Claim: Marine heatwaves becoming more intense, more frequent

Thinning surface layer of ocean leaves waters more susceptible to extreme warming events

UNIVERSITY OF COLORADO AT BOULDER

Research News

IMAGE
IMAGE: BLEACHED CORALS FROM WARM OCEAN WATER TEMPERATURES. view more CREDIT: NOAA

When thick, the surface layer of the ocean acts as a buffer to extreme marine heating–but a new study from the University of Colorado Boulder shows this “mixed layer” is becoming shallower each year. The thinner it becomes, the easier it is to warm. The new work could explain recent extreme marine heatwaves, and point at a future of more frequent and destructive ocean warming events as global temperatures continue to climb.

“Marine heatwaves will be more intense and happen more often in the future,” said Dillon Amaya, a CIRES Visiting Fellow and lead author on the study out this week in the Bulletin of the American Meteorological Society‘s Explaining Extreme Events. “And we are now understanding the mechanics of why. When the mixed layer is thin, it takes less heat to warm the ocean more.”

The mixed layer–the water in which temperature remains consistent–blankets the top 20-200 meters of the ocean. Its thickness is responsible for heat events: the thicker it is, the more the layer can act as a buffer to shield the waters below from incoming hot air. But as this armor thins, the mixed layer becomes more susceptible to rapid swings in temperature.

“Think of the mixed layer as boiling a pot of water,” said Amaya. “It will take no time at all for an inch of water to come to a boil, but much longer for a pot filled to the brim to heat through.”

Amaya and his team used a combination of ocean observations and models to estimate the depth of the mixed layer back to 1980, and also project out into the future. They determined that over the last 40 years, the layer has thinned by nearly 3 meters (9 feet) in some regions of the North Pacific. And by 2100, the mixed layer will be 4 meters (12 feet) thinner–30 percent less than what it is today. This thin mixed layer combined with warmer global temperatures will set the stage for drastic swings in ocean temperatures, leading to much more frequent and extreme heating events, the researchers say.

And it’s already happening. Take the 2019 heatwave in the Northeast Pacific. Weakened winds and higher air temperatures came together to warm Pacific Ocean waters by about 3 degrees C (5.5 F). A thinning mixed layer most likely contributed to this surge of warm waters, the authors found. And it will get worse.

“If you take the same wind and ocean conditions that occurred in 2019 and you apply them to the estimated mixed layer in 2100, you get a marine heatwave that is 6.5 degrees C (12 F) warmer than what we say in 2019,” said Amaya. “An event like that would absolutely devastate sensitive marine ecosystems along the U.S. west coast.”

Amaya also points out that, as climate continues to warm and the mixed layer continues to thin, scientists might start to lose the ability to predict year-to-year ocean surface temperatures. Without the ability to accurately forecast ocean temperatures, fisheries and other coastal operations could be in danger.

Other studies also suggest marine heatwaves will become more common in the future, but not many have explored the root cause: ocean dynamics and physics. “In order to simulate these events in models and help predict them, we must understand the physics of why that’s happening,” said Amaya.

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John in Oz
January 31, 2021 10:15 pm

the more the layer can act as a buffer to shield the waters below from incoming hot air.

“Think of the mixed layer as boiling a pot of water,” said Amaya. “It will take no time at all for an inch of water to come to a boil, but much longer for a pot filled to the brim to heat through.”

Could someone with more knowledge than I explain how the air heating the ocean is the same as an intense heat source under a saucepan?

StephenP
Reply to  John in Oz
February 1, 2021 12:46 am

Who pays for this ‘research’?
It all seems to have been a jolly holiday.
Willis’s hypothesis of the way thunderstorms help keep temperatures relatively stable seems to have more traction.

Scissor
Reply to  StephenP
February 1, 2021 5:24 am

U.S. taxpayers pay via CIRES Visiting Fellows Program (indirectly from Department of Commerce, as well as minor state of Colorado support) and the NASA.

Ron Long
Reply to  John in Oz
February 1, 2021 1:58 am

John in oz, do you mean you don’t use a hair-dryer to heat your bathwater?

