https://hal-mines-paristech.archives-ouvertes.fr/docs/00/72/59/87/PDF/Solar_Energy-SG2_Article_accepted-version.pdf

The SG2 algorithm for a fast and accurate computation of the position of the Sun for multi-decadal time period

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.

Solar eclipses as an astrophysical laboratory

The occasion of the longest totality of an eclipse in the 18 yr 11⅓ 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.

https://iopscience.iop.org/article/10.1088/1674-4527/9/6/001/pdf

Scientific observations at total solar eclipses

[1] The Moon cast a long shadow over Antarctica on 23 November 2003 in a total solar eclipse. The eclipse was observed at Dome Fuji Station, located at the highest point of East Dronning Maud Land, Antarctica, and lasted 1 h 41 min 37 s in a cloudless condition, during which the Sun was completely obscured for 1 min 43 s. This was the first total solar eclipse to be observed in the Antarctic ice sheet. During the eclipse at Dome Fuji, the air temperature at 1.5 m above the snow surface and the subsurface snow temperature decreased by 3.0 K and 1.8 K, respectively. Estimated surface snow temperatures decreased by 4.6 K. Atmospheric pressure and wind direction did not change, but the wind speed possibly decreased by 0.3 m/s with decreasing air temperature; natural variations in wind speed before and after the eclipse made it difficult to identify a true effect of the solar eclipse. Variations of energy components (net shortwave and longwave radiations, sensible and latent heat fluxes, and geothermal heat) during the eclipse were investigated. The total loss of global solar radiation during the eclipse was 0.60 MJ m−2, equaling 1.6% of the total daily global solar radiation. Regional effects of the eclipse due to a reduction of global solar radiation for air temperature and snow temperature ranged from 0.015 to 0.020 K (W m−2)−1. We additionally examined the relation between eclipse obscuration (the fraction of the Sun's surface area occulted by the Moon) and the reduction of global solar radiation from the first to second contacts. The eclipse was also observed from space by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard NASA's Terra and Aqua satellites. The observational results of this study will contribute to detailed model calculations for clarifying the meteorological effects of eclipses.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2009JD011886

Total solar eclipse over Antarctica on 23 November 2003 and its effects on the atmosphere and snow near the ice sheet surface at Dome Fuji

Recently revised ice core chronologies for Greenland have newly identified one of the largest sulfate deposition signals of the last millennium as occurring between 1108 and 1113 CE. Long considered the product of the 1104 CE Hekla (Iceland) eruption, this event can now be associated with substantial deposition seen in Antarctica under a similarly revised chronology. This newly recognized bipolar deposition episode has consequently been deemed to reveal a previously unknown major tropical eruption in 1108 CE. Here we show that a unique medieval observation of a “dark” total lunar eclipse attests to a dust veil over Europe in May 1110 CE, corroborating the revised ice-core chronologies. Furthermore, careful evaluation of ice core records points to the occurrence of several closely spaced volcanic eruptions between 1108 and 1110 CE. The sources of these eruptions remain unknown, but we propose that Mt. Asama, whose largest Holocene eruption occurred in August 1108 CE and is credibly documented by a contemporary Japanese observer, is a plausible contributor to the elevated sulfate in Greenland. Dendroclimatology and historical documentation both attest, moreover, to severe climatic anomalies following the proposed eruptions, likely providing the environmental preconditions for subsistence crises experienced in Western Europe between 1109 and 1111 CE.

/pdf/climatic-and-societal-impacts-of-a-forgotten-cluster-of-2j2iex542x.pdf

Climatic and societal impacts of a “forgotten” cluster of volcanic eruptions in 1108-1110 CE

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).

Jean Meeus

Papers

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