Eclipse Records Research Articles

The increasingly dominant role of climate change on length of day variations

The melting of ice sheets and global glaciers results in sea-level rise, a pole-to-equator mass transport increasing Earth's oblateness and resulting in an increase in the length of day (LOD). Here, we use observations and reconstructions of mass variations at the Earth's surface since 1900 to show that the climate-induced LOD trend hovered between 0.3 and 1.0 ms/cy in the 20th century, but has accelerated to 1.33 [Formula: see text] 0.03 ms/cy since 2000. We further show that surface mass transport fully explains the accelerating trend in the Earth oblateness observed in the past three decades. We derive an independent measure of the decreasing LOD trend induced by Glacial Isostatic Adjustment (GIA) of [Formula: see text]0.80 [Formula: see text] 0.10 ms/cy, which provides a constraint for the mantle viscosity. The sum of this GIA rate and lunar tidal friction fully explains the secular LOD trend that is inferred from the eclipse record in the past three millennia prior to the onset of contemporary climate change. Projections of future climate warming under high emission scenarios suggest that the climate-induced LOD rate may reach 2.62 [Formula: see text] 0.79 ms/cy by 2100, overtaking lunar tidal friction as the single most important contributor to the long-term LOD variations.

Eclipse Records Pin Dates of 12th and 13th Century Eruptions

Ancient accounts of dark and blood-red moons help scientists peek at past eruptions and their effect on global climate.

Analyses of historical solar eclipse records in Hokkaido Island in the 18–19th centuries

Abstract Solar eclipses have been recorded throughout history and across various ethnic groups. Their records have benefitted scientific discussions on multiple topics. These astronomical spectacles have also been recorded in the Japanese archipelago, but little has been known of the historical observations in the northern end: Hokkaido Island (known as Ezo Island until 1869). Here, we analysed three such early eclipse accounts from Hokkaido Island, both philologically and astronomically. We first analysed Tokunai Mogami's eclipse account written in 1786 January, which has been associated with the earliest eclipse record in Hokkaido Island. Our analysis showed that this eclipse was a deep partial solar eclipse outside the annular totality path of a hybrid eclipse, whereas it had previously been associated with an annular solar eclipse. This eclipse was also witnessed in the Ryukyu Kingdom, probably as a deep partial eclipse. We also located eclipse sketches in Kan’ichiro Mozume's diary and confirmed the local visibility of the annular eclipse in Otaru in 1872 June. We further analysed John Batchelor's eclipse folklore and identified the reported eclipse with a total solar eclipse in 1824 June. This folklore reported “tongues of fire and lightning” from the side of the “black dead sun.” This description is morphologically consistent with that of solar coronal streamers around the solar minima. This eclipse is chronologically located around the minimum of Solar Cycles 6/7 and contrasts the Dalton Minimum with the Maunder Minimum, for which coronal streamers were reportedly missing, according to visual observations.

The Variable Earth’s Rotation in the 4th–7th Centuries: New ΔT Constraints from Byzantine Eclipse Records

As one of the greatest astronomical spectacles, total solar eclipses have long been a subject of scientific interest and have been recorded by numerous civilizations over the millennia. These records are an essential reference for constraining and reconstructing Earth’s variable rotation (ΔT) prior to the 17th century. However, ΔT reconstructions for the 4th–7th centuries have significant uncertainties, mainly owing to a data scarcity. Here, we analyze Byzantine historical sources with reports of total solar eclipses along the Eastern Mediterranean coasts and add probable ΔT constraints on their basis. We examined five cases of total solar eclipses in 346, 418, 484, 601, and 693 CE, identified times and locations of the observations, and compared them with the existing ΔT spline curve to derive new ΔT constraints. Our results probably tighten ΔT variability in 346 CE, show a larger ΔT range in 418 CE, and give smaller ΔT ranges in 484, 601, and 693 CE. Our study tightens the existing ΔT variations and occasionally support some ΔT constraints that slightly depart from the ΔT spline curve in the latest reconstructions. Our results are consistent with contemporary ΔT constraints from other studies and offer an improved understanding of Earth’s variable rotation.

