Clouds are an essential part of Earth’s climate system. They play a big role in weather patterns, rain, and regulating global temperatures. A recent study titled “Supersaturation and Critical Size of Cloud Condensation Nuclei in Marine Stratus Clouds,” published in Geophysical Research Letters, gives us new information about how clouds form, especially over the ocean.
What Are Cloud Condensation Nuclei (CCN) and Supersaturation?
Clouds form when moist air rises and cools. This cooling leads to supersaturation, where the air has more water vapor than it can hold. This extra water vapor condenses onto tiny particles called cloud condensation nuclei (CCN), which then grow into cloud droplets. The size and number of these CCN are crucial for determining what the clouds will be like.
Traditionally, scientists thought that only larger particles (around 60 nm in diameter) could become CCN at typical supersaturation levels (0.2%–0.3%). However, this study by Henrik Svensmark and his team shows that much smaller particles can also act as CCN if the supersaturation is higher than previously thought.
Main Findings of the Study
- Higher Supersaturation Levels: The study found that marine stratus clouds, especially those off the coast of California, often have supersaturation levels higher than 0.5%, and sometimes even up to 1%. This is much higher than what scientists used to believe and suggests that smaller particles (25-30 nm) can act as CCN in these conditions. The authors wrote, “On average, supersaturation in marine clouds is significantly higher than the conventional view of 0.2%–0.3%.”
- Smaller Critical Size of CCN: By using satellite data and scientific theories, the researchers created maps showing global supersaturation levels and the sizes of particles that can act as CCN. They found that marine clouds are more sensitive to changes in the number of small particles because of these higher supersaturation levels. This means that even smaller particles than previously thought can form cloud droplets. The study notes, “Higher supersaturation implies smaller activation size for CCN making cloud formation more sensitive to changes in aerosol nucleation.”
- Effects on Cloud Properties: Higher supersaturation levels mean that cloud formation is more dynamic and sensitive to changes in the particles that act as CCN. This can change cloud properties, like how many droplets they have and how thick they are, which affects how much sunlight they reflect and how much heat they trap. The study explains, “Due to the higher supersaturation, much smaller aerosols get activated into cloud droplets.”
How Did the Researchers Study This?
The researchers used data from different sources, including satellite observations and airplane measurements. They analyzed these data to understand the relationship between the number of CCN and supersaturation.
- Satellite Observations: They used satellite data to estimate the number of droplets in marine stratus clouds. This, along with measurements of cloud thickness and water content, helped them analyze cloud properties over the oceans.
- Airborne Measurements: Measurements from airplanes off the coast of California were crucial in discovering the higher-than-expected supersaturation levels. These measurements provided direct evidence that smaller particles could act as CCN. The authors noted, “Observations of marine stratus clouds in clean air off the Californian coast reveal a functional relationship between the number of cloud condensation nuclei (CCN) and supersaturation.”
- Simulations: The researchers used a computer model to simulate how cloud droplets form under different conditions of supersaturation and vertical movement. These simulations supported their observations, showing that smaller particles could form cloud droplets at higher supersaturations. The study states, “Independent support for such high supersaturation in the marine cloud is obtained from CCN measurements provided by the ‘Atmospheric Tomography Mission.'”
Why Is This Study Important?
This study is important because it changes our understanding of how clouds form. Clouds play a key role in Earth’s climate by reflecting sunlight and trapping heat. Small changes in cloud properties can have a big impact on weather and climate. By showing that cloud formation is more sensitive to smaller particles and higher supersaturation levels, this study helps us better understand how clouds and aerosols interact.
- Aerosol-Cloud Interactions: The study shows the complexity of how aerosols (tiny particles) and clouds interact. Understanding these interactions better is crucial for improving weather and climate predictions.
- Cloud Microphysics: The research highlights the importance of supersaturation levels in determining cloud properties. This has implications for studying and modeling different types of clouds and their roles in weather systems.
Conclusion
The study “Supersaturation and Critical Size of Cloud Condensation Nuclei in Marine Stratus Clouds” by Svensmark et al. provides new insights into how clouds form. By revealing higher-than-expected supersaturation levels and the activation of smaller CCN, this research challenges what we thought we knew and opens new doors for understanding Earth’s atmosphere. As we continue to learn more about cloud formation, studies like this are essential for understanding the complexities of our climate.
