60 research outputs found

    Instrumental and Observational Problems of the Earliest Temperature Records in Italy: A Methodology for Data Recovery and Correction

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    A distinction is made between data rescue (i.e., copying, digitizing, and archiving) and data recovery that implies deciphering, interpreting, and transforming early instrumental readings and their metadata to obtain high-quality datasets in modern units. This requires a multidisciplinary approach that includes: palaeography and knowledge of Latin and other languages to read the handwritten logs and additional documents; history of science to interpret the original text, data, and metadata within the cultural frame of the 17th, 18th, and early 19th centuries; physics and technology to recognize bias of early instruments or calibrations, or to correct for observational bias; and astronomy to calculate and transform the original time in canonical hours that started from twilight. The liquid-in-glass thermometer was invented in 1641 and the earliest temperature records started in 1654. Since then, different types of thermometers have been invented, based on the thermal expansion of air or selected thermometric liquids with deviation from linearity. Reference points, thermometric scales, and calibration methodologies were not comparable, and not always adequately described. Thermometers had various locations and exposures, e.g., indoor, outdoor, on windows, gardens or roofs, facing different directions. Readings were made only one or a few times a day, not necessarily respecting a precise time schedule: this bias is analysed for the most popular combinations of reading times. The time was based on sundials and local Sun, but the hours were counted starting from twilight. In 1789–1790, Italy changed system and all cities counted hours from their lower culmination (i.e., local midnight), so that every city had its local time; in 1866, all the Italian cities followed the local time of Rome; in 1893, the whole of Italy adopted the present-day system, based on the Coordinated Universal Time and the time zones. In 1873, when the International Meteorological Committee (IMC) was founded, later transformed into the World Meteorological Organization (WMO), a standardization of instruments and observational protocols was established, and all data became fully comparable. In dealing with the early instrumental period, from 1654 to 1873, the comparison, correction, and homogenization of records is quite difficult, mainly because of the scarcity or even absence of metadata. This paper deals with this confused situation, discussing the main problems, but also the methodologies to recognize missing metadata, distinguish indoor from outdoor readings, correct and transform early datasets in unknown or arbitrary units into modern units, and, finally, in which cases it is possible to reach the quality level required by the WMO. The aim is to explain the methodology needed to recover early instrumental records, i.e., the operations that should be performed to decipher, interpret, correct, and transform the original raw data into a high-quality dataset of temperature, usable for climate studies

    DOCU-CLIM: A global documentary climate dataset for climate reconstructions

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    Abstract Documentary climate data describe evidence of past climate arising from predominantly written historical documents such as diaries, chronicles, newspapers, or logbooks. Over the past decades, historians and climatologists have generated numerous document-based time series of local and regional climates. However, a global dataset of documentary climate time series has never been compiled, and documentary data are rarely used in large-scale climate reconstructions. Here, we present the first global multi-variable collection of documentary climate records. The dataset DOCU-CLIM comprises 621 time series (both published and hitherto unpublished) providing information on historical variations in temperature, precipitation, and wind regime. The series are evaluated by formulating proxy forward models (i.e., predicting the documentary observations from climate fields) in an overlapping period. Results show strong correlations, particularly for the temperature-sensitive series. Correlations are somewhat lower for precipitation-sensitive series. Overall, we ascribe considerable potential to documentary records as climate data, especially in regions and seasons not well represented by early instrumental data and palaeoclimate proxies

    Impact of long-term (1764-2017) air temperature on phenology of cereals and vines in two locations of northern Italy

