CLAIM: Expect fewer, but more destructive landfalling tropical cyclones

From the INSTITUTE FOR BASIC SCIENCE and model madness department.

A study based on new high-resolution supercomputer simulations, published in this week’s issue of the journal Science Advances, reveals that global warming will intensify landfalling tropical cyclones of category 3 or higher in the Indian and Pacific Oceans, while suppressing the formation of weaker events.

Tropical cyclones (including typhoons and hurricanes), are the most fatal and costliest weather disasters on our planet. Millions of people are affected every year by the destructive power of these extreme weather systems, but how tropical cyclone properties – in particular in coastal areas – will change in response to global warming has long remained a mystery. To address this question, scientists for over two decades have used the world’s largest supercomputers to run climate model simulations that show important aspects of these destructive storms. However, until recently the computing power has been insufficient to capture both atmospheric details and resolve the full interaction with the ocean on a global scale.

Rainbands (white) of a tropical cyclone and related ocean cold wake (colored shading) simulated by the ultra-high resolution climate model simulation for present-day conditions (left). The simulation was conducted with the IBS supercomputer Aleph (right), located in Daejeon, South Korea. CREDIT IBS

A team of researchers from South Korea’s IBS Center for Climate Physics (ICCP) at Pusan National University recently completed one of the most computing-intensive and detailed global warming simulations so far. The global climate model records small-scale atmospheric and oceanic processes with a horizontal scale of 25 km and 10 km, respectively. This unprecedented resolution is adequate to simulate tropical cyclones and oceanic cold wakes (Fig. 1), which are generated when a strong slowly moving tropical cyclone brings cold deep water up to the ocean surface, further influencing the track and intensity of tropical cyclones.

To determine the sensitivity of tropical cyclones to global warming, the research team ran computer model simulations for present-day atmospheric greenhouse gas composition and doubled and quadrupled CO2 concentrations. The simulations ran for 13 months on one of South Korea’s fastest academic supercomputers named Aleph (Fig. 1), generating an equivalent of about two-thousand 1TB hard disks of data.

This climate computer model is also unique in other aspects. For example, it exhibits much weaker ocean temperature errors than the previous generation of climate models. “This improvement was important for a realistic simulation of typhoons in the Indian and Pacific Ocean” says Dr. Jung-Eun Chu, lead author of the study and a project leader at the ICCP.

Over the warm tropical oceans, air rises, flowing polewards at high altitude and sinking in the subtropical regions. The surface-return-flow of this so-called Hadley circulation feeds the global trade wind system. According to the new study, the summer-time Hadley circulation is expected to weaken in future due to the accelerated atmospheric warming at an elevation of 5-15 km, relative to the ground. “A future reduction of rising motion in the tropical atmosphere will make it more difficult for tropical cyclones to develop, which explains the projected future suppression in tropical cyclone seeds and overall numbers in the Pacific and Indian Ocean (Fig. 2)”, explains Dr. Sun-Seon Lee from the ICCP, who conducted the simulations on Aleph. “Interestingly the simulated pattern of future tropical cyclone changes is quite similar to the recent observed trends, which supports the notion that global warming is already altering global extreme weather” adds Dr. Lee.

However, the story how global warming will alter tropical cyclones is more complex. Although for a CO2 doubling the total number of tropical cyclones is expected to decrease in future, developing events will have much higher chance to intensify beyond category 3 due to the higher humidity and energy levels in the atmosphere. “This result confirms previous studies which used less-detailed global climate models. By representing coastal processes more accurately than ever before in a global model, we now have a much higher confidence in these robust model projections, in particular for landfalling tropical cyclones.”, says Prof. Axel Timmermann, co-author of the study and Director of the ICCP.

For even higher greenhouse gas concentrations (CO2 quadrupling), the research team discovered an important, previously unknown, saturation effect: beyond ~5? global warming, the suppression of tropical cyclone seeds is so strong that also the number of strong landfalling events (category 3 or higher) will begin to level off. “Nevertheless, the rainfall associated with each event will continue to increase, amplifying the risk for extreme coastal flooding. Our study provides crucial policy-relevant information for countries that are affected by the impact of tropical cyclones” says Dr. Chu.

