Atmosphere Ocean Science Friday Seminar

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Quantifying changes in probability distributions of sea level from tide gauge data

Speaker: Andrew Brettin, CAOS

Location: Warren Weaver Hall 1314

Date: Friday, February 18, 2022, 4 p.m.

Synopsis:

Understanding the risk that sea level change poses to coastal communities requires not only consideration of the slowly varying mean trends, but also how probability distributions of sea level are changing. In this presentation, I will show how daily distributions of sea level have changed since 1970 and identify locations where changes in distributions of sea level are significant. We apply quantile regression to daily observed sea level from 80 tide gauges around the world and project these quantiles onto Legendre basis functions, which digest the trends in quantiles into changes in the statistical moments that characterize the shape of the distribution. Although the dominant trend at most coastal locations is the change in the mean, several tide gauges exhibit changes in higher order moments, such as the variance, skewness, and kurtosis. These results draw attention to the assumption made by several studies which assume that changes in probability distributions of sea level will remain negligible under anthropogenic climate change.