Variations in the sun’s output may explain some of the natural changes in Europe’s climate during the past 1,000 years, including the deadly, cold winters of the 16th and 18th centuries. Earth scientists recently discovered that as solar output dipped, so did temperatures in the North Atlantic, which then may have cooled the climate in Europe.
When the sun produces less energy, known as a solar minimum, a high-pressure system may form in the atmosphere over the North Atlantic, according to the study published in Nature Geoscience. That high-pressure system blocks warm winds flowing from west to east, known as the westerlies, and allows cold northern air to flow over Europe.
“Indeed we propose that this combined ocean-atmospheric response to solar output minima may help explain the notoriously severe winters experienced across Europe between the 16th and 18th centuries, so vividly depicted in many paintings, including those of the famous London Frost Fairs on the River Thames, but also leading to extensive crop failures and famine as corroborated in the record of wheat prices during these periods,” said lead author Paola Moffa-Sanchez of Cardiff University in a press release.
This analysis of the interplay between sun, sea and climate used a combination of fossils, sun-spot records and computer simulations. The chemicals held within fossils of marine microorganism provided information about the temperature and salinity of the ocean over the past millennia.
Sun-spot records gave clues to solar activity, since low numbers of spots means low solar output. The data from fossils and sun spots was then used to create a computer model of how solar changes influence Europe’s climate.
The results of this study of historical patterns backs up other research on recent interactions between solar output and climate. Although climate change deniers have tried to use solar output variation to explain global warming, the authors of the Nature Geoscience paper noted that human influences on the climate are now more significant than those of the sun’s alterations in output.
Photo: Thames Frost Fair 1883-1884. Thomas Wyke, Wikimedia Commons