Offshore Wind Farms Altering Marine Ecosystems: “Sufficiently Potent to Redirect Existing Currents”

From the NoTricksZone

By P Gosselin

Wind Turbines are causing climate change

Hat-tip: Klimanachrichten here

It’s ironic: Man is changing the environment and climate in order to prevent change.

Atmospheric wakes extending from the bottom to the top of the picture [contains modified Copernicus Sentinel data (Sentinel 2A-MSI 29/03/2021), processed by ESA & Hereon/ Dr Martin Hieronymie]

Researchers from the Hereon Helmholtz-Zentrum have found shifts in airflows and sea currents, which are connected to offshore wind farms.

A team led by Nils Christiansen recently published a research paper about the impacts offshore wind farms have on the ocean dynamics, published in the journal Frontiers in Marine Science. Press release here.

“Wind speed deficits spread up to 70 km behind the wind farms”

The turbines extract kinetic energy from the wind field to generate electricity. Downwind of the wind turbines, the so-called atmospheric wakes develop, and are characterized by reduced windspeed, specific pressure conditions and enhanced air turbulence. During stable atmospheric circumstances, the wind speed deficits spread up to 70 km behind the wind farms.

Using high-resolution hydrodynamic computer simulations, the team analyzed the effects on the southern North Sea for the summer of 2013 (May to September). The analysis shows a link between atmospheric wakes and transformation in the momentum-driven exchange between the atmosphere and water. As a consequence, the horizontal currents and the stratification of the water could be affected.

Redirecting existing currents

The wake effects are sufficiently potent to redirect the existing currents, and thus results in shifting mean temperatures and a changed salinity distribution in the wind farm areas.

“While the occurring changes remain within the range of interannual variability, they illustrate similar magnitudes as the presumed mean changes due to climate change or year-to-year variability,” says Nils Christiansen, from the Hereon Institute for Coastal Systems, who was lead author on the study.

Reduced water surface turbulence

Another wake effect is the reduction of shear-driven processes at the sea surface. In other words, the turbulent mixing of the water surface caused by shear wind is reduced dozens of kilometres around the wind farm. Water is usually stratified, thus a layer of warmer water may lie on top of a layer with cold water. Wind farms disturb this natural stratification. Due to reduced mixing, a stabilized stratification of the water is fostered. This phenomenon was particularly noticeable during the decline in summer stratification.

The natural stratification of the water is especially prominent in summer and decreases towards autumn. In the area of the wind farms, however, a stabilized stratification outside the seasonal variation was measured.

“The magnitude of the induced mean changes does not indicate severe local effects, however far-reaching structural changes in the system occur“, says Christiansen.

“Far-reaching structural changes in the system”

“The transformation concerning currents and mixing are likely to affect plankton production and the food web structure. As a result it may influence the function of protected areas. Hence it is important to consider these consequences while developing marine protection concepts“, says Hereon Institute Director Prof. Corinna Schrum.

Moreover, possible feedbacks on air-sea exchange potentially affects regional atmospheric conditions and ecosystem dynamics.

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August 20, 2023 2:09 pm

Everything has an effect, predictable or not…

Reply to  atticman
August 21, 2023 2:32 am

As Newton proved, to every action………………………….

Reply to  atticman
August 21, 2023 9:17 am

I have one tiny motivational poster in my study, a simple black-on-white:
“In Nature, there are no punishments or rewards, only consequences.”

Reply to  cilo
August 21, 2023 11:13 am

re: ” … only consequences.

Mine would say ” … only trade-offs.” But hey- I’m an engineer not a lawyer.

Christopher Coulter
Reply to  _Jim
August 22, 2023 6:22 pm

Even more succinctly: TANSTAAFL

Reply to  Christopher Coulter
August 24, 2023 8:20 am

“Somebody has to pay the freight.” was the term I used years ago.

August 20, 2023 2:40 pm

What I want to know if wind turbines act as artificial reefs the way oil and gas platforms do. In other words, what is the effect of infra-sound on sea life.

Reply to  Fran
August 21, 2023 11:14 am

Deaf fish (as well as other wildlife)? I wonder if they can suffer ‘sleep deprivation’ too …

Reply to  Fran
August 21, 2023 1:31 pm

Possibly all the recent whale deaths from LF infrasound & sonar survey equipment, if anyone (other than big wind) bothers at some point to actually investigate

August 20, 2023 3:10 pm

Moreover, possible feedbacks on air-sea exchange potentially affects regional atmospheric conditions and ecosystem dynamics.

