If you see the water in Biscayne Bay or local canals rising through November 9, and again on Dec. 4-5, don’t be too alarmed. Just be aware.
It’s part of the annual rite of passage called King Tides, the highest predicted high tides of the year that can lead to localized flooding, especially in connection with high winds or a concurrent rainstorm.
Earlier this year, Miami-Dade County released a quick synopsis of King Tides and how to prepare and take precautions as the year’s peak tides occurred earlier in October.
Islander News recently had a conversation with Dr. Joellen Russell, a renowned oceanographer, climate scientist and Distinguished Professor at the University of Arizona, to discuss what King Tides are and are not, and if they pose dangers in the future.
She explained that King Tides occur due to the combined amplified gravitational pull of the sun and moon at their closest points to Earth during full or new moons, known as a “perigean” spring tide.
Q. Dr. Russell, how familiar are you with King Tides?
A. Very familiar. Being in Arizona, it’s refreshing to talk about something like King Tides for a change.
Q. Why do these King Tides happen in the latter quadrant of the calendar year?
A. The biggest amplitude tides happen when the moon is huge (like earlier this month). It happens when we have a combination, and sun and moon forces make it one of the (higher) tides. You can compare it with the NOAA tides (chart). And it is possible to have these predicted well ahead of time.
Q. How does sea level rise impact King Tides?
A. As sea level keeps coming up, about 3 to 5 millimeters every year, it does get more significant. Working in Arizona, even, we use robot floats (with satellite images) in the Atlantic and off the Gulf Coast, and as the sea level rises, we see them bobbing up and down. We also check nitrates (levels to protect) the fish, and temperatures, and can see impacts.
Q. Can King Tides be controlled?
A. No … other than a seawall maybe. King Tides are a normal thing that always has happened with the sun and moon. Now, with 93% of the heat being absorbed by the ocean … as it absorbs, it’s one of the main drivers of warming the ocean. As molecules expand, the more space it takes up. Factor in the melting of (the ice in) Greenland.
So, add a King Tide to a rising sea level over time, year after year, and it’s like giving (NBA star) LeBron James a trampoline, something he doesn’t need, and that makes it more impactful.
Q. Is there any relation to the impact King Tides have with overbuilding?
A. It just means a risk, but we ignore it. But, in this case, we know (what’s coming). It could be more asphalt, sure, and the (engineers or builders) didn’t take into account how much water needs to be removed, but civil engineers today are really good, they’re building higher roads, and adapting to future conditions.
Q. I’ve heard that King Tides are not confined to Florida’s coast. Is that true? What about California?
A. Yes, it happens in the Carolinas and, especially, Virginia, even when it’s not really a King Tide. More of a nuisance flooding that takes place there. But, it even happens in Spain, just depends on the current.
In California, there are signs of increased erosion, but it’s not tidally associated with King Tides, just bigger wave heights, plus it’s been getting windier in the North Pacific the last three decades, and you’ll see pictures where people’s pools end up on the beach.
Q. Should we fear all of this?
A. King Tides are super predictable, even as to the exact time of day. With all we know about celestial mechanics, these are predicted years and years out. Keep in mind, the tides can change with winds and ocean currents.
It doesn’t look life-threatening. Just make sure the storm drains are clear and try not to wade in that water. My oldest friend’s wife, in Miami, suffered third-degree burns … we don’t know what was in that water.
Q. What’s the best advice for those on the coasts, such as in Key Biscayne?
A. Prep ahead of time. You want to make sure to move your vehicles to higher ground, maybe that means a high parking garage, and not be exposed to saltwater. You don’t want to drive or walk through that water, either, because you don’t know that, say, your neighbor’s septic tank is not leaking (and that mixes in).
King Tides only last four hours at their peak, so make sure you wash your car or feet if you are exposed.
Review your insurance. Make sure you have cleaning supplies.
As far as the city goes, clearing gutters, storm grates, making sure there is proper drainage. Install longer-term barriers. This is going to happen every year.
(Note: You can follow Dr. Russell on X at @deepblueseanext.)