Claim: Clouds Less Climate-Sensitive than Assumed Airborne campaign solves parts of the riddle of …
Claim: Clouds Less Climate-Sensitive than Assumed
Airborne campaign solves parts of the riddle of clouds
UNIVERSITY OF HAMBURG
CREDIT: MPI-M
In a major field campaign in 2020, Dr. Raphaela Vogel who is now at Universität Hamburg’s Center for Earth System Research and Sustainability (CEN) and an international team from the Laboratoire de Météorologie Dynamique in Paris and the Max Planck Institute for Meteorology in Hamburg analyzed observational data they and others collected in fields of cumulus clouds near the Atlantic island of Barbados. Their analysis revealed that these clouds’ contribution to climate warming has to be reassessed.
“Trade-wind clouds influence the climate system around the globe, but the data demonstrate behavior differently than previously assumed. Consequently, an extreme rise in Earth’s temperatures is less likely than previously thought,” says Vogel, an atmospheric scientist. “Though this aspect is very important for more accurately projecting future climate scenarios, it definitely doesn’t mean we can back off on climate protection.”
To date, many climate models have simulated a major reduction in trade-wind clouds, which would mean much of their cooling function would be lost and the atmosphere would consequently warm even more. The new observational data shows that this isn’t likely to occur.
What is certain is that, as global warming progresses, more water on the ocean’s surface evaporates and the moisture near the base of trade-wind clouds increases. In contrast, the air masses in the upper part of the clouds are very dry and only become slightly moister. This produces a substantial difference in moisture above and below. In the atmosphere, this is dispelled when the air masses mix. The previous hypothesis: drier air is transported downward, causing the cloud droplets to evaporate more rapidly and making it more likely that the clouds will dissipate.
The observational data from Barbados now offers the first robust quantification as to how pronounced the vertical mixing actually is, and how this affects moisture and cloud cover as a whole. As such, it is the first data to shed light on a process that is essential to understanding climate change. In brief: more intensive mixing does not make the lower layers drier or make the clouds dissipate. Rather, the data shows that the cloud cover actually increases with increasing vertical mixing.
“That’s good news, because it means that trade-wind clouds are far less sensitive to global warming than has long been assumed,” says Vogel. “With our new observations and findings, we can now directly test how realistically climate models portray the occurrence of trade-wind clouds. In this regard, a new generation of high-resolution climate models that can simulate the dynamics of clouds around the globe down to scales of one kilometer are particularly promising. Thanks to them, future projections will be more accurate and reliable.”
The month-long field campaign EUREC4A (2020) was designed by the team members around extended flights with two research aircraft, which were equipped with different instruments and operated at different altitudes, and shipboard measurements from the R/V Meteor — A German research vessel managed by the University of Hamburg. One plane was used to drop hundreds of atmospheric probes from an altitude of nine kilometers. As they fell, the probes gathered atmospheric data on the temperature, moisture, pressure and wind. The other plane surveyed clouds at their base, at an altitude of 800 meters, while the ship performed surface-based measurements. The result: an unprecedented database that will help to understand the unclear role of clouds in the climate system – and to more accurately predict their role in future climate change.
Whether clouds have a cooling or warming effect depends on how high they are. With a maximum altitude of two to three kilometers, the trade-wind clouds examined here are comparatively low, reflect sunlight, and cool the atmosphere in the process. In contrast, higher clouds amplify the greenhouse effect, warming the climate.
Publication: Vogel R, Albright AL, Vial J, George G, Stevens B, Bony S (2022): ; Nature, DOI: 10.1038/s41586-022-05364-y
Nature Research Briefing:
JOURNAL
Nature
DOI
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Strong cloud-circulation coupling explains weak trade cumulus feedback
ARTICLE PUBLICATION DATE
30-Nov-2022
COI STATEMENT
No COI
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December 4, 2022 2:09 pm
“but the data demonstrate behavior differently than previously assumed”
I should think if it’s science there should be no assumptions.
December 4, 2022 2:14 pm
Well, that is progress, but what they haven’t yet realised is that changes in vertical mixing will have equal and opposite effects in rising and falling air so the net effect overall is zero. Analysing vertical mixing is therefore pretty pointless. Cloud formation in rising air is matched by cloud dissipation elsewhere in falling air.
To get a change in average global temperature it is necessary to change planetary albedo and that has to be effected by a change in average total cloud cover. That involves horizontal mixing.
