Unexplainable

Cloud atlas

29 min
Feb 2, 20263 months ago
Listen to Episode
Summary

This episode explores the science of clouds and why they remain one of the biggest unknowns in climate modeling. Despite their ubiquity and critical importance to weather, rainfall, and temperature regulation, scientists struggle to predict cloud behavior due to the complexity of scaling from molecular to planetary levels, and lack historical data on pre-industrial cloud patterns.

Insights
  • Clouds represent a critical gap in climate science: while we understand molecular-scale cloud formation and planetary-scale distribution, the middle-scale mechanics that connect these remain poorly understood, limiting predictive capability
  • Cloud behavior exhibits emergent properties that cannot be predicted from individual droplet behavior, making them fundamentally difficult to model despite their massive real-world impact on weather and climate
  • Clouds present a paradoxical climate wildcard: low-altitude clouds reflect heat and cool the planet, while high-altitude clouds trap heat like a blanket, and scientists cannot reliably predict which type will dominate as climate changes
  • Historical cloud data is nearly non-existent, forcing researchers to rely on indirect sources like ship logs, art, and literature to understand pre-industrial cloud patterns and establish climate baselines
  • The chaotic nature of atmospheric systems means tiny microscopic changes in cloud formation can cascade into massive effects at continental scales, making long-term weather and climate prediction inherently limited
Trends
Digitization of historical maritime records as a climate research methodology to reconstruct pre-industrial atmospheric conditionsInterdisciplinary climate research incorporating art history and cultural records to fill gaps in scientific dataRecognition of clouds as the largest source of uncertainty in climate models, driving increased research funding and focusGrowing appreciation for emergent phenomena in complex systems as a framework for understanding atmospheric behaviorShift toward acknowledging fundamental limits in predictive climate modeling while emphasizing need for continued research investmentIntegration of chaos theory and complexity science into climate and weather prediction modelsDevelopment of specialized aircraft and instrumentation for direct cloud observation and measurementIncreased focus on understanding cloud-aerosol interactions and human influence on cloud formation through pollution and industrial emissions
Topics
Cloud Formation and MicrophysicsClimate Change and Cloud Feedback MechanismsAtmospheric Chaos and Predictability LimitsWeather Prediction and ForecastingAerosol-Cloud InteractionsHigh-Altitude vs Low-Altitude Cloud EffectsCumulonimbus Storm CloudsCloud Seeding and Artificial Cloud ModificationHistorical Climate ReconstructionEmergent Phenomena in Complex SystemsAtmospheric Water CycleGreenhouse Gas Emissions and Atmospheric CompositionMaritime Climate Records and Ship LogsCloud Appreciation and Cultural PerspectivesFaraday Cage Physics in Aircraft
Companies
Argonne National Laboratory
Atmospheric scientist Scott Collis works here and provided expert commentary on cloud formation and aerosol particles.
Cornell University
Climate physicist Angie Pendergrass is based here and discussed the complexity of scaling cloud models from droplets ...
Vox Media
Parent company of the Unexplainable podcast and Vox science reporting; hosts South by Southwest podcast events.
People
Tom Warner
Retired Air Force pilot who flew a 1949 vintage aircraft into thunderstorms for 30+ years to study severe weather phe...
Scott Collis
Atmospheric scientist at Argonne National Laboratory who explained aerosol particles, cloud formation, and cloud feed...
Angie Pendergrass
Climate physicist at Cornell University who discussed the complexity of modeling cloud behavior using double pendulum...
Gavin Predder
Founder of the Cloud Appreciation Society with 55,000+ members; discussed cultural and artistic depictions of clouds ...
Umair Irfan
Vox science reporter who co-reported the episode and conducted interviews with cloud scientists.
Noah Hassenfeld
Host of Unexplainable podcast who guided the episode narrative and interviewed cloud experts.
Christian Ayala
Sound designer for Unexplainable who created audio representations of clouds, including lava bubble sounds for cloud ...
Edvard Munch
Norwegian painter whose work 'The Scream' may depict historical cloud phenomena from Krakatoa eruption or nacreous cl...
John Constable
19th century landscape painter who stated 'the sky is the chief organ of sentiment in a landscape,' influencing cloud...
Quotes
"To me, that's the ultimate cloud, the cumulonimbus, the thunderstorm. It's capable of so much power and so much beauty at the same time."
Tom WarnerEarly in episode
"Clouds are where the rubber meets the road in terms of weather. You know, things like rainfall, things like temperature, wind, a lot of that is mediated and governed by cloud formation."