There is a huge amount of energy in air flow across the globe. It is measured in kilowatts per square metre of stream flow so; up to three orders of magnitude higher than the delicate radiative heat transfer that gets so much attention.,-11.45,372/loc=-92.996,-33.270

What is not known is the time it takes to get all that kinetic energy into the air flow. The heat engine that drives global circulation through the Hadley cells has low Carnot efficiency. It takes around 190W/m^2 of surface sunlight at the base of the cells to create convective potential that averages around 11W/m^2 of surface area. The convective engine is not very efficient. The potential energy gets converted into kinetic energy of the airflow.

Wind turbines are designed to extract up to 59% of the energy in the near surface air stream that transports most of the moisture. How much energy can be robbed from a coastal airstream before it reduces enough moisture advection from ocean to land to have a local climatic impact? No one knows.

Nothing on Earth comes for free. Wind energy is currently viewed as an infinite resource that has no cost. Is this really the case? How much of Europe’s record July heat is attributable to air stilling due to the growing number of wind energy extractors? Does Arizona have a case against Texas and California for robbing the wind energy and the moisture it carries?

Reply to  RickWill
August 21, 2023 1:29 am

“Nothing on Earth comes for free.”

But Nick keeps telling us that wind is free!

Reply to  DavsS
August 21, 2023 11:16 am

Nick works with highly constrained systems (and system’s knowledge); think straight jacket, but for thinking.

Christopher Coulter
Reply to  RickWill
August 22, 2023 6:24 pm

Nothing on Earth comes for free.

Nuclear power comes pretty darn close

Reply to  RickWill
August 22, 2023 11:38 pm

“What is not known is the time it takes to get all that kinetic energy into the air flow”
There is no “time it gets”. One speaks about power and total energy balance.
According to NASA 5% of total solar irradiance (TSI) goes into “convection” – that is the source of wind.
TSI is 1361 W/m2, this amounts to 3.14*6.4e6*6.4e6*1.361e3 = 150 PW solar power reaching the Earth (1PW = 1e15 W)
5% of that or 7.5 PW goes into “convection”
Convection is a Carnot cycle. The hot air rises up, cools down, goes down: the Hadley cells appear.
The Carnot cycle efficiency of converting thermal energy into the wind kinetic energy is (Th-Tc)/Th. As we are interested in horizontal winds, the Th-Tc is the temperature difference between the tropics (Th) and the mid latitudes (Tc). Th-Tc is about 10K, Th = 300 K. Thus, the maximum available kinetic wind power is 7.5PW/30 = 250TW (1TW = 1e12W)
Mention, this wind kinetic power is NOT just for us.
It must sustain the ocean currents and it carries moisture!
Any wind energy extraction at significant power levels will influence the oceanic currents and the global (as well as local) climate.
BTW Germany alone (!) plans to install 0.4TW offshore wind power farm in the North Sea.
Which consequences will it have?

Rud Istvan
Reply to  J Boles
August 20, 2023 3:26 pm

Covered this more thoroughly than Am Thinker in a longish comment to the recent Lomborg thread.

August 20, 2023 3:24 pm

> Researchers from the Hereon Helmholtz-Zentrum have found shifts in airflows and sea currents, which are connected to offshore wind farms.

No they haven’t:

Using … computer simulations, … could be affected.

Alexy Scherbakoff
Reply to  StuM
August 20, 2023 5:24 pm

I’m sceptical of all models and try not to be caught up in confirmation bias.

Reply to  Alexy Scherbakoff
August 20, 2023 10:38 pm

I’m sceptical of all models and try not to be caught up in confirmation bias.

The authors describe how they validated their models in the original paper and claim:

high correlation (R > 0.9)

All models are wrong, but some are useful.

~ George Box

Dave Fair
August 20, 2023 3:30 pm

Nobody escapes the law of unintended consequences. Voters continue to buy into the pie-in-the-sky politicians’ green utopias.

August 20, 2023 4:31 pm

Noticeable effects of disruptive air disturbance have been observed (tragically) since the age of powered flight of large aircraft.

Isn’t this why take-off and landing intervals are required at airfields?

If unnatural air disturbance can bring down a passenger jet, Shirley such unnatural air disturbance can cause sea surface disruption?

Reply to  Mr.
August 20, 2023 7:56 pm

Stop calling me Shirley? A funny movie that could not be made today.

Peta of Newark
August 20, 2023 5:15 pm

quote:The turbines extract kinetic energy from the wind field

What is a ‘wind field‘ – apart from bafflegab?

The authors don’t seem to understand the photo they have shown of the ‘wakes’. In fact, they completely don’t.

The visible wakes are condensation droplets of water.
Those droplets are caused by a rapid pressure drop and thus temperature drop as the air encounters the turbine blades.