Alan
Reply to  John in Oz
February 1, 2021 8:45 am

Well, seems like common sense. An inch of water will heat up faster than a full pot. The top layer of the ocean has always acted as a buffer to the lower depths. This article is the biggest discovery since…sliced bread?

Editor
January 31, 2021 10:17 pm

I cracked up when they said they used “ a combination of ocean observations and models” … straight to the circular file with that one.

w.


Mr.
Reply to  Willis Eschenbach
January 31, 2021 10:41 pm

Don’t they use the models to correct the observations?

fred250
Reply to  Willis Eschenbach
February 1, 2021 2:14 am

Would love to see the observations from 1980. 🙂

DonK31
Reply to  fred250
February 1, 2021 5:22 am

What we’re getting are observations from 1984.

Chris Hanley
January 31, 2021 10:47 pm

Initially I thought the photo at the top could be an MRI of Biden’s brain.

fred250
Reply to  Chris Hanley
February 1, 2021 2:55 am

Nope, WAY too much live matter. !

Smart Rock
Reply to  fred250
February 1, 2021 7:38 am

And no sign of the bionic implants, either.

Ken Irwin
January 31, 2021 11:07 pm

 
If you consider man’s total energy output of ± 3.5 x 1020 J per year and we dumped all of this energy into the oceans (1.35 Billion cubic kilometres), it would raise their temperatures by ±0.00006°C an immeasurably small amount. Even if we magically dumped the thermal output of the world’s remaining fossil fuels (i.e. the next 450 year’s worth of fossil fuel use at current consumption) into the oceans overnight it would raise its temperature a barely detectable 0.028°C – the Boyle’s Law equivalent of the temperature gradient you might expect between the top and bottom of a flight of steps.
 
Do the maths – I dare you !
 
Yes I know it is unfair to use the entire oceanic mass, alarmists counter that only the top 30m is the “overturning” part of the oceans.
 
https://wattsupwiththat.com/2020/11/24/the-u-s-national-temperature-index-is-it-based-on-data-or-corrections/
 
But the entire oceanic mass overturns in 300-1500 years so at climatic timescales there is little to fault in using the entire mass. Even the top 30m has 25-30 times the energy contained in the atmosphere per degree Centigrade.

So if somehow, magically we were able to dump all the energy man has ever made from fossil fuels since our caveman ancestors first mastered fire – until we run out, we would raise the temperature of the oceans by 0.03°C

What me worry ?

commieBob
Reply to  Ken Irwin
February 1, 2021 1:33 am

You make a very good point.

Even if the mixed layer in part of the ocean has changed thickness, that doesn’t mean it was caused by a warming climate. In terms of ocean cycles, forty years is a relatively short time. It’s also quite possible that parts of the oceans have a thicker mixed layer.

If you do a web search for climate models “unphysical” you get many hits. Why does this matter, you ask.

A valid climate model would result from the use of physics and initial conditions. It could be run and would produce accurate predictions.

As far as I can tell, all of the climate models are unphysical somewhere under the hood. All of them have to be tuned. That means they are little better than curve fitting exercises. When tested against the basic laws of physics, as you have done, they come up short.

AndyHce
Reply to  Ken Irwin
February 1, 2021 2:27 am

The amount of energy people use, or can produce with current technology, it totally inconsequential in the heat/energy balance of the planet. In other words, how much, or how little, humans could directly heat the oceans has nothing to do with ocean temperature except perhaps in the immediate location of a power plant or some other largish industrial operation using ocean water as coolant.

I suspect the same is true in terms of any indirect human efforts such as producing more CO2, but that is a totally different question than the direct effect of human energy use.

Reply to  Ken Irwin
February 1, 2021 6:06 am

If the top layer of the ocean is thinning, then the planet must be cooling since there’s less energy available to maintain its thickness. If you’re going to worry about anything, I would wait until a km thick glacier is inevitably bearing down on Manhattan, as it has many times in the past and will inevitably do again regardless of how much CO2 we can emit.