The ICCP research team will continue to analyze the vast amount of data generated by these computer simulations to better understand the interaction between ocean heat content and tropical cyclones under present day and future conditions.

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From EurekAlert!

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lee
December 17, 2020 2:27 am

Wow. Models and quadrupling CO2. 😛

Joel O’Bryan
December 17, 2020 3:15 am

According to the new study, the summer-time Hadley circulation is expected to weaken in future due to the accelerated atmospheric warming at an elevation of 5-15 km, relative to the ground. “

Ah yes!! The observationally missing mid-troposphere tropical hot spot has once again been simulated.
Flogging the hot spot dead horse once again, koreanBBQ style this time.

December 17, 2020 3:27 am

(Ooooooh, shiny! I think I’m going to like this new look!!)

Meanwhile, God is running His own “simulation,” which we call “reality.” In that “simulation,” hurricanes and tropical cyclones are not worsening.

Here are a couple of papers:

Lin & Chan (2015), Recent decrease in typhoon destructive potential and global warming implications. Nature Communications, doi:10.1038/ncomms8182.

Klotzbach & Landsea (2015), Extremely Intense Hurricanes: Revisiting Webster et al. (2005) after 10 Years. Journal of the American Meteorological Society, doi:10.1175/JCLI-D-15-0188.1.

Here are a couple of graphs, from Dr. Maue:

http://climatlas.com/tropical/global_major_freq.png

http://climatlas.com/tropical/global_running_ace.png

Maue_global_running_ace_132pct_plus_global_major_freq_2020-11-30[1].png
DHR
Reply to  Dave Burton
December 17, 2020 5:29 am

These are extraordinary times. Normally, one would think that a year-long supercomputer simulation that failed to represent observations would be called a failure. Now it’s called a revelation.

Climate believer
Reply to  Dave Burton
December 17, 2020 10:02 am

Nevertheless, the rainfall associated with each event will continue to increase, amplifying the risk for extreme coastal flooding. 

Scaremongers, this is not happening in the real world.

https://ibb.co/kX0scPR

fretslider
December 17, 2020 4:07 am

<i>new high-resolution supercomputer simulations</i>

When are they going to do some real science?

Bill Powers
Reply to  fretslider
December 17, 2020 11:38 am

Its so much easier to tell the computer what science you want. Especially now since it can provide 3-D imaging for your desired outcome.

Joel O'Bryan
Reply to  Bill Powers
December 17, 2020 5:27 pm

Climate modeling is Feynman’s Cargo-cult science at a fine art of practice by the pseudoscience climate community. Those Cargo Planes will be landing any day now too. And the mid-troposphere tropical hotspot will appear any day now too.

Peta of Newark
December 17, 2020 4:15 am

First: How do they link ocean temp with CO2? The GHGE can not heat the water, only the sun can.. Less clouds maybe or Sol itself gets hotter.

Okaaaay, maybe the ocean water will get warmer with rivers running warmer, because of the lowered albedo of the land. What rain that does fall will be warmer.
Likewise if rain falling straight into the ocean (circa 1 metre per year) is falling through plumes of warm air blown off the land.
Both caused by tillage and deforestation. Both of which lift the level of CO2

Second and maybe I’m all wrong but…
The energy contained in a hurricane/storm is pretty well defined by its wind-speed – the classic half-em-vee-squared
But the energy dissipated by the storm (making waves, surges, blowing down trees & houses etc) will go as per the energy you get out of wind turbines – that is as per the cube of third power of the wind-speed

Thus all storms will exist and be moving on a graph between two rapidly converging lines – one of energy content ( a squared or quadratic curve) and their energy dissipation = a cubic curve.
Those two curves will intersect and the storm will find it utterly impossible to go beyond the intersection. They will be expending more energy than they have or are creating

So, why don’t current and past storms all run up against that intersection point and if they do, how do these folks claim they can get any stronger.
For the same reason, they can not get any bigger, to do so means the centre has to accelerate and it simply cannot, or it will collapse.

Oh wait, isn’t *that* what happens during ‘Eye-wall replacement’?
Thus the storms we all know and love already are at the very limit of their existence and these folks are talking Complete Garbage

MarkW
Reply to  Peta of Newark
December 17, 2020 10:41 am

If the air warms, then it is harder for the heat that the sun is putting into the water to get out.
As a result, the water warms.