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    Understanding how long-term temperature variability affects the phenology of the main agricultural crop is critical to develop targeted adaptation strategies to near and far future climate impacts. The objective of this study was to use crop phenology as a proxy to quantify the impact of a long-term temperature variability series (1764-2017) on a summer cereal crop (maize), spring wheat, winter wheat, and four different vines (perennials) in two locations representative of the main agricultural areas in northern Italy. To develop the phenological models for cereals and grapevines, the minimum (TDmin) and maximum (TDmax) daily temperatures for Milano and Bologna, northern Italy, from 1763 to 2017 were used. Results showed that wheat (spring and winter) has experienced a reduction in the growing period of 13 days for each °C of air temperature increase during the growing season. Vernalization requirements of winter wheat indicated that further increase in air temperature will determine a shift towards a supraoptimal range. The subsequent delay in vernalization fulfilment causes the grain filling phase to occur in warmer conditions and will be further shortened with consequences for final yield. Chilling accumulation in vines was fulfilled over the entire period under study with 90% effective chilling. Highlights - Long-term weather series show how the mean air temperature and its extremes have changed over the years. - Simulation of cereals and perennials phenology using long-term weather series showed a shortening of the growing season and a shift of developmental stages. - The number of days when the air temperature is above the crops' physiological threshold increased, with implications for development and senescence rates

    A comparison between different methods to fill gaps in early precipitation series

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    The aim of this work is to analyse and compare different methodologies to fill gaps in early precipitation series, and to evaluate which time resolution is reachable, i.e. monthly or daily one. The following methods are applied and tested to fill the 1764–1767 gap in the precipitation series of Padua: (1) using a relationship between monthly amounts and frequencies; (2) transforming a daily log with visual observations into numerical values through analysis, classification, and calibration; (3) substituting the missing values with an instrumental record from a nearby, contemporary station in the same climatic area. To apply the second method, the descriptions reported in the Morgagni Logs are grouped in 37 classes and transformed into numerical values, using for calibration the observed amounts in the Poleni record over the 24-year common period. As a third method, the series of Temanza and Pollaroli in Venice is used to fill the gap, and the application of a factor scale based on the ratio Padua/Venice tempted. The results of these three methods are discussed and commented

    The Gondola: a boat to respond to the history, and the morpho-dynamics of the Venice Lagoon

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    Origin and evolution of the gondola have been reconstructed from historical and documentary written and pictorial sources (figures in books, engravings and paintings), in relation to the physical environment of the Lagoon, its morpho-dynamics with shallow and deep waters, marshes and channels. Particular care has been applied to the physical and hydrodynamic aspects in order to interpret the data and understand how the ancient Venetians could have had an advanced knowledge of the tidal range from sea stairs, tidal phase from the algae colour and direction, bottom depth from surface ripples, and exchanges between the Lagoon and the sea from suspended debris. The various elements of the boat are considered in terms of use and physical advantage, e.g. rowing style, cabin, hull and decorations. The boat evolution has been followed and documented over the centuries. This study clarifies the original shape of the gondola in the 11th century, from the analysis of the contemporary manuscripts and Byzantine mosaics in Ravenna and Venice, and a tablet of the early 14th century. In the 16th century, the gondola changed shape and size. The reason of this restyling was unknown, but has been found in the contemporary edicts, diaries and chronicles and other historical sources. The transformation was kept as a military secret, as well the production of a fleet of small boats provided of rostrums to sail on the rivers Po and Adige and fight against Ferrara and its Allies of the League of Cambrai. A comparison with the Viking- Norman vessels of Bayeux, Palermo and some codices show several strong analogies with the military gondolas of the 16th century. An overview of the written and pictorial sources has allowed to classify the various gondola types and recognize several technical details. Finally, the size and depth have been considered to interpret the ancient chronicles that mentioned that in the occasion of the most extreme storm surges, the gondolas could ride on San Marco Square, i.e. the flooding water depth necessary to float and to navigate over street paving.L'origine et l'évolution de la gondole vénitienne ont été reconstituées à partir de sources écrites et picturales historiques et iconographiques (figures de livres, gravures et peintures), en relation avec l'environnement physique de la lagune de Venise, en particulier sa morphodynamique caractérisée par des eaux de profondeurs variables et la présence de marais et de canaux. Un soin particulier a été porté aux aspects hydrodynamiques afin d'interpréter les données et de comprendre comment les anciens Vénitiens avaient une connaissance avancée de l'amplitude des marées par l’observation des escaliers marins, de la phase des marées grâce à la direction des algues, la profondeur des fonds lagunaires ou les échanges entre la lagune et la mer à partir des débris en suspension. Les différents éléments de la gondole sont analysés en termes d'utilisation et d'avantage, par ex. le style d'aviron, la cabine, la coque ou les décorations. L'évolution du bateau a été suivie et documentée au fil des siècles. Cette étude précise la forme originale de la gondole au XIe siècle, à partir de l'analyse de manuscrits contemporains, des mosaïques byzantines de Ravenne et de Venise et d'une tablette du début du XIVe siècle. Au XVIe siècle, la gondole change de forme et de taille. La raison de cette transformation était inconnue, mais a été retrouvée dans les édits contemporains, les journaux, les chroniques et d'autres sources historiques. La transformation fut gardée comme un secret militaire, ainsi que la production d'une flotte de petits bateaux munis de rostres pour naviguer sur le Pô et l’Adige et lutter contre Ferrare et ses alliés de la ligue de Cambrai. Une comparaison avec les navires vikings-normands de Bayeux, de Palerme et certains codex montrent plusieurs analogies fortes avec les gondoles militaires du XVIe siècle. Un aperçu des sources écrites et picturales a permis de classer les différents types de gondole et de reconnaître plusieurs détails techniques. Enfin, la taille et la profondeur ont été prises en compte pour interpréter les anciennes chroniques qui mentionnaient qu'à l'occasion des ondes de tempête maximales, les gondoles pouvaient naviguer sur la place Saint‑Marc, permettant d’estimer la profondeur d'eau nécessaire pour flotter dans les rues

