Solar eclipse

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

Spatial and temporal patterns of solar eclipses by Phobos on Mars

Abstract: [1] The spatial and temporal patterns associated with motion of the shadow of Phobos across the surface of Mars are quite different than those associated with solar eclipses on Earth. We present a simple analysis of variations in the position, velocity, size, and shape of the shadow. Simple expressions give reasonably accurate depictions of the shadow motion, which mainly consists of a subdiurnal longitude cycle and an annual latitude cycle. Over most of each year, there are an average of 3.22 shadow transits per day. The duration of the shadow transit depends on latitude. It is maximum at the equator and is then 11.8% of the orbital synodic period. As the subsolar point moves north, the shadow moves south, and vice versa. There is a narrow band, centered on the equator of Mars, within which every point is eclipsed at least once during each semiannual eclipse season. Outside that band, the density of coverage decreases slowly with increasing distance from the equator, until the limiting latitudes are reached. During epochs, like the present, when the obliquity of Mars is in excess of 21.2°, there are portions of each year during which no eclipses occur. As the obliquity increases beyond that transition value, the durations of the eclipse seasons decrease. The minimum possible eclipse season duration, expressed as a fraction of the Mars year, is the same as the maximum shadow transit duration, expressed as a fraction of the Phobos synodic period, since both ratios depend on the same geometry, which is essentially just the radius of the orbit of Phobos, compared to the radius of Mars.

Effects of the 20 March 2015 solar eclipse in Strasbourg, France

Abstract: On 20 March 2015 a partial solar eclipse occurred at Strasbourg, France, with an obscuration of 72.4%. The consequences of this event were observed under optimal weather conditions with micrometeorological instruments. Among these, the global radiation deficit can be estimated to be of 1.724MJ per horizontal square meter. A modification of the solar spectrum with a greater proportion of photosynthetically active radiation was also observed. The extinction of the solar radiation resulted in a reduction of the net radiation, a sharp decrease in the surface temperatures and a change in all surface heat fluxes.

Ionospheric Effects of the Total Solar Eclipse of 16 Feb. 1980 Observed over Ahmedabad

Abstract: Ionosonde observations and Faraday rotation measurements were made at Ahmedabad to study the ionospheric effects of the total solar eclipse of 16 Feb. '1980. Data on the eclipse day and control day (mean for 17-19 Feb. 1980)are presented in a comparative way. Decrease in the critical frequencies of E-. F1and F2-layers, viz.foE,foFI and foF2 and in the minimum frequency f;";o detected by the ionosonde, associated with the eclipse are noted. True height analysis of the quarter hourly ionograms shows decreases in the electron densities at various heights, the effects being gradually delayed at higher altitudes. Increase in the height of maximum F2-1ayer ionization (hmF2) and in the semi-thickness of the F2-layer (Yml are noted. A decrease in the total electron content (TEC) derived from the recordings of Faraday rotation at Ahmedabad is found during solar eclipse. No evidence of gravity waves, generated due to the eclipse and propagating in the ionosphere, could be detected from the continuous recording of foF2 or TEe.