Toward a Methodology for Estimating Coastal Extreme Sea Levels From Satellite Altimetry

Abstract

This work represents the first attempt to study the behavior of sea level extreme events nearshore using satellite altimetry data. A novel approach based on the application of a nonstationary extreme model to nontidal residual monthly maxima from remote data is presented. With the aim of countering the lack of accuracy, an extreme scale factor to correct satellite data is defined. The extreme scale factor depends on local morphology and its definition makes use of the information provided by 14 tide gauges along the North American East Coast. The methodology is validated using eight additional tide gauge records along the study region. Low differences on values associated to high return periods using satellite and tide gauge data input are found for all the validated locations. Besides, a regional study of the climate variability of extreme sea levels from satellite is also presented. The found climate patterns strongly agree with the historical climate variations from in situ data. Results show a great potential of this approach, especially at those locations where in situ information is not available.