Solar Activity and Lunar Precessions Influence Extreme Sea‐Level Variability in the U.S. Atlantic and Gulf of Mexico Coasts

Abstract

Along the Atlantic coast of the United States, interannual sea-level variations of up to 20 mm are superimposed regionally upon the global average sea-level rise (~3 mm/year) from human-caused global warming. These variations affect the degree of coastal flooding and related damage during the highest annual tides. Interannual sea-level variations have been attributed to several atmospheric and oceanographic processes. In the present analysis, detrended tide gauge data isolate >5-year interannual variations. These variations can be reliably reconstructed (>77% of the variance explained) with Fourier coefficients that have frequencies related to lunar orbit (nodal and apsidal precessions) combined with solar activity. Although a causal relationship between astronomical forcing and extreme sea levels remains elusive, the reconstructions may provide an effective method for projections of extreme sea levels. Two reconstructions project that anomalously high sea levels may occur in the late 2020s, mid-2050s, early 2060s, early 2070s, and late 2090s.

North American East Coast Sea Level Exhibits High Power and Spatiotemporal Complexity on Decadal Timescales

“…With respect to the possibility that modulation is driven by interfering, periodic signals, superimposed variability at 11 and 13.8 year periods would "beat" at 55 year periods with an apparent frequency of 12.4 years, roughly consistent with Figure 2. The responsible processes underlying periodicity at these frequencies are not clear, although the former period is similar to the solar cycle (Valle-Levinson & Martin, 2020) and the latter has been identified in the Arctic Oscillation index (Jevrejeva et al, 2003). A key difficulty for assessment of this possibility is the inability to observe multiple modulation cycles at most locations and resolve closely spaced spectral peaks.…”

Subinertial Sea Surface Heights Anomalies Estimated Using High Frequency Radar Surface Current Data in the Mississippi Bight

“…However, their study was limited to coastal sea level measurements with no consideration of the sea level over the broader shelf. Valle‐Levinson and Martin (2020) used coastal sea level measurements to determine the solar and lunar contributions to sea level variability at interannual time scales along the coastal region of the nGOM.…”

A Demonstration of a Simple Methodology of Flood Prediction for a Coastal City Under Threat of Sea Level Rise: The Case of Norfolk, VA, USA

“…Of all these factors, only future tides are relatively predictable, though due to SLR and anthropogenic coastal changes there are also unpredictable changes in tidal range over the years that are different from place to place (Cheng et al., 2017; Lee et al., 2017). In addition, the 18.6‐year lunar nodal cycle can impact SLR and high tide water levels (Baart et al., 2011; Haigh et al., 2011), and some studies suggest that solar activity and lunar precessions can affect interannual variations in extreme sea level (Valle‐Levinson & Martin, 2020); all these effects are often not been considered in SLR projections, adding uncertainties.…”