Cloud formation is a complex process influenced by many factors. This study sheds light on some of the key aspects of this process, especially in marine environments, and highlights the importance of continuous observation and research to uncover the mysteries of our planet’s atmosphere.
The study is open access and can be read here.
H/T Ken Gregory, Friends of Science
Is there a formula that determines at what height clouds form? As the moist air rises and expands to occupy a larger volume and condensation begins, at what point does gravity take over?
As air expands, it cools. In general clouds will start to form when this cooling results in a relative humidity that exceeds 100%.
Under certain circumstances, humidity can exceed 100% by a small amount.
Gravity takes over when the weight of the growing drop exceeds what can be lifted by the existing updraft.
and then you get hail?
That depends on how strong the updraft is. A weak updraft is not capable of lifting the droplets high enough for them to freeze.
Another thing to remember is that you get higher, the air gets thinner. Therefore the updraft has to be faster in order to support the same size droplet.
“Another thing to remember is that you get higher, the air gets thinner.”
hmmmm… I’ve noticed that. 🙂
…and the water also supercools before crystallising. Another out of equilibrium process they think they can model sufficiently well.
When some supercooled fluids decide to crystallise in the flask is one of the marvels of chemistry.
Some crystallographers have a sealed protein solution siting on their desk, waiting for it to crystallise. The joke is that the crystallographer can say they are running an experiment, and thus are always ‘at work’.
It’s often a dark art, but, as usual, the modelers have claimed to solve something the experimentalists can’t.
Back when I was teaching, we had a geology lab experiment that all beginning students were expected to perform. We had several electric hot plates on the bench along one wall that had petri dishes on them with thymol in them. Once the thymol melted, the students were expected to take a dish back to their seat at a lab table and observe the crystallization of the thymol with a stereo-microscope.
At the last lab session of the day, the hot plates with the petri dishes were too hot to handle, so we would just unplug them and leave them sit overnight. We would then put them away the next morning. Frequently, there would be one or two petri dishes that, while cold, still had liquid thymol in them. The slightest disturbance would cause a flash crystallization of the liquid contents of the petri dishes. That was actually more entertaining than watching the dish contents crystallize slowly. What was being observed was super-saturation of the melted thymol.
Wasn’t all this studied by Kirkby et al at CERN years ago, except that they were warned by the director of CERN that whatever they published must be “politically correct” ?
I know nothing of that- but I hope Kirby et al did the right thing and not the PC thing.
From my recollection, the CERN cloud project results were published but without commentary or conclusions to avoid any problems with the eco-nutters.
Cloud formation is obviously not yet well understood. The various AR’s say clouds are the most uncertain thing in climate ‘science’. The IPCC insists that net cloud feedback is significantly positive (warming), while there are several lines of observational evidence going back to Dessler 2010 showing it is zero or slightly negative. Covered this cloud conundrum in essay ‘Cloudy Clouds’ in ebook Blowing Smoke.
The only CMIP6 model that does NOT produce a spurious tropical troposphere hotspot is INM CM5. The Russians thought this so important that they published a paper on it, Volodin et al in Climate Dynamics at DOI 10.1007/s00382-017-3539-7. Turns out that they parameterized ocean rainfall to match ARGO. Which means their ocean cloud parameterization was more realistic than any other CMIP6 model.
So much for ‘settled climate science’.
Thanks.
Still can’t tell what the implication of smaller CCN is?
Does it imply a significant magnitude in effects?
Closer to observation or IPCC hysteria?
In my limited understanding, the text above slightly misrepresents the formation of CCN when it says that water droplets for by themselves, meaning involving only water vapour at some concentration. Every droplet has to form on something. Water vapour by itself does not constitute a cloud condensation nucleus. There are many things which serve as a starting point for a small droplet, the most common being a dust particle or something as small as a hydrogen sulphide molecule. An H2O molecule is too small to start a chain reaction leading to a droplet. That is how I understand it.
Some materials like silver iodide can cause droplets to form even when the air is not saturated – rain-making. The reason air super-saturates at all is because water vapour needs a helping hand to get started on rain-making.