John in Oz
Reply to  MarkW
December 17, 2020 1:41 pm

By that theory, water in a thermos flask, which is designed to retain the energy of its contents, would get warmer.

Cold in, hot out. I want one.

Steve Reddish
Reply to  John in Oz
December 17, 2020 10:05 pm

Water in a thermos is not being irradiated by the sun. Your thermos is not analogous to the ocean.

December 17, 2020 4:28 am

Here we go again with another whimsical “climate” model. What does the data show? I thinks its showing less storms. Otherwise, show me the verification data of this model — and then maybe it can be believable. Never trust a forecast from someone (or some thing) that never produced a forecast that verified.

Bob Hunter
Reply to  John Shewchuk
December 17, 2020 9:54 am

My go to phrase re computer modelling:
”never underestimate the motivations of the modellers band the assumptions they have made”

Bob Hunter
Reply to  Bob Hunter
December 17, 2020 9:57 am

’band’ s/d be — based on

Dave Fair
Reply to  John Shewchuk
December 17, 2020 10:12 am

How often did the programmers have to “renormalize” the run to keep it on the rails?

Joel O'Bryan
Reply to  Dave Fair
December 17, 2020 10:37 am

They’ll never tell you that. That’s info that supposed to stay behind the curtain.

Mumbles McGuirck
December 17, 2020 5:15 am

I note the press release carefully avoids saying how much stronger major hurricanes will be or how fewer of them the models create. Current simulations show a meager 5 m/s increase with a doubling of CO2. That’s well within the noise level of hurricane variability. So any decrease in number of storms is worth the unnoticeable increase in strength. But CO2 = BAD therefore we ignore such important details.
Of course, this all based on flawed computer models anyway. GIGO

Editor
December 17, 2020 5:40 am

The article starts, “A study based on new high-resolution supercomputer simulations…”

That’s as far as I needed to read to determine that the study is nonsense.

Regards,
Bob



eck
Reply to  Bob Tisdale
December 17, 2020 6:28 pm

Amen. Me too.

Tom in Florida
December 17, 2020 6:23 am

Has the code been made available?

“Fight climate change fear. Warmer is better.”

December 17, 2020 8:04 am

“A study based on new high-resolution supercomputer simulations…”

How does the first sentence of this article add legitimacy to the study?

All it tells me is that garbage in, garbage out can be calculated with higher resolution.

Don Thompson
December 17, 2020 8:23 am

Simulations do not reveal, they predict or project. Even supercomputer models need to be verified by comparison to observations, and this one apparently did not get that far.

Philo
December 17, 2020 9:03 am

Here we go again! COMPUTER MODELS are not reality. They are models, pure and simple, similar to an architect’s layout of a building. It represents a possible reality but has none of its characteristics.

There is a good deal of discussion in the scientific community about the usefulness of models- climate models, PCR virus models, seismic models, population genetics models, et al.

According to at least several prominent physicists working on physics models a model such as a climate model is many orders of magnitude away from a useful physics model. The precision required is somewhere beyond 10^6th orders of calculation precision. Even then, almost every conceivable model runs into the computer limits of accuracy- the smallest difference between two values that can be calculated- the machine epsilon.

The model,in order not to crash, has to maintain calculations some 10^-6 shorter than the computer calculation limits. That is critical just to get reproducible results by not stomping on the floating point calculations limits.

We won’t see this kind of computer accuracy until long after 2050. The resources, other than time, are exponentially far away- both in equipment and programming capabilities.

Philo

MarkW
Reply to  Philo
December 17, 2020 10:45 am

Models are useful in helping you figure out what it is that you don’t know. When models fail to match up with reality, that helps you figure out what areas need more research.

Coeur de Lion
December 17, 2020 9:05 am

CO2 increase since say 1900 from just under three molecules per ten thousand to just over four will need a couple of centuries to ‘double’. Current ECS calculations give c. 1.5 degsC eh? Relax

Walter Sobchak
December 17, 2020 9:50 am

“high-resolution supercomputer simulations”

Sort of like 4K porn for “climate scientists”.

They need to stop doing this or they will go blind.

