Jenifer Barnes

Climate Links and Variability of Extreme Sea-Level Events at Key West, Pensacola, and Mayport, Florida

Analysis of long-term coastal tide records at Key West, Pensacola, and Mayport, Fla. examines the variability of extreme high-water events. Linear trends of event water level at Key West and Pensacola support findings elsewhere that increases in extreme water level are consistent with increases in global mean sea level. A link between event variables and the Atlantic multidecadal oscillation (AMO) is found at the Key West and Pensacola stations. Mayport does not exhibit such a link, likely the data are confounded by estuarine flows and oceanographic interactions with the St. Johns River. Quantile regressions and extreme value distributions suggest dynamic trends in the event variables at Key West and Pensacola as a function of AMO, indicating an increased variability in relation to linear models that should be of interest to coastal planners and forecasters.

Probabilistic Projection of Mean Sea Level and Coastal Extremes

AbstractFundamental uncertainties governing sea level rise projections are associated with the rate of acceleration in global sea level rise and the local factors affecting relative sea level. Recent models and observations of global ice sheets and their contributions to sea level, as well as climate models, suggest that significant sea level acceleration is imminent, yet observational data from tide gauges and satellites have not yet found rates consistent with some of the projections. To allow coastal planners a way to incorporate the uncertainties of acceleration, a synthesis of observed sea level data with selected distributions of acceleration and the current rate of rise is proposed to provide probabilistic estimates of future sea levels. The resulting distributions can be adopted in a risk-based framework to assess project vulnerability. As geophysical understanding of the climate-forced sea level dynamics improves, the selection and veracity of these distributions and their sea level projections w...