Solar eclipse

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

Near-infrared observation of the circumsolar dust emission during the 1983 solar eclipse

Abstract: A near-infrared excess emission superposed on the coronal continuum at ∼4R⊙ from the Sun was first observed at 2.2 µm by Peterson1 and MacQueen2 during the total solar eclipse in 1966, and was later confirmed by MacQueen2 using a balloon-borne coronagraph. Two subsequent observations were made; one3 obtained a similar result, while the other4 detected no excess emission. The excess emission was thought to be due to thermal radiation by a dust cloud around the Sun, and interpreted to be interplanetary dust2. Brecher et al.5, on the other hand, have proposed that the ring is composed of much larger objects (of about 10 km diameter). To obtain more definite information, we have therefore carried out observations of near-infrared brightness distributions of the solar corona, using a balloon-borne photometer at a balloon altitude, during the total eclipse on 11 June 1983 in Indonesia. As we report here, emissions in excess of the strong coronal background emission were recorded in some of the scans at ∼4R⊙ from the Sun. The spatial distribution of the excess emission implies the existence of a circumsolar ring of dust lying approximately in the ecliptic plane.

Development of meteorological parameters and total ozone during the total solar eclipse of August 11, 1999

Abstract: 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) in the wavelength pairs used to calculate total ozone. However, there also appeared to be real fluctuations in total ozone during the reemerging phase of the sun which may be related to eclipse induced gravity waves.

Structure and dynamics of the 2009 july 22 eclipse white-light corona

Abstract: The white-light corona (WLC) during the total solar eclipse of 2009 July 22 was observed by several teams in the Moon's shadow stretching from India and China across the Pacific Ocean with its many isolated islands. We present a comparison of the WLC as observed by eclipse teams located in China (Shanghai region) and on the Enewetak Atoll in the Marshall Islands, with observations taken 112 minutes apart, combined with near-simultaneous space observations. The eclipse was observed at the beginning of solar cycle 24, during a deep solar minimum (officially estimated as 2008 December according to the smoothed sunspot number, but very extended). The solar corona shows several different types of features (coronal holes, polar rays, helmet streamers, faint loops, voids, etc.), though it was extremely sparse in streamers as shown from Large-Angle Spectroscopic Coronagraph data. No large-scale dynamical phenomena were seen when comparing the observations from the two sites, confirming that the corona was quiescent. We measure a Ludendorff flattening coefficient of 0.238, typical of solar minimum.