Scott CollisMid-episode
"There's more water in the air above the Amazon than there is in the Amazon River."
Umair IrfanMid-episode
"Clouds are almost always the largest source of uncertainty in those models. So where could this cloud uncertainty take us? Well, it can go in two directions."
Umair IrfanLate episode
"We don't live beneath the sky we live within it and the sky is an ocean that we inhabit we just happen to live on the bed of that ocean."
Gavin PredderClosing segment
Full Transcript
I got in the water in the very early morning before the sun had risen, and the water was pitch black. I started swimming, and I felt the water hollowing out around me, and felt like something really big was swimming below. I'm Phoebe Judge, and this is Love, a show about the surprising things that love can make us do. More than 100 episodes, available now on This Is Love. Hi, I'm Christian Ayala, and I'm the sound designer for Unexplainable. This episode is one of the first ones that I worked on when I joined the team. Imagine showing up to a new job and someone asking you to figure out what a cloud sounds like. And not just a cloud, lots of clouds. Fluffy clouds, stormy clouds, all kinds of clouds. People kept comparing the clouds to the ocean, so I added the sound of waves. But it didn't quite have the right texture. So after some thinking, I settled on adding some lava bubbles to sell the slow-moving nature of clouds. Look out for this while you listen to the episode. Enjoy! I had flown many different aircraft and planes for the Air Force, but never had the opportunity to fly an aircraft that's kind of in that World War II era, you know, 1949 vintage. Big old propeller, big old radial engine on the front. Once the storm started to form, we would get notified that the storms were starting to build in this area to get ready. And so we'd prep the aircraft. And when it was time to launch, then we'd fire it up and then take off. And then you kind of look ahead and see this huge towering cumulonimbus ahead of you. I mean, to me, that's the ultimate cloud, the cumulonimbus, the thunderstorm. It's capable of so much power and so much beauty at the same time. And it can boil with the updraft. It just looks like it's alive. You briefly ask yourself, I can't believe I'm going to go fly through this thing. That is no place for an aircraft to fly. But this aircraft was modified. It was capable. It did it for over 30 years. So to me, it was not about the adrenaline. It was about getting the opportunity to witness the power, the beauty, the strength of severe weather from inside a thunderstorm. And not many people have had that opportunity. We would aim right for it. It would be sunny and calm on the outside. And as soon as you hit that wall, the aircraft would start to rise on its own. We could keep climbing at 2,000 feet per minute. This is when you would really find out if you didn't have your straps tightened down. Lots of rain and hail, and that was one thing that was just remarkable to me, was just how noisy it was, how loud the hail was when you got into the hail shaft. And as charge builds up on the aircraft, it starts creating what we call St. Elmo's fire from the communication antenna. And so you start hearing this buzzing sound over the radio, and it increases its intensity and its frequency the more charged it builds up. And sure enough, bam, there'd be a bright flash, and when it attaches to the pillar, that plasma flows right over you. It doesn't get inside the aircraft because the aircraft's metal and it acts like a Faraday cage. cage and it usually didn't do any damage except for just melting a little bit of metal on the trailing edge of the of the tail or wing or put a little pit on the propeller so we'd continue out the the forward flank of the the storm and eventually break out of the storm get out of the storm assess how the engine is doing and then we'd set up and do 180 degree turn and go back and can do it again. It's unexplainable. I'm Noah Hassenfeld, and I'm here with Umair Irfan, Vox science reporter. And obviously, my first question after listening to that is, why is this guy flying an old tiny plane straight into a thunderstorm? Well, it turns out that even though clouds are ubiquitous and found everywhere on Earth, there's still a lot we don't know about them. Sometimes the best way to actually understand what's going on is to go straight into the middle of them. So I decided to start talking to a bunch of cloud scientists about this. And, well, one of the first things you learn talking to cloud scientists is they really love clouds. It is amazing how much science you can do just by looking at clouds. I love deep convective clouds. Those are the really puffy and tall and juicy clouds that happen all the time in the tropics. The asperitas cloud, it looks like crazy waves, as if you're beneath the sea snorkeling and you're looking up on a really rough and turbulent day. Mammatus is this droopy, undular kind of cloud. And when you get a sunset and those warm red colors of the sunset reflect on the bottom of a martyr's cloud, it looks like looking into the mouth of a giant. Clouds are where the rubber meets the road in terms of weather. You know, things like rainfall, things like temperature, wind, a lot of that is mediated and governed by cloud formation, where the clouds are and how quickly they move. So understanding them is to fill in a crucial blank with whether we have enough water available to grow crops or if we lose clouds in a given area, will that cause heat to accumulate in that area? So a lot of our real world interactions, a lot of the