that the two enhancements have their origins in the ionospheric day-to-day variations, the first depression is related to the combined photochemical and the equatorial fountain effects, and the second depression may have its origin in geomagnetic coupling between conjugate ionospheres. These observations are interpreted within the framework of ionospheric dynamics in the equatorial anomaly region.
62 citations