There is a lot of bromide in the air from the ocean. That works, and of course the GCR’s are well known to create a trail of droplets in a saturated volume of gas – Svensmark’s postulation. In each case there is some secondary actor that initiates the the formation of a droplet hence the name CCN.
In a hurricane there are huge volumes of supersaturated air moving in concentric curtains. The reason it does not condense is because all the available particles have been extracted from the air. A small piece of hail dropping through such an air mass accumulates ice *very* rapidly because it is the only show in town.
In closing, water vapour per se is not a CCN, something not explicit in the comments.
The lower atmosphere is almost entirely an aerosol, due to combustion of fossil fuels, forest fires, etc.
Snow-covered areas turn brownish; they reflect less, absorb more, and melt faster
Even a rainfall does not “clear the air”, the way it used to.
That means there is an abundance of condensing sites, large, such as pollen, and small, such as from fuel injected engines.
Yeah, what I learned was smaller CCN’s can support water droplet condensation when the atmosphere is supersaturated.
We can assume this condition has existed for as long as the Earth has existed in its current form.
I’m not sure what the implications of this discovery might be. It’s another factor to take into account.
Changes in cloud cover, according to CERES data, can account for all the warming of the Earth over the last 25 years, so the study of clouds and how and why and when they form should now be at the front of climate science.
We have cloud data that says CO2 is not the control knob of the Earth’s temperatures. It would behoove us to find out whether this is the case or not. If cloud coverage is the control knob, then we can scrap the disastrous, destructive CO2 Net Zero insanity tomorrow because there is no need for it.
To put some simple math behind that
1) “Cloud albedo strongly influences the Earth’s energy budget, accounting for approximately half of Earth’s albedo.[1][2]” with:
Ref [1] being Hay, William W. (2016), Experimenting on a small planet: a history of scientific discoveries, a future of climate change and global warming (Second ed.). Switzerland: Springer. pp. 355–371. ISBN 978-3-319-27404-1,
and Ref [2] being Mueller, Richard; Trentmann, Jörg; Träger-Chatterjee, Christine; Posselt, Rebekka; Stöckli, Reto (2011), “The Role of the Effective Cloud Albedo for Climate Monitoring and Analysis”. Remote Sensing. 3 (11): 2305–2320.
(source: https://en.wikipedia.org/wiki/Cloud_albedo )
2) Earth receives TOA insolation of 1361 W/m^2 and Earth has an average albedo of about 0.3. Therefore, if variation in areal cloud coverage controls half of the albedo, it controls about 0.15 x 1361 = approximately 200 W/m^2 of Earth’s power input.
3) Climate scientists currently worry about Earth’s net radiative imbalance being around 0.6 W/m^2 or less as the primary driver of Holocene era climate trends (see Figure 2 of “Earth’s radiative imbalance from the Last Glacial Maximum to the present”, Baggenstos, et.al., available at https://www.pnas.org/doi/10.1073/pnas.1905447116 )
So, cloud cover variability making possible a maximum swing of 200 W/m^2 vs only 0.6 W/m^2 scientifically established to be necessary for the Holocene variability . . . yeah, that sounds good to me.
we can scrap the disastrous, destructive CO2 Net Zero insanity tomorrow because there is no need for it.
There never was, and those in charge know it. So nothing has changed
The IPCC “CO2-control-knob” horse manure likely did not reach Russian minds, certainly not STEM minds.
So, Volodin went about his analysis as usual, i. e., unhindered by “we own the faux science” dogma, and did the logical, professional thing of using objective ARGO MEASUREMENTS and, no surprise, came up with the same results as the Western objective balloon and satellite measurements.
The IPCC is careful to never mention the superior result of Volodin, because it is “heretical”
All the other, subjective graphs are politics-inspired, follow-the-faux-science horse manure, meant for scare-mongering and befuddlement of the lay people, and further enrichment of the moneyed elites, and for increasing their command/control over you, the despicable plebes.
Generally, nuclei of the appropriate size are necessary to form crystals out of a melt or saturated solution. However, there are certain bacteria that are able to inhibit the formation of ice crystals even in the presence of nuclei. Thus, in the presence of the bacteria, the phase change occurs at a temperature much lower than the stated 0 deg C for water. The release of heat thus doesn’t always occur, as predicted, at the ‘freezing point’ of water.