things that we do day to day are affected by clouds in really profound ways. Okay, so clouds are really important. They impact crops and rainfall and temperature, but are they unexplainable? Like what do we still not know about them? Well, it's really hard to anticipate them. Because they are so important, we really want to be able to get ahead of them. And right now, there's still a lot that we're still trying to figure out. At the molecular scale, we understand basically how cloud particles form. And then at the overall planetary scale, we kind of understand how clouds spread over continents and over the oceans. But connecting those in the middle, that's really difficult. And without being able to connect those dots there, it's really hard to predict how clouds are going to form and the effects that they're going to have on us. Okay so we got this small understanding this very large understanding We sort of missing the connective tissue there Let start small What exactly is a cloud Like what the stuff of a cloud It's pretty simple. You know, it's just water vapor condensing around a tiny particle. Tiny, tiny little particles we call aerosols. I talked to Scott Collis, who's this atmospheric scientist at Argonne National Laboratory. Aerosols are about one millionth of one meter in diameter. So these things are absolutely tiny, and they act as a surface that water can condense onto and make droplets. So it can be a piece of dust. It can be salt spray from the ocean. It can be pollen. It can even be pollution. And it can be synthetic chemicals that people deliberately try to seed clouds with. That's interesting because I would have thought of a cloud as a gas. And you're basically telling me that a cloud is actually a mixture of solids and liquids. Like solids at the core and liquids kind of coalescing around those small solids. Right. That's really weird. I mean, if you think about it, if you look up at a cloud, they look almost weightless. Yeah. But if you were to imagine, say, a cloud that's, you know, a kilometer on each side, like, say, a cubic cloud that's, like, one kilometer on each side, that's about a million pounds of water right there. Huh. You know, we're talking, you know, ponds and lakes worth of water directly above your head, and the very low density of it helps keep it afloat in the air. I just am kind of astounded at the fact, like, I get why a bunch of gas could stay above us and not fall down. But if you're telling me that there's a bunch of solids and liquids in the sky that are the amount of water as a pond and it is not falling on me all the time, like, how? I mean, it's the amount of water even as giant rivers. Like, there's more water in the air above the Amazon than there is in the Amazon River. What? Yeah. It's a tremendous volume of water. You know, like every tree in the rainforest can move about a bathtub's worth of water into the air every day. And they effectively help generate about half of the rainfall in the rainforest. So the trees are kind of watering themselves. How does the water, like, stay up there? Think about like a spray bottle, right? Like if you've ever used like a mister, that water doesn't necessarily fall out of the air. Now, if you could make those particles that come out of a mist or even smaller, they can stay suspended in the air for a very long time. But, you know, we can have those ingredients and still not get clouds. You know, you can have dust in the air and still have it where the atmospheric conditions won't lead to cloud formation. And it's really hard to tell exactly what that is because it can change from moment to moment from place to place. Okay, so clouds are made up of tiny bits of water that surround particles. And if being able to predict how they move and form is so important, how do scientists go from this kind of small-scale understanding to larger-scale questions like predictions? Well, I talked to the scientist about just that. You know, this is a scientist named Angie Pendergrass. She's a climate physicist at Cornell University. And she told me that the moment you start talking about more than one droplet, it gets really complicated really quickly. There's just these hard limits to what it is that you can say, especially about the specifics of how things are going to change in the future. Angie describes these as, you know, billions of droplets moving together, kind of like a double pendulum. So if you have a pendulum hanging from another pendulum, and you start spinning one of them, you stop being able to predict what it's going to do. You've got these layers and layers of complexity that keep building up. And you can't know what it's going to do because small differences grow really quickly and dominate the system. So when you have these layers of complexity building on each other, it becomes harder and harder to model and predict what's going to happen next. When you have a really small effect, it grows. So then these tiny, subtle changes that happen at the microscopic level suddenly become really, really difficult to scale up. And they have huge effects as they ripple out from the microscopic level to meters and kilometers and then over entire continents. The atmosphere is chaotic. And when you make one tiny change, that can grow exponentially and change everything. So you're saying basically we can't necessarily predict what kind of effect pumping a certain gas into the atmosphere in one place might have on rainfall or weather in a different place? It's really difficult. And right now it's beyond a lot of our capabilities. I mean, I'll give you an example. You know, think about the