8th World Climate Change Congress

Biography

Biography: Joanne Muller

Abstract

Forecasting future coastal storm impacts requires sophisticated modeling, predicated on accurate initialization data. The official NOAA database of historical hurricane tracks (HURDAT) along and near the Florida coast extends back in time to only 1851. However, this data is used for purposes along a spectrum from statistically estimating annual expected return frequencies to modeling the impacts of global climate change and sea level rise on shoreline change; hence, a longer and more complete dataset would result in greater accuracy at initialization. Current return period estimations used to generate insurance rates along the Florida coast appear to be an artifact of temporally-limited base data. In addition, research suggests 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. This interpretation has again, been challenged on the basis that the observational hurricane record is too short (161 years) and unreliable to reveal long-term trends in hurricane activity. Paleotempestology, a research area that uses geological proxy techniques to reconstruct hurricane frequency and strength over millennia, can address these limitations. We use the geologic record (Paleotempestology) to extend the HURDAT database even further back in time. This study presents continuous hurricane records for the Florida region that extend back well beyond the historic observational record (more than one thousand years). Hurricane overwash layers show clear active, versus inactive periods, of hurricane activity over the past few millennia. Correlations with sea surface temperature (SST) studies indicate a strong connection between SSTs and past Florida hurricane activity. In addition, the research demonstrates that the Gulf of Mexico and East Coast of Florida are sometimes in phase, but sometimes they are not. In addition to SSTs, climate drivers such as the Atlantic Meridional Mode (AMM), El Niño-Southern Oscillation (ENSO), and the position of the Intertropical Convergence Zone (ITCZ) may also exert significant influence over hurricane dynamics over longer time scales. These data sets will allow for increased accuracy in the determination of the spatial and temporal variation in hurricane impacts, thereby providing important information to reinsurance industries and emergeny planners.