Tree rings and Spanish shipwrecks shed light on tropical storm activity

Washington Post : To study the frequency of hurricanes in the Caribbean Sea before US record keeping began in 1851, researchers looked at some 657 Spanish shipwrecks that occurred between 1495 and 1825. Because hurricane winds and storm surges not only sink ships but also stunt tree growth, the researchers compared their findings with tree-ring data. The scientists found that fewer ships than expected sank during the period 1645–1715, which indicates a relative lack of tropical storms. The lull in hurricane activity coincides with a period of planetary-wide cooling known as the Little Ice Age and a period of low sunspot activity called the Maunder Minimum. “We know that there’s a very strong link between sea surface temperatures and tropical cyclone activity,” says Valerie Trouet of the University of Arizona, one of the researchers involved in the study. Better understanding of the complex interactions between global temperatures and storm activity will become increasingly important for assessing the potential impacts of future climate change.