See my remarks about thymol above at https://wattsupwiththat.com/2024/05/26/new-paper-from-henrik-svensmark-on-supersaturation-and-cloud-condensation-nuclei/#comment-3917012
Working a little with those interested in ocean gases before they were demonized and along with rare but important examples, I have long been interested in ocean gas supersaturation. The physics is beyond me and seems counterintuitive but supersaturation percentages in water for gases with higher air concentrations are obviously much higher. Crossing the air/water boundary still seems complex at least in the ocean with widely different volume/area ratios from the tiny droplets supersaturated in air. Cloud condensation nuclei (CCN) formation must be one of much of what I don’t understand but the ocean is full of ‘nuclei.’ May be a dumb question but how much gas can a droplet contain? Interesting paper regardless.
There has been an accepted given that atmospheric gases, mainly oxygen of interest, at the thin ocean boundary must be higher but never located any satisfactory evidence. We studied August Krogh who started out studying gases but ended up as an expert in osmosis which may have seemed simpler to study at the time.
Remember, once one lightning bolt has formed, the ionised atmosphere is seeded with lots more nucleation points (charge, not surface area being the means of nucleation).
Once it gets a start, it keeps going on until the precipitation lowers the saturation level.
If colder is better, this is good news. Cloud seeding and brightening should be easier than expected.
With good enough models and seeding processes, it may even be possible to limit droughts.
Story Tip.
We all know the great work AW and others have done on exposing the woeful state of US surface stations.
Ken’s Kingdom and others in Australia exposing BoM…
Ray Sanders is now holding the UK Met’s feet to the fire and finding some real anti-science and site corruption going on.
Sites the Met have classes as “1” are being challenged, and found to be “3 or 4”
Fake sites are being exposed. Loss of Rural sites being exposed.
And the Met do not like it 😉
https://notalotofpeopleknowthat.wordpress.com/2024/05/26/met-office-creates-warming-out-of-thin-air/#comment-286579
And solely on the basis of these temp stations cluster-fvckz, the “settled climate science” morons are constructing “global average temperature” numbers upon which to con the world into trashing their industries, economies and standards of living.
One could easily be forgiven for concluding that Western societies really should be overtaken by the mongolian hordes.
We’d be too dumb to notice any difference.
My Climate Science forecast is for gray, cloudy skies with a slight chance of sunny days ahead.
Only if the Sunny Days express goes right over Trudeau
stupid question- is fog just a cloud at the ground level?
Yes. However, clouds typically form when moist air rises and then cools and are thus high above ground level unless one is in the higher mountains. Therefore most fog is produced by an atypical condition, most commonly the passage of warmer moist air over a colder body of water that cools the air and produces condensation at ground level but the sky remains clear higher up.
One of the most interesting things I have observed is the top of the Tule fogs (advection fogs) in the Sacramento Valley (CA) during the Winter. At about 2,000 feet elevation and above in the Mother Lode, it can be sunny and 70 deg F in January. In Sacramento, it may be near freezing. Looking out over the top of the Tule fog, with some locally high peaks in the Mother Lode, it looks like a grey ocean surrounding islands off the ‘shore.’
Svensmark, et al, state that “cloud formation is a complex process influenced by many factors”.
I disagree:
Cloud formation just requires adequate moisture nucleation sites, the major one being Sulfur Dioxide (SO2) aerosols, micron-sized droplets of Sulfuric Acid (H2SO4), which has a strong affinity for moisture, often being used as a drying agent.
Current global “Clean Air” and “Net-Zero” efforts are decreasing the amount of SO2 aerosols in our atmosphere, thus reducing the number of available SO2 aerosol nucleation sites, decreasing cloud formation, and causing temperatures to rise.
This increases evaporation, and the atmosphere becomes supersaturated with moisture, releasing it in apparently random torrents of rain around the world. These torrents have been known as “Atmospheric Rivers” since the 1990’s, and have been observed around the world for centuries, being caused by volcanic-induced El Ninos, or extended periods of no volcanic activity.
Rising temperatures also cause more chaotic weather events, such as tornadoes, droughts, and heat waves, in addition to the flooding.
The cure for the above is obvious, simply halt ALL activities that remove SO2 aerosols from our atmosphere.
