NASA is partnering with the U.S. Geological Survey (USGS) to better predict coastal flooding in Southern California. The U.S. space agency is reportedly using satellite and airborne mission imagery to help analyze the future impacts of “king tides” along the SoCal coastline. The joint effort aims to give emergency planners a more accurate picture of the risks that these unusually high tides present to coastal communities.
What is a King Tide?
According to the National Oceanic and Atmospheric Administration (NOAA), a king tide is “a non-scientific term people often use to describe exceptionally high tides.” Tides frequently swell in size when the moon and the sun align. As a result, their gravitational pull on the Earth is at its highest, thus producing higher tides.
King tides can be just a few inches higher than normal tides. However, when other factors such as coastal storms enter the equation, they can have damaging effects on the surrounding area.
For instance, officials in Fort Lauderdale, Florida, always prepare for annual king tides. Most coastal towns do. However, if Hurricane Dorian would hit land at the same time that a king tide occurs, the problem becomes much, much worse.
“Our biggest concern is the timing of any potential landfall of the hurricane during a king tide. If it happens at exactly the same time as the king tide that will make the storm surge impacts much greater,” Dr. Nancy Gassman, assistant public works director for the City of Fort Lauderdale, said in a CBS News 4 Miami report.
Even without an accompanying hurricane, king tides threaten coastal towns with high water levels that cause flooding. So, finding a way to stay ahead of these damage-inflicting, dangerous events is vital.
Fighting Rising Sea Levels
The ongoing effects of climate change are prompting sea levels to rise. Increasing ocean temperatures and melting glaciers are just two factors that heighten the seas and impact the tidal system. The Environmental Protection Agency reports that “sea level rise will make today’s king tides become the future’s everyday tides.”
Andrea O’Neill, an oceanographer with USGS, addresses the issue in a statement. “With rising sea levels, the extreme water levels experienced today with king tides will become more frequent and will become a challenge for our coastal communities and infrastructure.”
Unfortunately, higher waters seem inevitable in the future. To mitigate adverse impacts, coastal engineers must plan as far ahead as possible.
Researchers use The Coastal Storm Modeling System (CoSMos) to predict storm-induced coastal flooding, erosion, and cliff retreats. The online tool models flooding potential due to rising sea levels and coastal storms.
The California Coastal Commission also uses CoSMos to screen and analyze geographic areas to determine safe development sites. The system draws sea level data from tidal gauges that are scattered across the expansive California coastline. However, gaps between these devices prevent researchers from getting a complete and accurate picture of tidal impacts.
“These observations offer great insight at one particular location, but don’t show how flood levels may vary across our complex shoreline,” O’Neill said.
Painting a Bigger Picture
To paint a bigger picture, NASA is providing CoSMos developers at the USGS with data from satellites and airborne missions.
Specifically, members of NASA’s Earth Science DEVELOP team capture radar and optical imagery to more accurately predict the impacts of king tides. For example, optical imaging gathered from the Landsat mission enabled the team to update the baseline for impacts of future king tides along the Southern California coast.
The group also used radar imagery from a NASA airborne mission involving a modified Gulfstream airplane. The craft’s Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) system mapped “water excursion limits and coastal flooding from Santa Barbara to San Diego during a 2016 king tide.” Having valuable observational data like this will help researchers give better flood hazard forecasts to affected communities.
O’Neill noted that the USGS will also use the data to update and validate CoSMos flood simulations. She added, “This project provides a uniquely invaluable dataset for any end-users of CoSMoS, as well as other coastal researchers.”
Flooding in coastal towns across the country is likely to increase as the sea level rises. So, the USGS aims to ultimately expand the program beyond Southern California shorelines. The organization plans to bring the Northern California coast online “in the near future.”
As with any early warning system in an impending natural disaster, making faster predictions of where and when floods will hit, and forecasting what their impacts might be will help communities implement safety measures that save lives.