RECENT ADVANCES IN THE EMERGING FIELD OF PALEOTEMPESTOLOGY

Hurricanes are the single most costly and destructive weather disasters in the United States. The 2017 hurricane season was the costliest to date with 17 named storms, 10 hurricanes and 6 major hurricanes. Damages are estimated at $306.2 billion, largely due to three storms – Hurricanes Harvey, Irma, and Maria. To understand the future damages that hurricanes could impose on an ever-growing coastal population, it is critically important to better understand the relationship between hurricanes and climate. Research suggests that a rise in sea surface temperatures, caused by anthropogenic climate change, has led to an increase in the intensity of hurricanes over the last 40 years. In addition, large-scale features of the climate system have been shown to affect hurricane activity, for example, the El Niño Southern Oscillation (ENSO) has been shown to influence hurricane frequency on yearly and decadal timescales. These relationships are difficult to assess however due to the brevity of the historical hurricane record (~160 years), making it is impossible to assess whether long-term trends in the climate system (centennial to millennial timescales) affect long-term hurricane dynamics. These questions can be addressed by means of paleotempestology, a relatively new field that utilizes geological proxy techniques to extend the hurricane record back several thousands of years. Over the past two decades, the number of paleotempestology records has increased substantially for Atlantic Basin sites along the Northwest Atlantic Ocean, Gulf of Mexico and Caribbean Sea. The most obvious characteristic of these records is that they reveal extended alternating periods of either greater or lesser hurricane activity over centennial and millennial timescales. In these studies, researchers have shown that large-scale climatic features such as ENSO, sea surface temperatures (SSTs), the latitudinal position of the intertropical convergence zone (ITCZ), and the North Atlantic Oscillation (NAO) are likely driving the alternating long-term behavior of hurricanes.