    Galileo’s revolution and the infancy of meteorology in Padua, Florence and Bologna

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    This article reconstructs the historical and scientific framework within which modern science, and meteorology in particular, were born and developed beginning in the late XVI century. Scientific knowledge during this period was based on Aristotle’s books and the Holy Bible, and this constituted a serious obstacle for the new astronomical discoveries that contradicted this framework. The paper starts with the earliest experiments made by Galileo, his discoveries, e.g. thermoscope, telescope, solar spots and motion that caused his trial. Galileo facilitated the transition from the middle age to modern science, fighting against the old ideas and separating faith from research. The new science had a strong development with Ferdinand II, grand Duke of Tuscany who founded the Accademia del Cimento (i.e. Experiment Academy), and the first international network of temperature observations in the mid XVII century. The passage from the thermoscope to the modern thermometer is also explained, as well as the pioneering activity at the Universities of Padua and Bologna, and in Florence.Cet article traite de l’histoire, du contexte scientifique et du développement de la météorologie au XVI° siècle. À cette époque, les connaissances scientifiques étaient basées sur les ouvrages d’Aristote et sur la Bible, à l’origine de sérieux obstacles pour le développement de nouvelles découvertes astronomiques contredisant ces écrits. Cet article analyse les premières expériences de Galilée et de ses découvertes comme le thermoscope ou le télescope. Galilée a facilité la transition du Moyen Âge vers la science moderne, s’opposant aux postulats archaïques et séparant la science de la foi. Cette nouvelle science s’est particulièrement développée sous le règne de Ferdinand II, grand duc de Toscane, qui a fondé l’Accademia del Cimento (i.e. l’Académie des expériences) et le premier réseau international de collecte des températures. Nous expliquons aussi le passage du thermoscope au thermomètre et les activités pionnières des universités de Padoue, Bologne et Florence en Italie

    A relationship between temperature, oxygen dissolved in blood and viral infections

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    An investigation is made on the environmental factors that may determine the seasonal cycle of respiratory affections. The driving role of temperature is examined, for its inverse synergism with the dissolution of oxygen in human plasma. Two best-fit equations are discussed to interpolate the experimental data about the oxygen solubility and the saturation levels reached at various temperatures, referring to the value of the basic alveolar temperature. A vulnerable condition is when the airways temperature is lowered, e.g. breathing cold air, or increasing the breathing frequency. In winter, the upper airways reach lower temperatures and greater oxygen concentrations; the opposite occurs in summer. As low temperatures increase the dissolution of oxygen in plasma, and blood oxidation favours viral activity, an explanation is given to the seasonality of infections affecting the respiratory system