The way that ocean waters overturn is through precipitation which is what drives the thermohaline circulation. There’s a net transfer of water from the equator to the poles via precipitation. At the poles, cold water sinks and the hydraulic pressure pushes the water at the tropics up from the bottom to replace evaporated water that ended up falling as precipitation at the poles. The deep ocean will never have any net warming until there’s no cold water at the poles to back fill evaporated tropical waters from the bottom.

Reply to  Ken Irwin
February 1, 2021 1:54 pm

Ken,
Much appreciated.
I repeat a bit of a mantra of mine – these wonderful ‘scientists’ have no appreciation of how big the planet’s Oceans are.
A bit over 120,000,000 square miles.
Average depth – a bit over two miles.
So – for back of an envelope sums – a quarter of a billion cubic miles.
Roughly a billion cubic kilometres of water.

Big – as you plainly appreciate.
Dillon Amaya – maybe less so.

Auto – forty five years in shipping, so I’ve seen a fair bit of water.

ATheoK
Reply to  Ken Irwin
February 1, 2021 4:32 pm

Aye, Ken!

And it’s already happening. Take the 2019 heatwave in the Northeast Pacific. Weakened winds and higher air temperatures came together to warm Pacific Ocean waters by about 3 degrees C (5.5 F). A thinning mixed layer most likely contributed to this surge of warm waters, the authors found. And it will get worse.”

It also sounds to me that these yahoos are assigning the temperature change of the top 20-200 meters to a much thinner surface layer.
That is, the heat energy content of 200 meters of ocean water are transferred to an ocean surface 2 meter layer.

Nor do these yahoos explain how a thinner layer of warmer ocean surface allegedly carries enough energy to significantly warm the atmosphere.
Let alone, explain how that this surface layer of 30°C (86°F) causes “heatwave”…

Much alarmism, little common sense makes for daft claims.

Climate believer
February 1, 2021 12:41 am

From the actual article in the BAMS:

“The anthropogenic contribution to these observed MLD (mixed layer depth) trends is less clear. There is model uncertainty in the strength and pattern of the estimated forced NEPac trends from 1980–2015.”

Less clear? model uncertainty?…. report for wrong think reprogramming immediately.

Mr. Lee
February 1, 2021 12:54 am

Just look at the language here:

the thicker it is, the more the layer can act as a buffer to shield the waters below from incoming hot air. But as this armor thins, the mixed layer becomes more susceptible to rapid swings in temperature.

buffer, shield, incoming, armor, susceptible — all describing water

Reply to  Mr. Lee
February 1, 2021 1:14 am

War talk, the favourite passtime of scared nerds sitting in mom’s basement plotting revenge on a cruel world that won’t give them the respect they damn well deserve…

fred250
Reply to  Mr. Lee
February 1, 2021 2:03 am

Incoming hot air….

Causes evaporation. !

….. and where is this “incoming hot air meant to be coming from ?

This reads like a Mills and Boon fantasy story, not science. !!

Meab
Reply to  Mr. Lee
February 1, 2021 9:37 am

I used to swim in a very large and deep lake every day in the summer. On calm days the surface was very warm but if you dove down just a few feet it would be much colder – maybe 10 or more degrees colder. On windy days the surface layer would be just as cold as deeper water – a combination of the wind enhancing evaporation and also mixing the warm surface water into the depths. Any putative change in the thickness of the ocean’s mixing layer has nothing to do with the atmospheric temperature. If the mixing layer is thinning, which I seriously doubt, it would be from changes in wind plus other circulation processes that overturn the ocean. Besides, the hotter the surface layer the more it radiates heat back into space. This paper is just more climate alarmist carnival barking.

A C Osborn
February 1, 2021 1:30 am

So now “hot air” is heating the first 20 metres of the ocean.

It sounds like a lot of hot air to me.

Iain Reid
February 1, 2021 1:46 am

I can’t grasp the concept of thick or thin layers in a body of water.
This explanation is surely wrong:- ““Think of the mixed layer as boiling a pot of water,” said Amaya. “It will take no time at all for an inch of water to come to a boil, but much longer for a pot filled to the brim to heat through.”

