From "Periodical Observations” to "Anthochronology” and "Phenology” - the scientific debate between Adolphe Quetelet and Charles Morren on the origin of the word "Phenology”

Mankind has observed and documented life cycle stages of plants and animals for a long time. However, it was comparatively recently that the newly emerging science was given its name. The name of Charles Morren and the year 1853 are being cited, although not frequently. Exact information is hardly known among present-day phenologists, yet new evidence shows that the term "phenology” was already in use in 1849. In the early 1840s, physicist and astronomer Adolphe Quetelet set up an observational network named "Observations of periodical Phenomena of the Animal and Vegetable Kingdom” and issued instructions for it. Even though biologist Charles Morren welcomed Quetelet's initiative, differences between Morren and Quentlet regarding the instructions for the observations and the potential results soon arose and a debate started, which lasted for nearly 10years. In the wake of these disagreements, Morren was compelled to create a new term to denote his ideas on "periodical phenomena”. At first, he temporally used the word anthochronology, but in the end he coined the word phenology. The term was first used in a public lecture at the Académie royale des Sciences, des Lettres et des Beaux-Arts de Belgique' in Brussels on 16 December 1849, and simultaneously in the December 1849 issue of volume V of the Annales de la Société royale d'Agriculture et de Botanique de Gand. One had to wait until 1853 before the new name appeared in the title of one of Morren's publications. Based on evidence from archives and original publications, we trace the 10-year-long scientific debate between Morren and Quetelet. Morren states his biologist's view on the subject and extends the more climate-related definition of Quetelet of "periodical phenomena

La sécheresse sahélienne pourrait s'être terminée durant les années 1990

peer reviewedThe severe drought that affects the Sahel since the late 1960s has been very closely studied and monitored during the last three decades. Recently, after several wet years, it was questioned from a statistical point of view whether the drought was over. The conclusions of a recent study were that the rainfall deficit was not over at the end of 2000 and that the drought continues. The analysis of the change points in the station rainfall time series suggests differentiating these findings. There is now growing evidence that there is a potential shift towards a more humid state. However, the present analysis shows that the assumption that a significant increase in rainfall may have occurred around the early 1990s could only be verified at the customary confidence level in about 10 years from now.La sécheresse qui touche la région sahélienne depuis la fin des années soixante a été extrêmement bien étudiée et suivie au cours des trois dernières décennies. Récemment, à la suite de quelques années fortement pluvieuses, certaines recherches ont été menées pour tenter de voir si cette sécheresse était statistiquement terminée. Les conclusions d’une récente étude montrent que ce déficit pluviométrique n’est pas terminé en fin 2000 et que la sécheresse continue. Sur la base de l’analyse de la première rupture pluviométrique, nous pensons qu’il est nécessaire de nuancer ces propos. Plusieurs signes suggèrent qu’une tendance vers une période plus humide pourrait s’être amorcée aux alentours des années 1990. Cependant, la continuité de la période de sécheresse ou l’identification d’une rupture pluviométrique vers des conditions plus humides ne pourra se vérifier statistiquement que dans une dizaine d’années

Origins of the word "phenology"

Observing and documenting life cycle stages of plants and animals have been tradition and necessity for humans throughout history. Phenological observations—as called by their modern scientific name—were key to successful hunting and farming because the precise knowledge of animal behavior and plant growth, as well as their timing with changing seasons, was critical for survival. In today's context of environmental awareness and climate change research, phenological observations have become prime indicators of documenting altered life cycles due to environmental change in disciplines from biology to climatology, geography, and environmental history. Observations on the ground, from space, and from models of different complexity describe intra-annual and interannual changes of life cycles at individual, pixel, or grid box scale

Walthère Victor Spring – A Forerunner in the Study of the Greenhouse Effect

: In 1886, an article by Walthère Spring and Léon Roland, two scientists from the University of Liège, dealing with the carbon dioxide content in the atmosphere in Liège appeared in the “Mẻmoires” of the Royal Academy of Belgium. In order to explain the difference between temperatures in the city of Liège and those observed in that city’s environs, the authors invoked the high level of atmospheric CO2. Although the climatological argument was rather weak and the article concerned only a local impact, it is obvious that Spring can be viewed as a precursor of Svante Arrhenius who foresaw global warming in 1895–1896