    Sperimentazione di uno strumento per la misura dell’umidità relativa in ambienti ad elevata umidità

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    La misura accurata dell’umidità relativa (UR) dell’aria e delle sue fluttuazioni in ambienti ipogei, come ad esempio le catacombe, è particolarmente complessa, giacché questi ambienti sono caratterizzati da elevati valori di UR (>85%). I sensori capacitivi a film sottile, comunemente impiegati nella misurazione di UR in ambiente interno, operano al meglio delle loro prestazioni per valori di UR tra il 30% e il 70% con incertezza associata tra ±1% e ±3%, a seconda del modello. Tuttavia, negli ipogei, un ulteriore fattore di rischio nella misura di UR è la formazione di uno strato sottile di acqua per condensazione sul materiale dielettrico, che contribuisce alla diminuzione delle prestazioni del sensore. Scopo del presente contributo è di mostrare i risultati preliminari della sperimentazione di un nuovo strumento per la misura dell'umidità relativa in ambienti estremi. Il sistema prototipo si basa sul modello teorico definito e proposto da Camuffo (2019) ed è composto da una termoresistenza e da un termoigrometro, che accoppia una termoresistenza e un sensore capacitivo ed è equipaggiato con un'unità di riscaldamento, che si attiva solo se l’umidità dell’aria è maggiore del valore massimo nell’intervallo di migliore operatività del sensore capacitivo. Lo strumento consente di derivare indirettamente l’umidità relativa effettiva dell’aria a partire dalla misura della temperatura dell’aria e dalla temperatura di rugiada dell’aria riscaldata, che è una variabile conservativa del contenuto di vapore dell’aria. La sperimentazione è stata condotta in ambiente controllato al fine di ottimizzare sia l’accensione dell’unità di riscaldamento in funzione dei tempi di risposta dei singoli sensori sia la frequenza minima di campionamento e superare le limitazioni della strumentazione attualmente impiegata negli ambienti ad elevata UR

    An unusual Barothermometer

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    An unusual instrument, named "Barothermometer", belonging to the collection of Villa Vigoni, on the Como Lake, Italy, is analysed. The instrument is composed of a U-shaped thermoscope and a spirit thermometer. Both instruments have their tubes placed side-by-side on the same frame and use the same scale. It measures the air temperature and the tendency of the barometric pressure to predict weather changes. A study is made to clarify the operating principle and produce the instructions for use. The development of the ideas to which the instrument has been inspired follows a tree starting with the Galileo's thermoscope, the Amontons air thermometer and finally the Adie sympiesometer. The measuring method is typical of the first half of the 19th century, but the construction details in aluminium, the fonts used in the printed instructions and the colour fading suggest that the instrument was built around 1930-40

    A Comprehensive study of the microclimate-induced conservation risks in hypogeal sites. The mithraeum of the Baths of Caracalla (Rome)

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    The peculiar microclimate inside cultural hypogeal sites needs to be carefully investigated. This study presents a methodology that aimed at providing a user-friendly assessment of the frequently occurring hazards in such sites. A Risk Index was specifically defined as the percentage of time for which the hygrothermal values lie in ranges that are considered to be hazardous for conservation. An environmental monitoring campaign that was conducted over the past ten years inside the Mithraeum of the Baths of Caracalla (Rome) allowed for us to study the deterioration before and after a maintenance intervention. The general microclimate assessment and the specific conservation risk assessment were both carried out. The former made it possible to investigate the influence of the outdoor weather conditions on the indoor climate and estimate condensation and evaporation responsible for salts crystallisation/dissolution and bio-colonisation. The latter took hygrothermal conditions that were close to wall surfaces to analyse the data distribution on diagrams with critical curves of deliquescence salts, mould germination, and growth. The intervention mitigated the risk of efflorescence thanks to reduced evaporation, while promoting the risk of bioproliferation due to increased condensation. The Risk Index provided a quantitative measure of the individual risks and their synergism towards a more comprehensive understanding of the microclimate-induced risks
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