If you’re quick, observant, at an air-show and of ‘enquiring mind‘, you might see something like the attached
More of the same here

It is the same effect as the turbines demonstrate in the picture and explains how they really work

IOW: Wind turbines work by cooling the air. That is where the energy they extract comes from
Insane as it seems, they are the exact same principle of any and every Heat Engine – you extract energy by cooling a gas.
They turn heat energy in the air into mechanical motion (their own rotation) and then immediately turn it into electricity
Slowing the air down and turbulence are ‘side effects’

quote:“stable atmospheric circumstances
What are these, is there anywhere at anytime on this Earth when ‘the atmosphere is stable’
Surely Shirley, if the atmosphere was stable it would not be moving (windy) and thus, neither would the windmill

quote:”Wind speed deficits spread up to 70 km behind the wind farms
I’m sorry people but this is a massive exaggeration of what humanity has learned about ‘windbreaks’ since humanity first ever noticed ‘wind’ and had to cope with and endure it.
The ‘wind speed deficit‘ is only noticeable for a distance equal to ten times the height of the windbreak or the wind obstruction.
This 70km might apply if windmills were 7,000 or more metres tall

In any case, where does the wind (that went through the turbine) ‘go’ while it’s slowed down and forced into catching up with the rest of the wind?
In fact, if it is ‘going slower’. how does it ever catch up? The authors thus suggest that wind turbines somehow create an ever growing ‘pile of slow air’.
I mean, just what??!!!

This article is Kindergarten Science backed by the authority of A Computer.
IOW Perfect Climate Science.
Do try in future to keep away from those people, junk science is obviously infectious.

Reply to  Peta of Newark
August 20, 2023 7:11 pm

They turn heat energy in the air into mechanical motion (their own rotation)

This is incorrect. The energy extracted from the wind is entirely related to the momentum of the wind. Nothing to do with thermal energy.

The paper at this link goes through the derivation of power output from the wind kinetic energy as well as deriving the Betz Limit:

Reply to  RickWill
August 20, 2023 8:03 pm

Yes, argumentative and I was going to skim past it, but yes and verifiable with thermometers.

Reply to  Peta of Newark
August 21, 2023 12:07 am

May be, you should first learn hydrodynamics and the term “boundary layer”?

The offshore windmills are 200-300m tall.
Sounds small, but this is enough to influence the total atmospheric flow up to 10 km height.
Actually, the boundary layer is why YOU will never swim as fast as dolphins.
Your skin is too soft and vibrates just a few millimeters in water.
This defines the boundary layer drag.
It is enough to stop your body.
Dolphins skin is hard like beton.
They do not have this boundary layer and swim very fast.

Also, that is why the winds blow fast over the see or flat surfaces: there is little to create the stopping boundary layer.
Already low trees can modify the wind patterns greatly.

Reply to  Peta of Newark
August 21, 2023 1:57 am

Peta of Newark, you need to retake your high school science, especially physics and earth science.

First, there’s a pressure INCREASE as the air encounters the wind turbine blade, that’s the push that moves the blade. Equally as important is the low pressure side of the blade, as the air leaves the blade, which creates low pressure immediately behind the blade and makes the high pressure side push more effective. Ask anyone who sails (not motor boats) just how effective this can be.

Any time there is a pressure change in air, there is a related temperature change, but that is not the driving force of wind turbines. That you believe it is, pretty much proves you’re our of your depth in this discussion.

BTW, it’s the same basic thing happening with the jets (cool pics, thanks for those), but it’s apples & oranges to compare a jet going 400+ mph (potentially 700+ mph) with those very wide wings, meaning LOTS of surface area, with a far more narrow wind turbine blade doing ~200 mph.

You might be interested to know, there have been studies for years showing how large land-base wind farms, like those in TX, have large enough effects that they impact precipitation, ground temperature, and wind, downstream of the wind farms, for at least 20 miles, and potentially up to 50 miles.

Regarding your asertion that wind breaks don’t affect downstream more than 10 time their height. I would really like to know where you got that. How is it that a 3 meter tall snow fence has a snow drift extending over 100 meters downwind of it?

The bottom line, it’s all about energy, whichis never destroyed, it just changes form. The wind turbine removes some of the energy from the wind, imparting it through the blades, to the shaft, generator, where it’s turned into electricity.
Does that wind ever regain that energy the turbine blades removed, I’m sure it does at some point, but that energy has to be taken from other wind or another process that drives wind creation.

The point of the article/study is that taking this wind energy has effects that are not well understood, maybe not at all understood, so it’s misleading at least, possibly completely wrong, to say wind turbines are environmentally friendly energy generation.

