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Photo: High tide sunny day flooding in Miami, Florida. (Photo credit: B137, CC BY-SA 4.0, via Wikimedia Commons)

Many news outlets are reporting on a ‘new’ moon wobble that will result in an increase in coastal flooding in the coming decade. In reality, the lunar wobble is not new at all; it was first discovered in the early 1700’s. Today, scientists understand that the wobble appears on a regular schedule, and it is known to reoccur every 18.6 years. What is new is our planet’s unprecedented and rapid global climate change. This, combined with the regularly occurring moon wobble, will likely result in devastating coastal flooding around the world during the near future.

To gain an understanding of how the moon wobble will affect coastal flooding, we must recall how the moon influences our tides. The moon, in its regular orbit around the Earth, exerts a pull on our planet. This pull is gravitational in nature, and the pull is felt differently in various parts of the globe and on various objects- depending on the latitude and the nature of the object. The ocean, being a non-solid entity, is far more malleable and yielding than firm land. The seas stretch and contract under the push and pull of the gravitational forces exerted by the moon, and this produces our regular and predictable tidal process.

At times, the routine pull of the lunar gravitational force combines with other celestial influences, and a ‘spring tide’ occurs. The spring tide has nothing to do with the season of spring, but instead refers to the ‘springing forth’ of the tides. The spring tide occurs when the earth, the sun, and the moon are all in alignment- this causes a much greater than usual gravitational pull on the oceans. During this time, the regular high tides that occur twice each day will be even higher. If the spring tide is combined with other factors, the tides can become destructively high, especially during our current situation of rising sea level. Stir all these variables together, and we have a recipe for disaster when the moon wobble is added to the mix.

The next moon wobble cycle will occur in the coming decade, during the 2030’s. Scientists are warning that this natural phenomenon, combined with the other factors mentioned above, will almost certainly result in major damage to infrastructure, displacement of entire communities, and significant property damage and destruction. But how can a ‘moon wobble’ result in all these dire consequences? Let’s take a look at the moon wobble and how it will affect our tides.

During the first half of the moon wobble cycle, tides are suppressed, and are generally lower than normal. During this phase, the regular high tides will be lower than normal, and the low tides are higher than normal. However, in the second half of the moon wobble cycle, the reverse occurs: high tides are intensified, and the low tides become even lower. The difference between high tide and low tide becomes much greater. But most importantly, the high tides that will come during the second half of the moon wobble cycle will now coincide with those other factors that have already augmented high tide levels.

Rising sea levels, glacial ice melt, and changes in ocean and air currents will make this next moon wobble a dangerous brew. In recent years, the National Oceanographic and Atmospheric Association has recorded about 600 high tide floods annually. However, during the second half of the moon wobble cycle, they are predicting three to four times that many, during the 2030’s. If ever there was a good time to fortify flood protection measures, this relatively calm and quiet decade is it- the coming decade will be too late.

Image: Graphic visualization map of Gulf Stream seen through sea surface temperature created by NOAA NESDIS.

The mighty Gulf Stream is an invisible force that has a vast impact on the entire planet, but very few people even know what it is! Many might guess that the Gulf Stream is a wind system, but they would be wrong. The Gulf Stream is actually a powerful ocean current; one that has a significant effect on far-flung weather systems, the Atlantic hurricane season, and annual rainfall levels for scores of countries. The influence of the Gulf Stream is felt most acutely throughout the ‘Western Hemisphere’, but the domino effect caused by this massive ocean current can sometimes determine weather patterns on the other side of the planet.

The Gulf Stream, as its name suggests, originates in the Gulf of Mexico. It is a massive column of warm gulf-water that flows in a loose formation about 60 miles wide. After it exits out of the Gulf, it moves northwards up the coast of the eastern United States and into Canada. This is the reason why seawater on East Coast beaches will reach a balmy warm temperature that delights bathers. On these beaches, temperatures of 80+ degrees Fahrenheit are common, whereas the ocean water on the west coast of the US will rarely rise above 70 degrees.

After moving up the eastern coast of the US and Canada, the Gulf Stream then crosses the Atlantic and begins descending along the western coast of the UK and Europe. This influx of warm water is why some beaches of Ireland and England sport palm trees, although these countries are at the same latitude as Newfoundland and northern Canada. After brushing against the European land masses, the Gulf Stream continues south to the great continent of Africa, and it is after leaving this region that problems may develop.

As the Gulf Stream moves south across the western coasts of Europe, the relatively warm water of the ocean current pushes colder water before it. In a recent press release from the Potsdam Institute for Climate Impact Research (PIK), climate scientist Stefan Rahmstorf describes the Gulf Stream as a "giant conveyor belt" that moves warm surface water north while sending cold, deep water back down south. He notes that the Gulf Stream moves 20 million cubic meters of water per second- approximately 100 times the flow of the Amazon River. This cold water is pushed from the African coast into the very important waters that lie between Africa, South America, and the Caribbean region- this is the spawning ground for Atlantic hurricanes.

