Spatiotemporal changes in extreme sea levels along the coasts of the North Atlantic and the Gulf of Mexico

Abstract

Extreme sea levels along the densely monitored coasts of the North Atlantic Ocean and the Gulf of Mexico have been investigated using high‐frequency tide gauge measurements in the GESLA‐2 data set (http://www.gesla.org). Our results, based on nontidal residuals and skew surges in records since 1960, confirm that mean sea level (MSL) is a major, but not a unique, driver of extremes. Regionally coherent linear trends and correlations with large‐scale climate patterns are found in extreme events, even after the removal of MSL. A similar conclusion, that MSL is a major but not the only driver of extremes, comes from a small number of long records starting in the mid‐19th century. The records show slight increases in the intensity of extreme episodes at centennial time scales, together with multidecadal variability unrelated to MSL. Objective statistical criteria have been used to investigate whether extreme sea level distributions are stationary or not, resulting in nonstationarity being favored in many records, with or without accounting for changes in MSL. Extremes have been found to favor a non‐Gumbel behavior at many locations, with implications for the accuracy of return levels for coastal engineering.

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

“…The introduction of seasonality in the extreme model allows to reproduce the behavior of NTR extreme values within the year. The evidence of the nonstationarity in sea level extreme events have been proved in previous studies at global (Menéndez & Woodworth, ), regional (Marcos & Woodworth, ), and local scales (Méndez et al, ; Menendez et al, ).…”

“…The results obtained along the coast using in situ measurements (Wahl & Chambers, 2015) agree with the previous ones, showing mainly a positive correlation along South and North Carolina coastline and the Gulf of Mexico. Several studies (Marcos & Woodworth, 2017;Menéndez & Woodworth, 2010) have already shown a correlation between La Niña phase and the occurrence of extreme events in the southern East Coast, mainly hit by the impact of TC's (see section 5.1).…”

“…In fact, previous studies based on TG records using the skew surge parameter (Marcos & Woodworth, 2017) or composite sea level (Wahl & Chambers, 2015) have already demonstrated that extreme sea levels in this part of the world are dominated by North Atlantic Oscillation and AO climate patterns, showing a strong correlation with their negative phase.…”

New York City Panel on Climate Change 2019 Report Chapter 4: Coastal Flooding

“…Studies of historical data have not found significant evidence in this region for larger storm tides due to the effect of climate change on storms (e.g., Marcos and Woodworth, 2017;Wahl and Chambers, 2016). Moreover, no quantitative evidence has been presented demonstrating that Hurricane Sandy was intensified or its storm tide was increased or made more likely by climate change (Lackmann, 2015;Mattingly et al, 2015).…”

Dominance of the mean sea level in the high-percentile sea levels time evolution with respect to large-scale climate variability: a Bayesian statistical approach

“…To investigate such large-scale climate variability, climate indices (denoted CI) like North Atlantic Oscillation (NAO) or Atlantic Multidecadal Oscillation (AMO) have been used; see e.g. Menéndez and Woodworth (2010), Woodworth et al (2011), Talke et al (2014), Marcos et al (2015), Wahl andChambers (2015, 2016), Mawdsley and Haigh (2016), Marcos and Woodworth (2017), Wong et al (2018). Far from being theoretical, these research studies bring societal benefits.…”