The eruption of Lakagígar in Islande or 'Annus Mirabilis 1783' – Chronicle of an extraordinary year

Durant l’année 1783, un grand brouillard sec enveloppa l’Hémisphère Nord pendant plusieurs mois. A l’origine de celui-ci, l’éruption volcanique du Lakagígar en Islande qui débuta le 8 juin 1783. La nouvelle de cette éruption ne fut connue à Copenhague qu’au 1er septembre 1783 ; elle fut ensuite répercutée, dans le reste de l’Europe, par le courrier des gazettes. Les naturalistes européens étaient dans l’ignorance complète quant à l’origine du phénomène. Cependant, comme l’année 1783 fut très riche en phénomènes météorologiques, hydrologiques, géophysiques et épidémiques, ils ne manquèrent pas d’y trouver là une explication. Les scientifiques de l’époque répondirent par des interprétations se rattachant à la théorie, déjà dépassée, de la Meteorologica d’Archimède ou bien à des théories nouvelles comme l’électricité atmosphérique.Benjamin Franklin fut un des premiers scientifiques à établir la relation entre l’éruption volcanique et l’hiver long et rude qui a suivi. L’hypothèse selon laquelle il y aurait une relation potentielle entre l’éruption du Lakagígar et le niveau du Nil au Caire, en Egypte, est discutée. Il s’avère plutôt que les phénomènes météorologiques et hydrologiques de l’année 1783 s’inscrivent tout à fait dans le cadre d’un événement ENSO chaud pluriannuel.During 1783 a Great Dry Fog (GDF) enveloped the Northern Hemisphere for several months. The origin of this was the fissure eruption associated with the volcano Laki in Iceland which began on 8 June 1783. However, news of the eruption did not reach Europe until 1 September 1783 when ships from Iceland reached Copenhagen. News then spread to the rest of Europe where scientists had not known the exact origin of the fog. As there had been so many recent events in the form of meteorological, hydrological, and geophysical phenomena, as well as many epidemics, many explanations had been offered for it. At that time, scientists responded in line with the classical, but already outmoded, theory of Archimedes’ Meteorologica, as well as new ideas regarding electricity in the atmosphere. Benjamin Franklin was one of the first scientists to establish the connection between a volcanic eruption and a long and severe winter following this. The hypothesis that there is a connection between the Lakagígar eruption and the level of the Nile River in Egypt will be discussed. In this regard, the meteorological and hydrological phenomena of the year 1783 may be seen in the context of a multi-year warming ENSO event

Weather typing based flood frequency analysis validated for exceptional historical events of past 500 years along the Meuse river

Governments, policy makers, and water managers are pushed by recent socioeconomic developments such as population growth and increased urbanization inclusive of occupation of floodplains to impose very stringent regulations on the design of hydrological structures. These structures need to withstand storms with return periods typically ranging between 1,250 and 10,000 years. Such quantification involves extrapolations of systematically measured instrumental data, possibly complemented by quantitative and/or qualitative historical data and paleoflood data. The accuracy of the extrapolations is, however, highly unclear in practice. In order to evaluate extreme river peak flow extrapolation and accuracy, we studied historical and instrumental data of the past 500 years along the Meuse River. We moreover propose an alternative method for the estimation of the extreme value distribution of river peak flows, based on weather types derived by sea level pressure reconstructions. This approach results in a more accurate estimation of the tail of the distribution, where current methods are underestimating the design levels related to extreme high return periods. The design flood for a 1,250 year return period is estimated at 4,800 m3 s−1 for the proposed method, compared with 3,450 and 3,900 m3 s−1 for a traditional method and a previous study.status: publishe

Flood frequency analyses and the added value of historical datasets: case study for the Meuse River basin (1500 – 2015)

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