Past, Present, and Future Threat of Tropical Cyclones and Coastal Flooding in New York City
Wednesday, 16 December 2015: 08:30
309 (Moscone South)
In a changing climate, future inundation of the United States’ Atlantic coast will depend on both storm surges associated with tropical cyclones and the rising relative sea-levels on which those surges occur. We seek to analyze the risk of future coastal inundation for New York City in the context of a long-term historical analysis of storm surge events and sea level rise. In order to overcome the limitation of a short and incomplete observational record of tropical cyclones in the north Atlantic, we use proxy sea-level records, and downscale three CMIP5 models to generate large synthetic tropical cyclone data sets for the north Atlantic basin; driving climate conditions span from AD 850 to AD 2005. Combining results from a storm surge model with relative sea-level data, we find that mean flood heights for the region have increased by ~1.24 m from ~AD 850 to the present, a result that is significant at the 99% confidence level. In addition, changes in tropical cyclone characteristics have led to increases in the extremes of the types of storms that create the largest storm surge events for the New York City region. These results indicate that storm surge risk for the New York City region has increased considerably over the past millennium; as sea-levels continue to rise and storms possibly become more active, the risk of coastal inundation for the region is also likely to increase significantly in coming centuries. Thus, we combine future sea level rise projections with modeled storm surge heights for synthetic tropical cyclones downscaled from CMIP5 models. Results from this work will allow us to investigate the potential for future coastal inundation in the New York City region in the context of our historical analysis.