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At high latitudes, long-term changes in riverine ice break-ups are exemplary measures of climatic change and variation. This study compares cryophenological trends, patterns and changes for the rivers Aura (1749–2020), Torne (1693–2020) and Kokemäki (1793–2020); all sites are located in Finland. The Kokemäki River series is a new series from the city of Pori. The findings show statistically significant cross-correlations between the Aura and Kokemäki rivers but weaker cross-correlations with the Torne River. We attribute the latter to climatic differences caused by the higher latitude of the Torne River. Taken together, the many results of this study suggest that the spring climate in the south has changed more rapidly and become less predictable than in the north. Climatic extremes – warmer and wetter winters – in the 2000s resulted in the first recorded no-freeze events on the Aura and Kokemäki rivers. This was the culmination of a rapid increase in early ice break-up events and interannual variability over the last 30 years. The number of early events has increased in all three rivers since the early or mid-1900s, but the earliest recorded break-up day on the Torne River has changed only marginally in the last 100 years. Our dynamic temperature analysis shows that the ice break-up on the Torne River requires higher temperatures than in the south, and future changes in the timing of the break-up depend on April temperatures. In the south, on the other hand, future changes concerns the return period of no-freeze events, which depend on temperature and precipitation during winter. [ABSTRACT FROM AUTHOR]

Cross-dating is considered one of the most important principles of dendrochronology. The first known cross-dating attempts, conducted between the years 1737 and 1783 by independent researchers in France, Germany, and Sweden, were related to the identification of growth rings believed to have formed during the harsh winter of 1708–1709. In this paper, we present a novel perspective on the birth of dendrochronology and cross-dating in the 1700s. We focus on the ideas and experimental studies of one of the lesser known pioneers, Johan Leche (1704–1764), the Professor of Medicine at the Royal Academy (Turku, Finland). Instead of winter harshness, Leche was fascinated by the drought that killed and damaged several trees and tree species in the summer of 1757. Leche conducted several dendrochronological and field experiments described only in his unpublished manuscript filed in the National Archives in Sweden. Reviewing Leche's measurements of ring-width series of multiple radii and his comparisons between the radii, it seems only fair to include him in the long list of natural historians who made important contributions to the field of dendrochronology. His manuscript was never published, which is why Leche's dendrochronological experiments and recommendations never reached a wider audience. [ABSTRACT FROM AUTHOR]

The environmental history of the Caribbean has been strongly associated with the consequences of sugar cane agriculture and extreme weather phenomena. Consequently, other aspects of environmental change at play in the Caribbean region have remained less known. However, islands such as Anguilla, Barbuda, and Saint Barthélemy had no or very few sugar plantations. The fact that nonsugar producing islands had to find other ways of supporting themselves shaped their environmental history in ways that differed from that of the sugar islands. These alternative environmental histories deserve to be highlighted when presenting the historiography of the Caribbean. In this article, the island of Saint Barthélemy serves as a case study of an island where sugar cane agriculture was absent and tropical storms and hurricanes were of lesser consequence. In outlining the environmental history of Saint Barthélemy during the first decades of Swedish colonial rule, in the late eighteenth and early nineteenth century, the article shows that the Swedish takeover resulted in environmental changes. Sweden's ambitions and expectations concerning the improvement of the island were initially high and much effort was put into the development of the economy. The rationale for the Swedish plans was to exploit the few and scarce resources of the island, but it was the harbour that became the most successful endeavour. [ABSTRACT FROM AUTHOR]

Ice breakup (IBU) observations have been recorded for Aura River in Turku, southwest Finland, since the mid-18th century. The latest long-term investigation covered the period 1749–1906, but the series contains several biases. In this article, we present a fully revised and extended IBU series (1749–2018) of Aura River for climate research purposes. Instead of typical univariate IBU data (a single time series with one data point per year), this series includes three different types of IBU data. These are the initial observations of the ice starting to break up (IBU1), the river recorded as free from ice within city limits (IBU2) and, finally, the arrival of the ice from behind the Halinen dam, the so-called Halinen ice (IBU3). The IBU1 series shows negative, statistically significant long-term trends since 1749. While the other two phenological events also exhibit negative long-term trends, indicative of earlier and warmer springs towards the present day, their trends are not significant over multi-centurial scales. The IBU2 series is the only series covering the entire period, and it shows a significant negative trend towards earlier breakups (16 days) between 1919 and 2018. Consequently, breakups in March, which were extremely rare before the 1900s, have become common, while breakups in May (previously once per decade) have not occurred since 1881. These results are indicative of sub-seasonal trends in the breakups. Our results also confirm defects in the previous time series, which shows a bias of up to 16 days. [ABSTRACT FROM AUTHOR]

ABSTRACT This investigation encompasses the first presentation of the log-board, which was the primary source used to compile logbooks on board Royal Navy vessels in the 18th century. All wind force and weather descriptions during the day were entered on the log-board before they were transcribed to the logbook, which is why the logbook should be approached as a secondary source. This study shows that although Royal Navy logbooks represent valuable compilations of what was written on the log-board, it cannot be ascertained exactly how the logbooks were compiled. Seven logbooks from the Cumberland for August 1782 were evaluated by comparing them to the log-board from the same vessel, and the purpose was to determine the validity of logbook wind and weather entries. The results show that wind direction was most consistently transcribed according to the log-board and, furthermore, that a majority of the wind force entries derived from the 1 p.m. entry on the log-board. The kappa statistic shows that both wind force and weather conditions were most consistently copied from the 1 p.m. entry on the log-board. The study concludes that the first wind force and weather entries in the logbooks were not made at noon when the vessel was positioned. While the positioning of the vessel was made at the end of the nautical day, the first wind force and weather entries most likely describe the conditions 23 h earlier. [ABSTRACT FROM AUTHOR]