Analyses of a datable solar eclipse record in Maya Classic period monumental inscriptions

ABSTRACTHistorical records of total solar eclipses provide vital information for computing the rotation of the Earth and understanding its long-term variations in the time before modern measurements. While eclipses recorded around Eurasia and North Africa for millennia have been subjected to consideration in this context, eclipse records in the American continents have received little attention. In this study, we analysed the solitary observational record for a solar eclipse conducted by the ancient Maya on 790 July 16 in the Julian calendar, recorded on the Stela 3 of Santa Elena Poco Uinic (N16°35′, W91°44′). This stela has an eclipse glyph and is associated with a total solar eclipse. Taking the up-to-date Earth rotation (ΔT) rate into account, our calculations locate this site slightly out of the totality path. The visibility of the total solar eclipse from Santa Elena Poco Uinic would require ΔT to be 4074 s < ΔT < 4873 s. In comparison with the contemporary eclipse records, this yields a short-term increase in ΔT ≥ 800 s between 761 and 790 and a decrease in ΔT ≥ 580 s between 790 and 873. Therefore, the total solar eclipse on 790 July 16 cannot be expected to have been visible from Santa Elena Poco Uinic, unlike what has been previously considered. We conclude that this stela probably records a partial solar eclipse of great magnitude (≈0.946) visible under favourable meteorological conditions or is based on hearsay from the southern coastal area.

Astronomical Assessment of the Solar and Lunar Eclipse Records in Bede’s Ecclesiastical History and Its Continuation

The reports of seven eclipses of the Sun and Moon in Bede’s Ecclesiastical History and its Continuation are investigated for their astronomical accuracy using modern-day calculations. The eclipses can all be identified from the given dates, which are accurate to within 2 days, except for one lunar eclipse. There is evidence that the reports were obtained from a range of sources beyond the NE of England, two possibly from as remote as Rome. From the lack of physical detail, we deduce that the interest in the eclipses was their relevance to historical matters, rather than in the phenomena themselves.

The Case for the Lower Middle Chronology

Dendrochronological data and greater precision in the relative chronology between Babylonia and Assyria have led to the reopening of the discussion about Mesopotamian chronology in the 2nd millennium BC. The article makes four points. First, the arguments for the standard chronologies based upon the data of the Venus Tablets are robust. Counterarguments are found wanting. Second, once likely errors are taken into account, there is a natural recording procedure for which the Lower Middle Chronology is in accordance with the data. Third, among the four standard chronologies only the Lower Middle Chronology can easily satisfy the constraint provided by the eclipse record of the Mari Eponym Chronicle. Finally, this chronology is also in exact agreement with the widespread record of a volcanic eruption in 1628/27 BC.

ON THE RELIABILITY OF HAN DYNASTY SOLAR ECLIPSE RECORDS

The veracity of early Chinese records of astronomical observations has been questioned, principally based on two early studies from the 1950s, which suggested that political motives may have led scholar-officials at court to fabricate astral omens. Here I revisit the Han Dynasty (206 BCE-220 CE) solar eclipse reports to determine whether the charge has merit for those first four centuries of the imperial period. All 127 dated solar eclipses reported in the official sources are checked for accuracy against the Five Millennium Catalog of Solar Eclipses produced by Espenak and Meeus (2009). The Han Dynasty records prove remarkably accurate. Copyists errors do occur, but there are only rare instances of totally erroneous reports, none of which is provably the result of politically- motivated manipulation.

Directions of Obscuration in Babylonian Eclipse Records

This paper evaluates the question in which coordinate system the reported entrance and exit directions of the shadow were given in Babylonian eclipse records. It turns out that the angles were measurend in a simplified ecliptic coordinate system. For the determination of ecliptic position angles it is necessary to know the true northern point of the lunar or solar limb. A method using the distinctive features on the Moon is proposed for determing this true northern point.

