Solar eclipse

About: Solar eclipse is a research topic. Over the lifetime, 2737 publications have been published within this topic receiving 22625 citations.

Dynamic processes in the near-ground atmosphere during the solar eclipse of August 1, 2008

Abstract: The optical observations and dynamics analysis of the effects in the near-ground atmosphere accompanying a partial (about 0.42 magnitude) solar eclipse (SE) near Kharkov, Ukraine, on August 1, 2008, are described in comparison with the effects of the partial eclipses on August 11, 1999, and October 3, 2005. All three SEs occurred around midday. The SE of August 1 was accompanied by a 2.0° decrease in the near-ground atmospheric temperature. It is found that, when the obscuration function was maximum (0.31), the standard deviation in the solar-limb displacement decreased by 0.30″. The measured fluctuations of the jitter level of the solar limb edge were used to estimate the parameters of the near-ground atmosphere and turbulence.

King Rama V and British Observations of the 6 April 1875 Total Solar Eclipse from the Chao Lai Peninsula, Siam

Abstract: In 1875 Sir Arthur Schuster of the University of Manchester led a Royal Society expedition to Siam (now Thailand) to observe a total solar eclipse. The expedition followed an invitation issued by the King of Siam, King Chulalongkorn (also known as King Rama V). Together with members of the Royal family, the British scientists undertook a number of experiments. Their success was later described by Schuster when he recalled that the importance of calcium in the chromosphere and prominences was first proven in the Siamese eclipse of 1875.

Radio observation of the solar eclipse of may 20, 1966.

Abstract: The eclipse of May 20, 1966 was observed at the wavelengths of 3.2 and 9.1 cm by three Arcetri expeditions. The curves obtained by deriving the occultation curves have been filtered by digital techniques to cut off high frequency noise; by them, many characteristics of three sources of the S-component present on the disk have been studied: temperature, dimensions, emitted flux and brightness distribution. Isophotes of the latter are compared with isophotes of the corresponding Hα plages for two sources: a close similarity results for one of them. Moreover it is shown that: (a) the height above the photosphere of the sources at λ = 9.1 cm is greater than that of the sources at λ = 3.2 cm; (b) the maximum of the radio emission is not always placed exactly above a sunspot or above the sunspot group barycentre. Fitting the observed brightness temperatures, as frequency functions, by a power law and using a temperature model of an active region, the electron density distribution can be deduced. The obtained electron density distributions are compared with various models of active regions.

Ionospheric Density Irregularities, Turbulence, and Wave Disturbances During the Total Solar Eclipse Over North America on 21 August 2017

Abstract: Data from ionosonde and GPS total electron content (TEC) observations reveal a number of ionospheric phenomena that occurred in response to the total solar eclipse on 21 August 2017 over North America. The eclipse started over the US west coast at ∼16:00 UTC (08:00 LT) and ended over the US east coast at ∼20:00 UTC (15:00 LT). We identify the growth of plasma density irregularities and turbulence on the bottomside ionosphere during the eclipse totality (at ∼10:34 LT over the Idaho station), signified by the distinct appearance of spread-F echoes in the ionosonde data. These spread-F echoes appeared in both O-mode and X-mode traces, and they lasted for approximately 10 minutes. Preceding the appearance of the spread echoes, an uplift of the ionospheric F-layer and steepening of the bottomside ionospheric density gradient were seen in the ionosonde data. In addition, data from the ionosonde observations also show some characteristic signatures of traveling ionospheric disturbances (TIDs) at ∼300 km altitude during the eclipse. The TIDs in the ionosonde observations were observed roughly 30 minutes after the time of maximum eclipse, and they have a wave periodicity of approximately 10 minutes. In other words, these TIDs were in the wake of the eclipse totality (lagging behind the umbra), and the wave period was shorter than the medium-scale or short-scale TIDs typically seen in the GPS TEC data. Finally, large reductions in TEC and ionospheric plasma densities (by 33%–45%) as a response to the eclipse were observed in both the GPS TEC and ionosonde data. The ionospheric density in the ionospheric E-region reached minimum roughly at the same time as the maximum eclipse, while the ionospheric F-region density and GPS TEC reached minimum 20–30 minutes after the maximum eclipse.