Student Probability 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 312

Date: Tuesday, March 8, 2022, 9:50 a.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, some 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.