Without 100% perfectly accurate data, models are never correct, but with reasonably accurate data they can provide indications that require more investigation.

As someone who has been working in/with the govt. in energy for over 15 years (after 20 in the military, so I do know a little about aerodynamics, hydrodynamics, and general physics), I keep saying, it all goes back to a pysics lesson we all used to learn in grade school, “for ever action there is an equal and opposite reaction.”
Everything humans do is an action on the planet, so there will ALWAYS be a reaction, an effect, of our action. It’s highly unlikely one effect will be much better or worse than another, just different.

Reply to  Peta of Newark
August 21, 2023 7:33 am

The condensation droplets are in the wake, and show where the wake is.

August 20, 2023 7:37 pm

Build new fossil fuel and nuclear generators and remove all wind and solar from the grid.

Reply to  Bob
August 21, 2023 2:37 am

I’m with you Bob

August 20, 2023 7:50 pm

Ocean big, windmill small.
Though I do wonder whether we could repurpose the windmills to make surfing waves.

August 20, 2023 11:53 pm

Well. Was there smth about “butterfly effect”?
This “butterfly” is a bit too large

August 20, 2023 11:57 pm

The wind IS our climate.
Those who stop the wind, they destroy our climate.
Exploiting wind energy must be prohibited internationally world wide…
except this will never happen.
The wind power market is about $500 billion globally

Reply to  alexbuch
August 21, 2023 2:38 am

I wonder if alarmists have modelled the effect of all these wind turbines on the earths rotational speed?!

Reply to  Energywise
August 21, 2023 7:37 am

Shouldn’t be any. All wind stops eventually.

Reply to  MarkW
August 21, 2023 12:31 pm

well, the question is where do they stop

August 21, 2023 12:13 am

Using high-resolution hydrodynamic computer simulations, the team analyzed the effects on the southern North Sea for the summer of 2013 (May to September). The analysis shows a link between atmospheric wakes and transformation in the momentum-driven exchange between the atmosphere and water. As a consequence, the horizontal currents and the stratification of the water could be affected.

This doesn’t sound convincing to me.

Did they find evidence of current deviations downwind from the turbines, relative to a control area, or not.
Same question for the surface shear.

Reply to  MCourtney
August 21, 2023 1:39 am

Agreed, it’s that dreaded word ‘could’.

August 21, 2023 2:31 am

Not only are off shore wind farms adversely affecting the marine eco systems, including killing whales etc with sonar surveys, the on shore wind farms are affecting agricultural eco systems, drying out land and disturbing the biosphere, as well as killing birds, bats etc
As a national energy source, they are the most stupid of stupid man made things

August 21, 2023 2:32 am

One day, people will look back and just laugh, a bit like how we do today at the flat earthers or witch burners

August 21, 2023 3:24 am

You can’t beat the Second Law of Thermodynamics.

Jim Gorman
August 21, 2023 4:12 am

Unknown unknowns!

August 21, 2023 8:23 am

Probably heard this somewhere in engineering school back in the 1950s: You can never do just one thing.

August 21, 2023 12:46 pm

This article is nonsense. What is occuring here is condensation forming behind the nacelle from heat with the right conditions to form. Light breeze and no cloud or mist upwind of the turbines so this would be having no effect on the water or air miles away

Reply to  R.K.
August 21, 2023 1:33 pm

Is that you Dale?!

Reply to  R.K.
August 21, 2023 4:46 pm

Assertion w/o cite; comment pretends to present an alternate scenario not in keeping with reality.

B Zipperer
Reply to  R.K.
August 21, 2023 10:38 pm

“…no effect on the water or air miles away”.
So you think the turbine doesn’t cause any downwind turbulence?
The water vapor condensation makes the turbulence visible.[a turbine “shadow” that can lower efficiency for downwind turbines, as is likely happening in this photo].
As to distance, a field of turbines would seem quite capable of affecting wind speed several miles away but I don’t recall a rule of thumb for it.
See Rick Will’s link from his comment above for details on the whirlpool effect of the blades downwind:

Reply to  B Zipperer
August 22, 2023 4:16 pm

What I was commenting on was what was happening in the photo. There is no mist or fog upwind of the turbines and it starts some distance behind the nacelles on all of them. It can only be moist air rising into heated air behind the nacelles and it streams at a unform rate and height behind each turbine indicating calm conditions with a light breeze.Wind turbines would not affect wind speeds several miles away because air never flows over land at a constant speed or direction once the wind speed rises. Turbulence occurs around all objects and terrain and only about 10% of the wind is contacted in the blade turning area.
The photo does not provide evidence for what the authors are saying.

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