Stefan Norrgård

• Doctor of Philosophy
• Researcher at Åbo Akademi University

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 ci...

On Tuesday 24 March 1903, the Aura River in Turku was declared ice-free, which was three weeks earlier than usual. Two local newspapers, Åbo Tidning and Åbo Underrättelser, labeled it as the earliest breakup in the memory of the oldest man. At that time, there were no official records of the breakups; however, the newspapers’ statements were not en...

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 pape...

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...

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...

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...

This paper presents the first interdecadal and interannual periodisation of the climate in West Africa between 1750 and 1800. The climatic synthesis is founded on previously unexploited British documents written at Cape Coast Castle, Cape Coast, Ghana and travel journals, which are combined with previous research on the Sahel. By combining historic...