Joel O'Bryan
Reply to  Walter Sobchak
December 17, 2020 10:38 am

They can go work for CNN apparently.

DMacKenzie
December 17, 2020 9:58 am

Why is it that the authors of these studies always appear to push to redouble society’s efforts to reduce C02 emissions, instead of redoubling their efforts to find out why their model is not correct to any reasonable degree of certainty ? Or is that mostly media spin ?

MarkW
December 17, 2020 10:38 am

present-day atmospheric greenhouse gas composition and doubled and quadrupled CO2 concentrations”

From everything I have read, doubling current CO2 concentrations is highly unlikely. Quadrupling it is pure fantasy.

Reply to  MarkW
December 18, 2020 1:25 pm

Unfortunately true.

Quadrupling CO2 from the current level would be about optimum for agriculture. But that would require an additional increase in CO2 level 9x as large as the modest 135 ppmv by which mankind has managed to increase it, so far — despite dwindling fossil fuel supplies, and negative feedbacks which remove CO2 from the atmosphere at an accelerating rate.

Even a mere doubling, to 830 ppmv, is almost certainly impossible.

Kevin McNeill
December 17, 2020 10:45 am

Data from a simulation is simulated data not real data

Robert of Texas
December 17, 2020 11:13 am

More destructive because there are more people and property in the way…

John in Oz
December 17, 2020 1:35 pm

I would be impressed with their predictions of the future if they can show how accurate their 2020 results are after using initial conditions with 1990 data.

ResourceGuy
December 17, 2020 1:55 pm

….mainly on Tuesdays.

RickWill
December 17, 2020 3:57 pm

This unprecedented resolution is adequate to simulate tropical cyclones and oceanic cold wakes (Fig. 1), which are generated when a strong slowly moving tropical cyclone brings cold deep water up to the ocean surface, further influencing the track and intensity of tropical cyclones.

Where is the evidence for this. The white fluffy clouds in the image even provide the clue. Cyclones can knock out 80% or more of ground level insolation. And they saturate the air between the surface and level of free convection. This results in surface cooling in their wake. If they cannot get this right then their model is garbage – no different too any other climate model.

Pat Frank
December 17, 2020 4:36 pm

<a href=”https://www.frontiersin.org/articles/10.3389/feart.2019.00223/full/”>Predictively useless</a> simulations with <a href=”https://wattsupwiththat.com/2020/10/27/cmip6-update/”>the newest most up-to-date models</a>, now provided faster and in more detail than ever!

The sudden modeling jumps of 2x and 4x CO2 are unphysical, by the way. The actual change averages about 1 ppmv per year, worth 0.035 W/m^2 forcing increase.

Every year the climate must adjust to (0.035/245) = 0.014% increase in forcing. This tiny impulse is what they’re screaming about. Very small changes in cloud cover or convection/condensation/precipitation can zero out the whole thing, resulting in no detectable change in sensible heat.

Last edited 2 months ago by Pat Frank
Mike
December 17, 2020 8:34 pm

Fewer but more destructive….
No need to say anymore.

Anders Valland
December 18, 2020 1:02 am

global warming will intensify landfalling tropical cyclones of category 3 or higher”

Maybe I am missing something here, but this is a strange statement. You cannot intensify a cat.3 hurricane. If was more intense, it would be a cat.4. Likewise for a cat.4. None of what they say would make a cat.3 hurricane more damaging than it already is.

So you are left with saying that a cat.5 might get more intense. That is possible, since it is the highest category and the intensity of such hurricanes may shift upwards. But then I remember reading one of the hurrican experts (if it was Maue or Landsea or someone else I don’t recall) saying that a cat.5 pretty much levels everything already, so making it more intense is not really going to change its impact.

yarpos
December 18, 2020 1:59 am

Covers all the bases I guess. If there are more “its worse than we thought” and of course a big one will eventually come statistically, so just as predicted.

Ulric Lyons
December 18, 2020 8:43 am

“Interestingly the simulated pattern of future tropical cyclone changes is quite similar to the recent observed trends, which supports the notion that global warming is already altering global extreme weather”

Interestingly recent trends are intrinsic to lower indirect solar since 1995 driving a warm AMO phase and increased El Nino conditions.

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