ALBERT

Description: All the accessible auroral observations recorded in Chinese and Japanese histories during the interval AD 1840–1911 are investigated in detail. Most of these auroral records have never been translated into a Western language before. The East Asian auroral reports provide information on the date and approximate location of each auroral observation, together with limited scientific information on the characteristics of the auroral luminosity such as colour, duration, extent, position in the sky and approximate time of occurrence. The full translations of the original Chinese and Japanese auroral records are presented in an appendix, which contains bibliographic details of the various historical sources. (There are no known reliable Korean observations during this interval.) A second appendix discusses a few implausible "auroral" records, which have been rejected. The salient scientific properties of all exactly dated and reliable East Asian auroral observations in the interval AD 1840–1911 are summarised succinctly. By comparing the relevant scientific information on exactly dated auroral observations with the lists of great geomagnetic storms compiled by the Royal Greenwich Observatory, and also the tabulated values of the Ak (Helsinki) and aa (Greenwich and Melbourne) magnetic indices, it is found that 5 of the great geomagnetic storms (aa〉150 or Ak〉50) during either the second half of the nineteenth century or the first decade of the twentieth century are clearly identified by extensive auroral displays observed in China or Japan. Indeed, two of these great storms produced auroral displays observed in both countries on the same night. Conversely, at least 29 (69%) of the 42 Chinese and Japanese auroral observations occurred at times of weak-to-moderate geomagnetic activity (aa or Ak≤50). It is shown that these latter auroral displays are very similar to the more numerous (about 50) examples of sporadic aurorae observed in the United States during the interval AD 1880–1940. The localised nature and spatial structure of some sporadic aurorae observed in East Asia is indicated by the use of descriptive terms such as "lightning", "rainbow", "streak" and "grid".

Description: Comprehensive catalogues of ancient sunspot and auroral observations from East Asia are used to identify possible intense historical geomagnetic storms in the interval 210 BC-AD 1918. There are about 270 entries in the sunspot catalogue and about 1150 entries in the auroral catalogue. Special databases have been constructed in which the scientific information in these two catalogues is placed in specified fields. For the purposes of this study, an historical geomagnetic storm is defined in terms of an auroral observation that is apparently associated with a particular sunspot observation, in the sense that the auroral observation occurred within several days of the sunspot observation. More precisely, a selection criterion is formulated for the automatic identification of such geomagnetic storms, using the oriental records stored in the sunspot and auroral databases. The selection criterion is based on specific assumptions about the duration of sunspot visibility with the unaided eye, the likely range of heliographic longitudes of an energetic solar feature, and the likely range of transit times for ejected solar plasma to travel from the Sun to the Earth. This selection criterion results in the identification of nineteen putative historical geomagnetic storms, although two of these storms are spurious in the sense that there are two examples of a single sunspot observation being associated with two different auroral observations separated by more than half a (synodic) solar rotation period. The literary and scientific reliabilities of the East Asian sunspot and auroral records that define the nineteen historical geomagnetic storms are discussed in detail in a set of appendices. A possible time sequence of events is presented for each geomagnetic storm, including possible dates for both the central meridian passage of the sunspot and the occurrence of the energetic solar feature, as well as likely transit times for the ejected solar plasma. European telescopic sunspot drawings from the seventeenth century are also used to assess the credibility of some of the later historical geomagnetic storms defined solely by the East Asian sunspot and auroral records. These drawings cast doubt on a few of the associations between sunspot and auroral observations based entirely on the oriental records, at least to the extent that the occidental drawings provide a more realistic date for central meridian passage of the sunspot actually associated with a particular auroral observation. Nevertheless, on those occasions for which European sunspot drawings are available, the dates of all the pertinent East Asian sunspot and auroral observations are corroborated, apart from just one Chinese sunspot observation. The ancient historical observations of sunspots and aurorae are discussed briefly in terms of modern observations of great geomagnetic storms.

Description: The Ballagan Formation (Late Tournaisian–Early Viséan) of central Scotland yields an ostracod fauna of 14 species in ten genera, namely Beyrichiopsis, Cavellina, Glyptolichvinella, Glyptopleura, Knoxiella, Paraparchites, Sansabella, Shemonaella, Silenites and Sulcella. The ostracods, in combination with palynomorphs, are important biostratigraphical indices for correlating the rock sequences, where other means of correlation, especially goniatites, conodonts, foraminifera, brachiopods or corals are absent. Stratigraphical distribution of the ostracods, calibrated with well-established palynomorph biozones, identifies three informally defined intervals: a sub-CM palynomorph Biozone interval with poor ostracod assemblages including Shemonaella scotoburdigalensis; a succeeding interval within the CM palynomorph Biozone where Cavellina coela, Cavellina incurvescens, Sansabella amplectans and the new species Knoxiella monarchella and Paraparchites discus first appear; and, an upper interval, in the upper CM Biozone, marked by the appearance of Sulcella affiliata. At least locally in central Scotland, S. affiliata permits a level of resolution equivalent to a sub-zonal upper division of the CM Biozone. The fauna, flora, sedimentology and stable isotope composition (δ13C and δ18O) of carbonate minerals in the Ballagan Formation suggest the ostracods inhabited brackish, hypersaline and ephemeral aquatic ecologies in a coastal floodplain setting.