Wind Impact on Sea Level Variability along the US Atlantic and Gulf Coasts: Implications to Coastal Flooding Hazard

Summary | Methods | Results

Summary

Sea level variability is driven by a combination of processes, including gravitational forces, ocean currents, and winds. This study investigates the contributions of offshore and local wind direction and magnitude to non-tidal residual (NTR) corrected for global mean sea level rise and local vertical land movements along the US Atlantic and Gulf coasts, and their implications for coastal flooding. Daily mean sea level and local wind data from eighteen National Oceanic and Atmospheric Administration (NOAA) tide gauges were analysed alongside offshore wind data from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP-NCAR) reanalysis. Wind velocity fields were decomposed into 12 directional components (0° to 165°) relative to the coastline to evaluate the directional influence of wind on sea level variability. Annual correlation analyses were conducted to analyse the relationship between wind forcing and sea level variability at each station. Our results indicate that local winds have a negligible impact on sea level variability, regardless of their direction. In contrast, offshore winds account for 30–50% of the variability at ten stations, 15–30% at four stations, and less than 15% at the remaining four stations. Each station exhibited a dominant range of wind directions. Additionally, we identified a regional wind pattern that is temporally correlated with the occurrences of extreme high and low NTR events. These findings highlight the significant influence of offshore winds on coastal sea levels, emphasizing the need for coastal flood mitigation strategies to incorporate offshore wind patterns into risk assessments.


Study Area

Figure 1. (Location of US Atlantic and Gulf coasts showing the tide gauge stations used in this study. The colored coastlines mark the Middle Atlantic, South Atlantic (blue), and Gulf coast (magenta). The Key West station is not part of a distinct region because it is located on an island between the Gulf and Atlantic coasts.

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Methods

Figure 2. Schema of the workflow of this study elaborating the data and methods used.

Main Results
Figure 3. A year-long daily mean values of NTR (black), offshore wind (orange), and local wind (blue) time series for the dominant wind azimuth and their correlation analyses of three representative stations for the year 2011. a AP time series with wind magnitude calculated for azimuth of 75°. d VK time series with wind magnitude calculated for azimuth 15°. g FP time series with wind magnitude calculated for azimuth 45°. b, e, and h Scatter plots of NTR and remote wind magnitude for 2011 show a good correlation between the two observations for FP and AP (R2= 0.22–0.4) and no correlation for VK (R2 = 0.0). The regression lines are shown in red. c, f, and i Scatter plots of NTR and local wind magnitude for 2011 show no significant correlation between the two parameters.

Figure 4. Location map of tide gauges along the US Atlantic and Gulf coasts used in this study and the inferred dominant wind directions. Colored dots indicate the correlation values (R2) between NTR and wind strength components in the dominant direction.

Conclusion

Wind forcings play a significant role in understanding sea level variability along the U.S. Atlantic and Gulf coasts. Our study identified offshore winds as the primary driver of NTR variability, while local winds exhibited insignificant influence across all stations. We observed a seasonal sea-level pattern at ten of the eighteen stations, spanning three distinct periods: January to March, April to August, and September to December. Offshore winds accounted for 30–50% of variability at ten stations (SH, AC, SP, CS, FP, FB, NP, CW, AP, PC), 15–30% at other four stations (MT, DK, CK, and TP), and 0–15% at the last four stations (SW, BF, VK, and KW). Each station exhibited a range of dominant offshore wind directions that consistently influenced NTR variability. The dominant directions were primarily associated with winds that govern the extreme high and low NTR variability. Furthermore, a coherent regional offshore wind pattern was identified, temporally aligned with extreme high and low sea level events across multiple stations. These findings emphasize the critical need to incorporate offshore wind dynamics into predictive sea-level models. By understanding these patterns, researchers and planners can improve the accuracy of coastal flooding forecasts and develop targeted strategies to protect vulnerable coastal communities. As climate change and rising seas intensify the risks faced by coastal regions, integrating offshore wind data into flood mitigation efforts will be essential for building resilience against future hazards.

Published work:

Kataraihya, D., & Wdowinski, S. (2026). Wind impact on sea level variability along the US Atlantic and Gulf coasts: implications to coastal flooding hazard. Natural Hazards, 122(7), 294. https://doi.org/10.1007/s11069-026-08041-9



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