(This assumes that we have not already removed too much from our atmosphere. In that case, some geo-engineering will be required to lower temperatures).
Yes, Burl, the increased use of natural gas (and to a lesser extent solar and wind power) rather than coal has decreased the SO2 levels and thus decreased the CCN’s that create clouds that lower global temperatures. Some AGW promoters claim the reversal of the warming trend seen in the 1950’s and ’60’s was due to the high percentage of coal use at that time. The warming that recurred later after natural gas use increased was just a continuation of the more long-term warming trend secondary to rising CO2.
If that’s true, we should expect a cooling trend from all of the new coal-powered plants (especially in China and India). Perhaps this explains the desperation by the climate activists in the past few years to act quickly so that they can take credit for the cooling when it happens.
Neo Conscious:
My intent was to warn of the dangers of reducing SO2 aerosol nucleation sites in our atmosphere. Both on-going “Clean Air” efforts to reduce Industrial SO2 aerosol emissions, and the abandoning of the burning of fossil fuels (which also produce SO2 aerosols) are reducing nucleation sites. The mandate to use low-sulfur fuels for maritime shipping has also reduced nucleation sites, and this is apparent in the reduced cloudiness in the shipping lanes.
Hopefully, your expected cooling trend will materialize to offset the warming, but I am not holding my breath.
How does SO2 explain the ups and downs of the U.S. surface temperature chart (Hansen 1999)?
There was no Net Zero or Clean Air Act from 1910 to 1930’s, yet the temperatues climbed at the same magnitude as they did from 1980 to the present, and reached the same level of warmth.
Something other than SO2 was driving this warming trend.
Tom Abbott:
SO2 does not drive a warming trend.
DECREASES in the amount of SO2 aerosol pollution causes warming.
For example, the warming of the early 1930’s.was caused by a 13 million ton reduction in SO2 aerosol emissions, because of reduced industrial activity during the depression.
All of the other increases can be correlated with decreased SO2 aerosol levels, mostly due to decreased industrial activity during American business recessions.
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“For example, the warming of the early 1930’s.was caused by a 13 million ton reduction in SO2 aerosol emissions, because of reduced industrial activity during the depression.”
The temperatures increased during ths time span from the 1910’s to the 1930’s. There was no depression in 1910.
Then you need to explain the cooling that came after the 1930’s, and then you have to explain the warming that began during the 1980’s.
All this from SO2? I don’t see the connection.
Tom Abbott:
“There was no depression in 1910”
No, but there was a 24 month recession that lasted from Jan 1910 to Jan 1912, and temperatures ALWAYS rise during a recession.
There were also recessions in 1913, 1918, 1923, 1926, and Aug 1929, which lasted until March 1933, causing the depression..
The cooling that came after the 1930’s was due to the rise in industrial SO2 aerosol emissions, which grew from ~50 million tons in 1941 to 139 million tons in 1980.
The warming that began in the 1980’s was due to Clean Air legislation enacted in the 1970’s to reduce industrial SO2 aerosol emissions, because of Acid Rain and health concerns. They fell from 139 million tons in 1980, to 72 million tons in 2021, a reduction of 67 million tons, which HAS to have been the cause of our modern warming, due to the massive decrease in atmospheric SO2 aerosol pollution.
(I have explained this to you, before. You appear to be having a problem with your short-term memory!).
Hmmm . . . more rainfall with fewer clouds . . . i keep trying to imagine that scenario but keep coming up with butkus.
Toldyouso:
Fewer clouds=increased warming=increased evaporation=atmospheric supersatuation=random torrents of rain with no clouds, from atmospheric rivers.
These discrete rivers are easily seen in satellite images of atmospheric moisture levels.
Exactly, they are revealed by—guess what—visible clouds. Amazing, isn’t it?
Please provide a science-based reference to support that statement.
