The main drivers of basin-wide sea-level extremes in the Red Sea are wind variations over the southern part of the sea, according to research on the relative contributions of surface winds and atmospheric pressure on sea-level rises in the Red Sea. This evenly drives sea levels up and down based on the direction of the wind.
Modeling the driving forces of storm surges, such as wind speeds and atmospheric pressure, will help to manage developments along the Red Sea coastline. Image Credit: © 2022 KAUST; Morgan Bennett Smith.
Alterations in sea levels frequently occur responding to meteorological forces like atmospheric and wind pressure. Such meteorological surges, or so-called storm surges, can result in coastal flooding and erosion and are taken into account as one of the biggest threats to coastal environments and communities.
Thus, comprehending storm surges and their driving forces seems to be a crucial factor for coastal planning and management activities.
Various studies performed on storm surges have been carried out in a few oceans and seas throughout the world, for instance, in the coastal areas of the Bay of Bengal and along the coast of the North Sea. However, few have been performed on the Red Sea.
This made Ibrahim Hoteit, Sabique Langodan and collaborators from King Abdullah University of Science & Technology’s (KAUST) Red Sea Modeling and Prediction Group want to discover more about the meteorological origin of sea-level extremes in the Red Sea basin.
Understanding sea-level extremes requires high temporal (hourly or less) data from tidal gauges distributed along the coastline and over long periods, ideally decades. Unfortunately, long-term tidal observations are very scarce for the Red Sea.
Sabique Langodan, King Abdullah University of Science and Technology
To overcome this, the scientists used advanced computer simulations of storm surges to produce high-spatial-resolution (nearly 500 m) long-term datasets of sea-level alterations in the Red Sea.
They initially confirmed the datasets with hourly sea-level remarks for three years (2013–2015) from six tidal gauges together with the Saudi coast of the Red Sea.
Furthermore, they utilized the ADvanced CIRCulation (ADCIRC) storm surge model, which resolves the vertically combined shallow-water equations for water-surface elevations and currents to hindcast sea-level increase from meteorological forces in the Red Sea for more than 37 years, spanning from 1980 to 2016.
This approach allowed the contribution from surface winds and atmospheric pressures to be modeled separately and provided spatial maps of the maximum sea-levels resulting from the pressure-only, wind-only and combined wind-pressure forcing simulations.
Sabique Langodan, King Abdullah University of Science and Technology
Hoteit states that the work has significant impacts on regulating and developing the Red Sea coastline. This includes the suggested megacity projects and the quick expansion of tourism along the coast. Also, it will aid plans to alleviate their impact on the special marine surrounding and coral reefs of the Red Sea.
We are now investigating the predicted changes in these extremes due to the projected climate change impacts, in terms of intensity and frequency.
Sabique Langodan, King Abdullah University of Science and Technology
Journal Reference:
Antony, C., et al. (2022) Sea-level extremes of meteorological origin in the Red Sea. Weather and Climate Extremes. doi.org/10.1016/j.wace.2022.100409.