Moon wobble to bring surge in coastal flooding in 2030s, NASA study predicts

https://edition.cnn.com/2021/07/13/us/moon-wobble-coastal-flooding-scn-trnd/index.html

by jeffwass • 5 years ago

126 34 5 years ago

edition.cnn.com

If I understand correctly it's mainly the effect of the moon's nodal precession [0] in combination with climate-change induced rising sea levels.

I am curious about its effects on non-US coastal cities as well (also personally, as I happen to live in one). Hopefully it will be repeated/extended in the future.

[0] https://en.m.wikipedia.org/wiki/Lunar_precession#Nodal_prece...

zohch3• 5 years ago

If I understand correctly it's mainly the effect of the moon's nodal precession [0] in combination with climate-change induced rising sea levels.

Sea level rise since 1995 has averaged 3.4 mm per year[1].

Is there an expectation that this will accelerate significantly? or is a change in 30mm expected to contribute significantly to flooding?

[1] https://climate.nasa.gov/vital-signs/sea-level/

klyrs4• 5 years ago

As the average temperature increases, it seems reasonable to expect the rate of melting, thus sea level rise, increase. Add to that highly nonlinear effects like the "clathrate gun", and a continuing linear increase in sea level seems highly non-obvious

dillondoyle• 5 years ago

It seems like a lot?

Just first google result 2* C warming would be ~10cm and reading the effects of that sounds pretty bad.

https://www.vox.com/energy-and-environment/2018/1/19/1690840...

azinman2• 5 years ago

So what will coastal cities (eg Bay Area) do?

bufferoverflow• 5 years ago

Does Bay Area have that problem even theoretically? They are quite high up. It's the flat near sea level areas like Florida that are in danger.

foota• 5 years ago

Aren't places like the pier area pretty low?

mistrial9• 5 years ago

https://www.adaptingtorisingtides.org/

b112• 5 years ago

The Dutch might have a new industry, exporting their skill at reclaiming land from the sea.

And how to keep inland areas below sea level, pumped dry reliably.

rayrrr• 5 years ago

Sadly the Dutch have their own problems now and probably need to focus all of their efforts on their own coastline like the rest of us, unless you think they can export "an integrated approach, in which all stakeholders are involved in finding solutions for climate change issues" to other countries like the U.S. that are "more individualistic." https://www.pbs.org/wnet/peril-and-promise/2019/07/dutch-bar...

LeifCarrotson• 5 years ago

That's rather the opposite of this XKCD What-If on draining the oceans:

https://what-if.xkcd.com/53/

And after 2000 years of trying to hold back the sea, the Netherlands are finally high and dry. No longer living with the constant threat of a cataclysmic flood, they're free to turn their energies toward outward expansion. They immediately spread out and claim the newly-exposed land.

da_big_ghey• 5 years ago

Low Countries have this problem since centuries back, yes? Dikes, pumping, other options have mitigated issues. It is the developing country needing to worry, those with out money for these.

dogorman• 5 years ago

That CNN article is a crappy rewrite of this NASA press release: https://sealevel.nasa.gov/news/222/study-projects-a-surge-in...

koheripbal• 5 years ago

Which itself does not have any specific data on how much peak high tides will rise.

At least it gives the period of the lunar cycle -18.6 years, and we're at the peak right now.

londons_explore• 5 years ago

The article misses out a very important detail...

What is the scale of this effect? If I normally have a 7 meter tidal range, will I be getting a 9 meter range? Or just a 7.01 meter range?

saboot2• 5 years ago

https://scholar.google.com/citations?view_op=view_citation&h...

This appears to be the article being discussed. Figure two and reference 30 give numbers for the magnitude of the 18 year variation due to moon wobble. In St Petersburg, Florida, it's a 4.7 cm variation. Other parts of the world can experience up to a 30 cm variation of high tide variation.

So basically it's definitely something to account for with the linear rise of sea level due to climate change, with some years being worse relatively to others.

beowulfey• 5 years ago

Thank you for posting the original paper. Figure 2 has a great depiction of the effect. That 4.7 cm variation, because it cycles every 18 years, can increase or decrease the effects of inherent sea level rise: at a minimum of the cycle, an expected sea level increase of 8.9 cm instead ends up only being 4.1 cm; but by the next decade, an expected increase of 9.4 cm surges to a peak high tide of 14.1 cm higher than before.

One main takeaway is this effect occurs at different times around the world–within the US, different states will experience flooding in different decades. Federal mitigation efforts can be focused on regions that would be impacted first. However, by the 2030s, most seacoasts will be flooding at least on occasion due to extreme high tides.

The other effect predicted is, per year, the extreme high tide days will cluster together within a month or so in each region. They mention this because policy or planning for these types of extreme events usually think about it in terms of single isolated events, but this model predicts short “seasons” of extreme tides. Future mitigations should take that into account.

saboot2• 5 years ago

No problem, this article is being shared on other news sites now. And it's genuinely confusing to me why the original nature article isn't linked, or why Figure 2 isn't shown in any of them. The figure speaks for itself and even looks very nice. I don't understand reporting on scientific news.

EDIT: Actually axios linked to the original article, so good for them https://www.axios.com/nasa-moon-wobble-coastal-flooding-c462...

jmkni• 5 years ago

Is it only the United States?

swader9992• 5 years ago

No, its the moon too.

musiciangames• 5 years ago

Off topic, but how are these OneTrust cookie settings GDPR compliant? I though there had to be a way to opt out of these?

Link different devices Always Active Different devices can be determined as belonging to you or your household in support of one or more of purposes.

dublin• 5 years ago

Still trying to figure out how fracking, eating meat, and SUVs can possibly affect the Moon's wobble....

Moon wobble to bring surge in coastal flooding in 2030s, NASA study predicts

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