Sunny Skies

November 6, 2016
By Damond Benningfield

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For most of the 17th century, the number of ship wrecks dropped. Credit: Artist- Willem van de Velde the Younger, public domain

For most of the 17th century, the Sun pretty much went to sleep. That appears to have been good news for the ships that plied the waters of the New World. The number of shipwrecks dropped — suggesting that the number and strength of tropical storms went down as well.

To help understand what our planet’s warming climate might mean for future hurricanes, researchers look to the past. Among other things, they study how storm intensity has changed during periods of a warmer or cooler climate.

An especially cool period took place from about 1645 to 1715. It’s known as the Maunder Minimum. It was a period when the Sun showed almost none of the dark magnetic storms known as sunspots. Fewer sunspots means that Earth was receiving less energy from the Sun, causing the climate to cool.

To see what that meant for tropical storms, a team of researchers looked at two things over a period of several centuries. First was tree rings in old slash pine trees in Florida. Tropical storms are bad for the trees, so the rings from those years are stunted. And second, they examined records of Spanish ships that wrecked in and around the Caribbean during hurricane season.

Those two items revealed a 75% drop in tropical storm activity during the Maunder Minimum. That suggests that Caribbean waters were cooler then, and the atmosphere less friendly for storm formation. It also suggests that the opposite could be true as the climate heats up — making the future more hazardous at sea and along the coasts.