The most likely cause of that is a change in the waviness of jet stream tracks because waviness controls the length of the lines of air mass mixing around the globe. Short lived clouds do arise from vertical mixing but long lived cloudiness arises from horizontal mixing where there is contact between air masses of different characteristics.
Reply to
December 4, 2022 2:19 pm
Little by little, step by step, appearing cracks are growing wider.
December 4, 2022 2:18 pm
This work is causing all kinds of problems by eliminating high ECS scenarios. It is obvious it is being selectively dismissed by those who are rooting for warming. To some, the optimal warming is in the range 1.5 – <2C so they can say “see, I told you so”, and remaining below 2C so they can say “see, look how we solved the problem.” It is a very narrow range they are shooting for to justify their existence. Their legacy is at stake, and any suggestion that warming might be in the far low end of projection, regardless of intervention, is seriously problematic.
Reply to
December 4, 2022 2:44 pm
It should be noted that the basis for total societal transformation is the precautionary principle due to extreme high end of ECS conjecture. If such scenarios are eliminated it impacts all economic calculus. IMO it is good news to eliminate unphysical assumptions, so we can get back to a sensible debate about environmental management priorities. Once the extreme ECS scenario boogeyman is gone it’s all hands on deck to restore credibility to environmental science. For I must admit that for the past while has been an embarrassment to be an environmental practitioner, whereupon any funding application and public communication pieces must make a link to global warming. In the process this has become a hindrance to gaining trust and respect in the communities in which we serve, and has been net damaging to environmental amelioration. In fact, most of our budgets have now been displaced and put into green tech venture capital, tech subsidies, and litigation.
Reply to
December 4, 2022 3:17 pm
The problem is that all environmental science has been tainted by the AGWF for the last thirty years and has to be re-done from the start.
Reply to
December 4, 2022 3:43 pm
That is not the case. The fundamentals of my sector of soils and watershed management have not changed since the time of F D Roosevelt. It is not glamorous, but the solutions to ecosystem desiccation and associated drought and flood hazards are well known. It is the bureaucrats who must be retrained, and perhaps students who graduated since about 2004. Additionally, journalists and politicians who have learned that any and all environmental hazards are to be associated with AGW, when in fact the issues are far more straightforward. The engineers know this, as they look at IDF curves and note hardly any change, as they cringe at infrastructure maintenance budgets and larger stormwater needs. It is a deficit in investment and education where it is needed, but the science is well understood. An overhaul of insurance and regional planning may be required, in addition to realtors unaware of the hazards to which their clients are being exposed (irrespective of climate changes). Ecologists, hydrologists, and engineers know exactly what’s up.
Reply to
December 4, 2022 4:03 pm
The average global temperature will rise a lot more before the snow starts accumulating. I expect no levelling in trend before 2200.
I doubt we will see ice accumulating on the large land masses again before the end of this century.
It is encouraging to observe Iceland is already accumulating ice again. Its southern tip is 63N.
The snowline on the east and west coasts of North America should by descending now or soon will be.
December 4, 2022 2:34 pm
> The month-long field campaign …One plane was used to drop hundreds of atmospheric probes from an altitude of nine kilometers. …The other plane surveyed clouds at their base, at an altitude of 800 meters, while the ship performed surface-based measurements. The result: an unprecedented database…
So… ONE MONTH of sparse data refutes decades of settled science.
I thought i was beyond emotions concerning climate “science” but I wish to donate my share of the multiple Nobel’s coming our way to endowing WUWT with a permanent funding stream.
December 4, 2022 2:41 pm
This is more of an admission that GCMs do not model clouds and require parameterization to make up that lack. Yet another reason why computer models are mostly useless.
Reply to
December 4, 2022 3:19 pm
If they’d actually get down to the fact that the GCMs don’t even model climate at all and admit that the temperature at ground level doesn’t represent jack shit to begin with… THEN we can start doing science.
Gravity defines the amount of energy per measured volume and the temperature of that air means exceptionally little both locally and globally for “climate”
December 4, 2022 3:13 pm
the clouds aren’t in the level of atmosphere they claim to be representing through their fraud
December 4, 2022 3:55 pm
As such, it is the first data to shed light on a process that is essential to understanding climate change.
And the science was settled 100 years ago.
It amazes me that no one in academia has attempted to understand convective instability over oceans by actually quantifying what happens.
On the other hand if you lack the understanding in physics to believe that there is a “greenhouse effect” controlling earths energy balance and back radiation from cold to hot exists then there is not much hope.
Precession has created “global warming” 4 times in the last 500k years that ended interglacials. Why wouldn’t “global warming” do the same thing now.