In a timely coincidence, a new WUWT article (https://wattsupwiththat.com/2024/05/27/it-gets-rainier/ authored by Willis Eschenbach) refutes your above assertion:
“Well, that’s interesting. Overall, despite endless hype about increasing floods, there’s no significant trend in rainfall”, referring to a graph he presents of global monthly rainfall based on data from the Copernicus global rainfall dataset for the interval 1980 to 2020 . . . see a copy of that graph attached below
There were five major volcanic eruptions (VEI rating of 5 or higher) during this 40 year timespan:
— Mount St. Helens (VEI 5) in May 1980
— El Chichón (VEI 5) in April 1982
— Mount Pinatubo (VEI 6) in June 1991
— Mount Hudson (VEI 5) in August 1991
— Puyehue-Cordón Caulle (VEI 5) in June 2011
There is no consistent correlation of these volcanoes (or the intervals between their occurrences) with the measured variations in global monthly rainfall.
Say what??? . . . I am of the firm belief that rainfall removes SO2 aerosols (being identified as CCN) from the atmosphere . . . so that “simple solution” will certainly have some unintended consequences, assuming we could do so in the first place. 😳
Toldyouso:
Global Industrial SO2 aerosol levels have fallen from 139 million tons in 1980, to 73 million tons in 2022, leaving 66 million tons of SO2 aerosol pollution in our atmosphere, then, and even less by now. This decrease in atmospheric SO2 aerosol pollution has caused our temperatures to rise, because of the increasing intensity of the solar radiation striking the Earth’s surface due to the cleaner air..
With fewer SO2 aerosol moisture nucleation sites available, cloud cover is deceasing, and as a result, further warming is occurring and we are experiencing drought conditions around the world, and the random atmospheric rivers associated with them.
In no way am I saying that rainfall episodes have increased, although periods of .intense rainfall probably have.
.
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The graph and text I presented from the cited Willis Eschenbach article deals with facts that run counter to your pronouncements and asserted probabilities.
ToldYouSo:
The rainfall graph from Willis shows a strong downward slope at the end, supporting my comments that cloud formation, and hence, rainfall, is decreasing.
That’s commonly known as “cherry picking” the data to support one’s argument.
Carry on.
ToldYouSo;
It is also known as supportive data that confirms a hypothesis.
What are the dominant particles in our atmosphere in the typical (60nm) range that contribute to Cloud Condensation Nuclei and where do they come from?
What is the makeup and source of these smaller CCN (25-30 nm) that are perhaps more important than previously realized?
There are reports that the solar variation from solar cycles can have an impact on CCN’s, and if so, does this have a different impact on these smaller CCN’s than ones in the typical range?
Just a little something to add to the mix:
https://www.mining.com/common-mineral-plays-key-role-in-cloud-formation/.
interesting chemistry.
This is a very interesting observation that fits nicely with some work I did that was published in 2021. We found that liquid cloud water droplets behaved as if they were coated with a thin shell that was structurally the same as ice. This could explain the extremely anomalous solubility of noble gases in fog or cloud droplets. We saw a very large suppression of solubility for Xe, with lesser effects for Kr and Ar. On top of that, He solubility was slightly enhanced. There was measurable isotopic fractionation of the heavy noble gases as well. I suspect that the Kelvin equation part of Kohler theory might break down for very small particle sizes because of three significant factors: the dual structural nature of liquid water, surface tension and Archimedes’ Principle.
Hall, C.M., Castro, M.C., Scholl, M.A., Amalberti, J. and Gingerich, S.B., 2021. Anomalous noble gas solubility in liquid cloud water: Possible implications for noble gas temperatures and cloud physics. Water Resources Research, 57(12), p.e2020WR029306.
From the first paragraph under the above article’s sub-heading Main Findings of the Study:
“This is much higher than what scientists used to believe and suggests that . . .”
Now, who was it that originated that cute phrase some 25+ years ago: “The science about climate change is settled.”?
Well, here’s one meteorologist’s (Glenn “Hurricane” Schwartz’s) account:
“Then, it was determined that the satellites were wrong — not the ground observations! That was enough for me. I also got to interview Dr. Jerry Mahlman, head of the prestigious Geophysical Fluid Dynamics Laboratory in Princeton. When I asked him about the “debate” he said, “We stopped arguing about that years ago. The science is settled.”
“That was in 1996! Yet the deniers continued for another 20-plus years, and a lot of meteorologists (especially those on TV) were in that group. Today, the great majority of climate scientists and meteorologists have accepted the science.”
— source: https://www.anspblog.org/climate-change-and-me/
Poor Dr. Mahlman, assuming Schwartz’s account is accurate. . . the Internet never forgets!