It is to do with the mass of water not it’s ‘thickness’ although that is proportional, but you cannot describe the oceans to have layers of water when there is any depth?

fred250
February 1, 2021 2:06 am

““Think of the mixed layer as boiling a pot of water,”

.

So its being heated from below is it ?

That is how I have always boiled a pot of water.

Maybe it Trenberth’s “missing heat” making it invisible presence felt somehow ????

So confused by their “fizzics”

fred250
February 1, 2021 2:13 am

“scientists might start to lose the ability to predict year-to-year ocean surface temperatures.”

.

And when did they magically get this ability ?

Only actually been able to measure it even partially since about 2003. !

What a moronic statement for them to make

NOT SCIENCE. !!

observa
Reply to  fred250
February 1, 2021 4:33 am

Just letting you know their predictions might be wrong in future but you’re still doomed boyoh.

Tim.
February 1, 2021 2:19 am

What is this “skin”? We have a skin on our ponds at present which has been there some days. It’s called ice. I would guess that is due to the heat in the water going into the air.

Climate believer
Reply to  Tim.
February 1, 2021 3:07 am

That would be moonflower ice, created by unicorn breath, I have heard tale of such sorcery far to the North.

Peta of Newark
February 1, 2021 3:22 am

How is it possible to be so dumb..
Quote:
“”but a new study from the University of Colorado Boulder shows this “mixed layer” is becoming shallower each year””

Surely Shirley, if Global Warming Changing Change was actually doing what it is supposed to be doing AND actually is doing according the ever more massive Super Computer, viz: creating more and ever more super massive than massively super things.
then,
This Mixed Layer must be getting more mixed and thus thicker
The extra (heat) energy being trapped by GHGs must go to creating more turbulence.
Yet it creates less
seemingly

Am I missing something here or is White really the New Black – how do they get away with relentlessly trashing their own science?
how

Tim Twombly
February 1, 2021 3:39 am

Models eh? As I recall, models predicted NYC under water by 2010.

Vuk
February 1, 2021 5:16 am

Boris Johnson’s father Stanley has landed a new environmental job. His new role is as international ambassador of the Conservative Environment Network, a group of 100 MPs and peers.
In his role, Mr Johnson Snr will attend the United Nations COP26 climate change conference in Glasgow in November.
He said he will ‘constructively’ call for policies including carbon taxes, which raise the price of goods producing more of the greenhouse gas carbon dioxide.

Last edited 26 days ago by Vuk
Keith Rowe
February 1, 2021 6:56 am

Perhaps the thinning ocean and warm period is because the warm water is being pushed/pulled into the arctic and antarctic waters as the push down of waters in Antartica and Arctic Oceans that push up waters in the Pacific causing this cycle of warming, thinning and and abrupt cooling. The building up of heat and stratification of equatorial oceans and once again starts as the northern/southern oceans cool. One can see other evidence of this by the upwelling in about 1850’s in the Pacific that increase the food available.

Smart Rock
February 1, 2021 7:36 am

And it will get worse

Now where have I heard that before?

DMacKenzie
February 1, 2021 7:58 am

So the cold layer must be getting thicker, right ?

Walter Sobchak
February 1, 2021 8:00 am

“Amaya and his team used a combination of ocean observations and models”

Models == GIGO.

The Oceans are neither heated not colled by the air above them. water has a specific heat of 4.2. The air above the oceans is heated or cooled by the oceans

Richard Page
February 1, 2021 11:07 am

Unsupported opinion or observed data?

John Harrison
February 1, 2021 4:04 pm

“In order to simulate these events in models and help predict them, we must understand the physics of why that’s happening,”
Please give us more research funding

Ulric Lyons
February 1, 2021 7:37 pm

“Take the 2019 heatwave in the Northeast Pacific.”

Driven by negative Arctic Oscillation conditions like also with the 2013 warm blob, they are bound to be more frequent during a centennial solar minimum.

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