A Study of Solar Eclipse Records during the Three Kingdoms Period in Korea

In this study, solar eclipse records were investigated during the Three Kingdoms era of ancient Korea using astronomical calculations and numerical simulations. Under the condition that the solar eclipses were actually observed at the well known capitals of the Three Kingdoms, I investigated the probabilities that the optimal observation areas of the Early Silla, Goguryeo, and Baekje records would appear around Chinese continent. I found higher probabilities than those suggested by Park and La (1994), although the numerical values are still low, especially in the case of the Early Silla records. On the other hand, the probability that the optimal observation area of the Later Silla records will be present around South Korea is only 13.6%, although the area shows a good match with the known capital. I also analyzed the number distribution of the eclipse records for the Three Kingdoms (except for the latter Silla's) according to the observers' locations: at the optimal observation areas and at the known capitals. And then I compared with the number distribution of all eclipses observable from those locations. From the <TEX>$\chi^2$</TEX>-test, I found that the Goguryeo and Baekje records had better representation of their population distributions at the latter regions (<TEX>$\chi^2$</TEX>=27.93 and 205.5) than at the former ones (<TEX>$\chi^2$</TEX>=34.19 and 211.5). Therefore, it is difficult to conclude that the observers' locations during the Three Kingdoms period were either near China, as suggested by Park and La, or in the Korean peninsula, solely based on these results. It is thus recommended that more studies are required to confirm the real observers' locations during the Three Kingdoms era.

Book Review: Babylonian Eclipse Records: Babylonian Eclipse Observations from 750 BC to 1 BC

Book Review: Babylonian Eclipse Records: Babylonian Eclipse Observations from 750 BC to 1 BC

An Ancient Solar Eclipse Record ``Tian-da-yi'' in the 10th Century BC

The ancient record ``Tian-da-yi'' (the sky darkened greatly) is identified with the solar eclipse on May 31, 976BC. This identification is demonstrated in this paper through a palaeographic, astronomical and chronological analysis. It is probably the earliest solar eclipse in Chinese history that can be so identified.

Anthropogenic signals recorded in an ice core from Eclipse Icefield, Yukon Territory, Canada

Trends in the annual flux of sulfate and nitrate in a new ice core collected at an elevation of 3017 m on Eclipse Icefield, 45 km northeast of Mt. Logan were examined to determine the effect of anthropogenic activity on precipitation chemistry in the remote northwest North America mid‐troposphere. The annual flux of both sulfate and nitrate at Eclipse began increasing in the 1940s, demonstrating, for the first time, the anthropogenic sulfate and nitrate pollution of the northwest North American Arctic in an ice core from this region. Comparison of the Eclipse record with regional emission estimates for total sulfur and nitrogen oxides suggests that Eurasia is the dominant source of pollutants reaching Eclipse. The available data does not permit a confident assessment of the relative importance of European versus Soviet emissions in producing the observed trends in sulfate and nitrate at Eclipse.

Eclipse Records in Early Korean History: The Koryo-sa

The following is a summary of recent research which I have undertaken on the eclipse records in the Koryo-sa. This work is based on a careful examination of the astrological treatise of the Koryo-sa. I have compared each of the many solar and lunar eclipse accounts with the results of computation and based deductions on these comparisons.

Records of lunar eclipses in medieval Arabic chronicles

In a previous paper, we discussed a series of solar eclipse observations recorded in medieval Arabic chronicles both for their astronomical and chronological value. In the present paper we investigate lunar eclipses reported in these same sources as well as in many further chronicles. It should be stressed that our interest here is limited to eclipse records from chronicles; we have not included any material from technical treatises composed by astronomers. The observations are largely from al-Andalus (Islamic Spain), Egypt, Iraq, and Syria; they mainly cover the date range from A.D. 867 to 1520, with additions from 1674 to 1791.

Long-term fluctuations in the Earth’s rotation: 700 BC to AD 1990

Records of solar and lunar eclipses in the period 700 BC to AD 1600, originating from the ancient and medieval civilizations of Babylon, China, Europe and the Arab world, are amassed and critically appraised for their usefulness in answering questions about the long-term variability of the Earth’s rate of rotation. Results from previous analyses of lunar occupations in the period AD 1600-1955.5, and from high-precision data in AD 1955.5-1990, are included in the dataset considered in this paper.

The earliest known solar eclipse record redated

AN astronomical event recorded on a clay tablet found in 1948 among the ruins of the ancient city of Ugarit, in what is now Syria, was identified 20 years ago as a description of a total solar eclipse that occurred on 3 May 1375 BC1,2. The dating of ancient solar eclipses provides reference points to fix the long-term evolution of angular momentum in the Earth-Moon system3. We have reanalysed the Ugarit eclipse record4. A new historical dating of the tablet, and mention in the text of the visibility of the planet Mars during the eclipse as well as the month in which it occurred enables us to show that the recorded eclipse in fact occurred on 5 March 1223 BC. This new date implies that the secular deceleration of the Earth's rotation has changed very little during the past 3,000 years.