Recent studies have indicated that the speed at which the Gulf Stream moves is slowing down considerably. This is a topic of concern among meteorologists and climate scientists, as any changes to the Gulf Stream will have significant ramifications to weather systems. The decrease in speed is not yet fully understood, but if it were to become permanent it is possible that the great Gulf Stream could be altered in such a way that major climate repercussions would result.

This year, the National Oceanographic and Atmospheric Association (NOAA) is predicting yet another ‘above average’ hurricane season. Last year (2020) was so active that it broke all the records. There were so many named storms in that year that the entire list of pre-assigned storm names was used up, as well as the full list of Greek names that serves as a back-up supply. In 2020, there were 30 named storms, of which a record-breaking 12 made landfall on the US continent.

The World Meteorological Organization (WMO), which is the agency that names the storms, realizes that this is the way of the future. This organization has now prepared a second list of names to be used in the event that all 21 names on the regular list are used up. Greek names will no longer be used, and the second list of names will automatically kick in when the 22nd named storm is formed. This is an indication that more-frequent hurricanes are now considered probable. It’s not seen as likely that 2021 will equal the hyperactive hurricane season of 2020, but neither will it be a quiet year. The first named storm of 2021, Ana, arrived early in the season, which is thought to be an indicator of a heavy storm season. If the all-important Gulf Stream permanently alters its ancient habits in any significant way, the ripple effect is likely to have a major impact on the entire planet, and frequent hurricanes will be at the top of the list.

Photo: Rio Grande City, Texas, July 26, 2007 — FEMA Public Assistance Specialists Sheila Luster and and William Ciarelli inspect the Starr County Memorial Hospital with administrator Thalia Munoz to determine if the county will be eligible for federal assistance to offset expenses caused by the recent flooding. Bob McMillan/FEMA Photo

When a community suffers a flooding emergency, there are often injured people who need immediate medical assistance. But what happens if the nearest hospital is also affected by the flood? What if the hospital itself is flooded?

Hospitals present numerous challenges as far as flood protection. Because the patient areas must be kept clean and hygienic, it is very common for electrical equipment to be housed in basement areas, even though the loss of electrical power at a hospital can be deadly for patients who may rely on life-sustaining machines. Most hospitals have emergency back-up power systems, but these are not sufficient to weather lengthy outages. One facility in Houston was left without power for a full two weeks after a hurricane flooded its first and second floors, knocking out the electrical systems. Patients at this facility had to be evacuated, which can be a risky and complicated operation.

Once a medical facility floods, there are many epidemiological issues that would not be present in a non-medical building. For eaxample, after any large intrusion of water, there will be mold issues left behind. In the best case scenario, the water may have been relatively clean freshwater. But in most cases, the water is tainted with sewage or other pollutants. If dirty or polluted water seeps into walls and flooring, it often cannot be adequately cleaned to hospital standards. What ensues is a very costly and time-consuming process of removing the affected materials, cleaning and disinfecting the foundation, and installing new floors and walls. This operation cannot take place while patients are in residence, so there may be a need for patient evacuation during the repairs. The process is pain-staking, extremely expensive, and requires a lot of time.

Given the extreme measures to which a medical facility is subjected after a flooding event, it is no surprise to learn that these facilities go to great lengths to prevent flooding and to protect vital operations. Because hospitals play such a critical role in society, and their full capacity is required during disasters like flooding events, these facilities are given extra protection from floods while still in the blueprint stages. The most common form of protection for hospital buildings are flood barriers or gates that automatically deploy at the first sign of trouble. These flood barriers are best when built into the original design of the building, but can also be retrofitted to an existing building. As we have seen a remarkable geographical expansion in active flood plains across the country, there are many older hospitals that were once flood-safe, but are now at risk.

Fortunately, there are commercial companies that can install permanent or temporary flood protection devices that can reliably defend even huge medical compounds. Depending on the type of items or buildings that must be kept dry, there are several strategies, including:

• Permanent waterproof casings for outdoor HVAC units.
• Temporary flood panels that can be installed quickly by maintenance staff.
• “Puddle guards” that can be installed in doorways to block small amounts of water.
• Automatic flood panels that deploy instantly without need for human engagement.
• Flood doors that can be securely closed by staff when needed.

All of these types of flood protection devices and systems can be customized to fit any existing building, and they can also be fitted during the planning and construction of new buildings. Because society relies on functioning hospitals in particular during a disaster, it is of utmost importance that medical facilities be protected by the latest technology. We have seen great strides in flood protection during the past decade, and this expertise will increasingly be required as climate change brings ever more frequent natural disasters to our doorstep.