A recent study led by members of NASA‘s Sea Level Change Science Team at the University of Hawaii shows high tides will exceed known flooding thresholds in the US more frequently. According to the study, every US coast would see rapidly growing high tide floods in the mid-2030s, when a lunar cycle will compound rising sea levels driven by climate change.
High-Tide Floods Are What They Sound Like
As coastal sea levels rise, high tide flooding – flooding that causes public inconveniences such as road closures — is becoming more regular. Coastal flooding is no longer caused by a big storm or hurricane as the relative sea level rises. Due to climate-related sea-level rise, land subsidence, and the loss of natural barriers, flooding now happens with high tides in numerous places.
High-tide floods, often known as nuisance floods or sunny day floods, are already a common occurrence in many communities along the Atlantic and Gulf coasts of the US. In 2019, the National Oceanic and Atmospheric Administration (NOAA) reported around 600 such floods.
Rising sea levels are predicted to become increasingly obvious and severe along most of the continental US shoreline in the next decades, according to NOAA, arguably more so than any other climate-change-related hazard.
Any acceleration in sea level rise expected this century will exacerbate high tide flooding impacts over time while also shortening the interval between flood episodes.
What Might Happen In The Mid-2030s
According to the first analysis that takes into account all known oceanic and astronomical factors for floods, starting in the mid-2030s, the alignment of increasing sea levels with a moon cycle will cause coastal communities all over the US to begin a decade of substantial rises in flood numbers.
According to the study, depending on the positions of the moon, earth, and sun, floods can occur in clusters lasting a month or longer. When the moon and earth align with each other and the sun in precise ways, the accompanying gravitational pull and the ocean’s response may cause city people to face floods every day or two.
“Low-lying areas near sea level are increasingly at risk and suffering due to the increased flooding, and it will only get worse,” NASA Administrator Bill Nelson was quoted as saying in the study.
“The combination of the Moon’s gravitational pull, rising sea levels, and climate change will continue to exacerbate coastal flooding on our coastlines and across the world. NASA’s Sea Level Change Team is providing crucial information so that we can plan, protect, and prevent damage to the environment and people’s livelihoods affected by flooding.”
Even though high tide floods include a little amount of water compared to hurricane storm surges, they should not be overlooked, as 10-15 floods every month would have an impact on enterprises and health.
Despite the fact that the moon is presently in the tide-amplifying phase of its cycle, sea levels have not increased to the point where high tides cause regular flooding along most US coastlines, even with this lunar help. When the cycle comes around to magnify tides again in the mid-2030s, there is concern that it will be a very different tale.
There is concern about a surge in flood numbers along almost all of the US’ mainland coastlines, as well as in Hawaii and Guam. Perhaps the far northern coastlines, including Alaska’s, will be spared for a decade or more.
Moon Wobble — What Is It?
The moon’s “wobble,” as NASA refers to it, is a cyclical shift in the moon’s orbit that might cause coastal flooding in the 2030s. It occurred for the first time in 1728 and occurs every 18.6 years. On our planet, this gradual fluctuation either suppresses or intensifies tides.
The earth’s typical daily tides are suppressed for half of the Moon’s 18.6-year cycle: Tides are enhanced in the other half of the cycle, when high tides are lower than average and low tides are higher than typical: The high tides are becoming higher, and the low tides are getting lower.
The global rise in sea level only pushes high tides in one direction: up. The study said that half of the 18.6-year lunar cycle reduces the influence of sea-level rise on high tides, while the other half enhances it.
What Is The Research’s Methodology?
The researchers came to this conclusion after looking at 89 tidal gauge locations in every coastal state and territory in the US except Alaska.
A NASA report said that the team developed a new statistical framework that mapped NOAA’s widely used sea-level rise scenarios and flooding thresholds, as well as the number of times those thresholds have been exceeded annually, astronomical cycles, and statistical representations of other processes known to affect tides, such as El Niño events. They forecasted results until 2080.