Records of solar eclipses in Arabic chronicles

Of the many astronomical observations which are recorded in ancient and medieval history, perhaps the most interesting and useful relate to solar eclipses. Obscurations of the Sun are often noticed by the casual observer and may indeed leave a profound impression on him if the degree of obscuration of the Sun is very large. In particular, total solar eclipses are responsible for the onset of sudden and intense darkness, during which the brighter planets and stars may become visible. Hence ancient and medieval accounts of solar eclipses (and to a lesser extent lunar obscurations) are not confined to treatises on astronomy. They also tend to be reported fairly frequently in chronicles and other writings of a historical nature. The only other celestial phenomena regularly to attract widespread attention in ancient and medieval times were comets. However, in chronological studies, eclipses have a distinct advantage over comets. Both solar and lunar obscurations last for only a few hours and their exact date of occurrence can be computed, as well as the time of day (or night) when the event took place. Comets, on the other hand, often remain visible for several weeks and only for Halley's Comet can useful computations of visibility be made.

Joint use of eclipse records in China, Japan and Korea for the study of the earth's paleorotation

It has become a new field to use the ancient records of astronomical phenomena for studying the secular change of the earth's rotation. China is very rich in ancient astronomical observations, to which much attention has been given recently. But the continuum of the observational series is affected critically by gaps with lengths of over half a century (TABLE 1). TABLE 1Gaps in the Time Records of Eclipses in Ancient China and Their Remedy with Ones from Japan/KoreaNo.GapDuration (in yrs)Number of J-K recordsMean frequency/10 yr.1BC145--1341112BC134--89453BC89--34554BC28--AD61885AD61--175114(5)0.56AD223--31188(2)0.27AD311--429118(2)0.28AD546--680134(3)0.29AD794--84046(5)1.110AD840--94010090.911AD959--10408191.112AD1302--1450148332.213AD1450--1572122433.514AD15781687829211.2Note: The numbers in brackets refer to the available records of the central eclipse in Japan and Korea.China, Japan and Korea are close neighbours, either adjacent to each other, or separated by a sea, and have a long history of contact and exchange in culture and science. Their ancient astronomies are similar in many aspects, and their astronomical records may be regarded as a unit. Japan and Korea have also accumulated a wealth of ancient records in astronomy, including 232 time observations from AD 840 to 1639 and 149 records of central eclipses from AD 61 to 862 (TABLE 2). However, they have not been utilized in this field. The author has especially analyzed the records of the central eclipse and eclipse time of these three countries, compared their respective merits and shortcomings, and concluded that their joint use may compose a valuable record series for the study of the earth's rotation. This work could change the situation of neglect of the ancient records of east Asia in this field. From TABLE 3 it may be seen that the united series of records are more excellent than any others. TABLE 2Comparision Between the Records of Central Eclipses in Ancient China, Japan and Korea (by the end of AD 862)ContentChinaJapanKoreaMost ancient recordBC 776 Sept. 6 (Total)AD 628 Apr. 10 (Total)BC 54 May 9 (Total)Number of solar eclipses41513467Number of central eclipses36311138Number of the available eclipse973510The ancient records of astronomical phenomena may also be used to study the evolution of the Earth-Moon system and to test the theoritical predictions of general relativity. The author has completed the analyses of the records of eclipse time, equinox time and the central eclipse, and points out that China, Japan and Korea have the potential for studying this subject. Our hope is laid on the new development of archaeology of remote ages and inscriptions on hones of the Shang Dynasty, and on interdisciplinary cooperation. TABLE 3Time Records of the Eclipse Left over by the Ancient Civilizations of the WorldRegionTime-intervalDurationNumber of recordsMean fr. per 10 yrsBabylonia & AssyriaBC 721--382349110.3Greek(Mediterranean)BC 201--AD346560100.2East AsiaBC 145--AD163018004202.1IslamAD 829--1004175331.9European?Note: The eclipse records in the inscriptions on bones of China are not included in this census.

春秋時代(B.C.722〜479)の日食その他天文記事の再検討

春秋時代(B.C.722〜479)の日食その他天文記事の再検討