Improving the Hurricane Climate Record

The link between hurricanes and climate change is one which science is still working to understand. Warmer ocean temperatures in the future would tend to provide more fuel for stronger individual storms, but does this necessarily mean more hurricanes as a whole? In order to answer this question, scientists need more data as the more reliable satellite-era hurricane records extend back only as far as the 1960s. While there were hurricane records kept before this, it is likely that quite a few storms went unrecorded, especially during the latter half of the 1800s when the U.S. coastline was much more sparsely populated. In order to extend the hurricane record back further in time, researchers at Rice University and the Massachusetts Institute of Technology are looking to tree rings, sediment layers in blue holes, as well as coastal ponds to help fill in the gaps.

Coastal ponds and blue holes provide evidence of long-ago hurricanes by preserving layers of sediment within them. When a hurricane washes sand inland and deposits it within these formations, scientists are able to see when a particular section of the coastline was hit by a hurricane. Data from tree rings, by themselves, are not very conclusive when it comes to indicating past hurricanes, but correlating times of heavy rainfall with disturbances in the sediment is key to unlocking the hurricane climatology recorded by tree rings.

However, coastal ponds, tree rings, and blue holes only provide very local snapshots of hurricane climatology, in that a hurricane has to pass fairly close to these locations to create a measurable disturbance in the record. In order to get a better idea of how hurricane frequency is changing on an ocean- wide scale, a network of sites needs to be examined. Researchers in this latest study have found that sites bordering the Gulf of Mexico and the Caribbean are better represented in the climate record, currently, but that more samples are needed along the coast of the southeast U.S., especially in the Carolinas.