boundaries of a cloud. So like when you're underneath a cloud and you see its bottom, it looks pretty solid and it looks pretty flat a lot of times. But really, it's a lot more complicated than it looks. You know, it's not as though there's a sudden line where you go from cloud to not cloud. You know, the atmosphere is filled with water vapor. And so it's this constant churn of evaporation, condensation, movement, freezing, thawing, all happening at the boundaries and within these clouds. It's not quite always clear what even you mean by a cloud. And it's not always what it looks like it might be. I wonder if this is an appropriate analogy, but it almost makes me think of like a wave in an ocean. thinking of a wave as like a thing, but it's almost the rest of the ocean maybe coming into a certain shape, but there's not necessarily a moment where the wave becomes the rest of the ocean. That's right. You know, scientists kind of describe these things as emergent phenomenon. And this is this idea that the whole is greater than the sum of its parts or behaves in a different way. So if you were to look at an individual water droplet, you would expect some very predictable behaviors. you know, how it would roll or how it would move around in space if it was like a suspended aerosol. But when they're all aggregated together in clouds, those properties begin to shift and change. Then they begin to behave as an aggregate. Clouds then move together. They fuse and they create layers in the sky or they form columns where they move up and down or they condense and that water then precipitates out of the sky as rain and snow. So it has all these other properties that you wouldn't necessarily be able to extrapolate from just its constituent parts. And that's why you have to look at clouds both at a very tiny scale, but then also at this massive scale over kilometers and even over continents to fully grasp the influence that they're having on the planet. And clouds you know while they have important effects in the near term over the course of days and weeks in our lives they also have an even bigger effect over the long term And that where the picture gets even more complicated particularly if you concerned about climate change Clouds might mitigate climate change, but they also have the potential to make it worse. We just don't really know which outcome we're going to get. That's after the break. Hey, everybody, Estet Herndon here. I wanted to let you know that Vox Media is returning to South by Southwest in Austin for live tapings of your favorite podcast. Join us from March 13th through March 15th for live tapings of Pivot, Teffy Talks, Professor G's Markets, Where Should We Begin with Esther Perel, and the special live taping of Today Explained, hosted by yours truly. The Vox Media podcast stage will also feature sessions from Brene Brown and Adam Grant, Marcus Brownlee, Keith Lee, Vivian Tu, Robin Arzon, and more. Visit voxmedia.com slash South by Southwest to pre-register and get a special discount on your South by Southwest innovation badge. That's voxmedia.com slash South by Southwest. Hope to see you there. Popular pie plant pictured here. All right, Wednesday morning, cloudy with a chance of unexplainable. Umair, we're back. In the first half, you were talking about how clouds are this sort of hard to explain emergent phenomenon. I mean, we know what they are on a very, very granular level, but it's very hard to really explain how they move and change and behave. And you left off on this note of how difficult it is to predict the future and what impact that could have on climate change. So what are we talking about here? Like, what is the potential impact of clouds on climate change? So there's a lot of far-reaching effects that are going to change depending on how the clouds change as the climate warms up. You know, if you look at climate models, one of the biggest sources of uncertainty is what humans will do, whether we will actually get our act together and curb greenhouse gas emissions or just keep doing what we're doing. But after that, clouds are almost always the largest source of uncertainty in those models. So where could this cloud uncertainty take us? Well, it can go in two directions. You know, you can see clouds that make climate change worse and enhance warming, or you can see clouds that sort of offset it and mitigate some of those effects. Oh, so clouds could actually, like, help us out on global warming? That's right. Scott Collis, the atmospheric scientist we heard from earlier, explained this pretty well. So the basic way our climate works and climate change works is visible light comes in, heats the surface of the planet, and some of that radiation gets radiated back to space. Now, low clouds that sit very close to the surface of the Earth and look very white and fluffy, that are mainly made up of liquid water, they do a really good job of reflecting that incoming solar radiation back out into space. Okay, so the low-altitude clouds might be like, I don't know, wearing white on a hot day in the summer, like keeping the heat out, reflecting it? Right. On the other hand, when you have some of the more high-altitude clouds, you know, above 30,000, 40,000 feet in the Earth's atmosphere are mainly made of ice, And they can actually appear to be kind of translucent. They let some of that sunlight through, but they're very effective at blocking the outgoing infrared radiation. So they act more like a blanket. So you're saying more high-altitude clouds, more heat on the planet, right? Yeah. And I guess the issue is here that we don't really know on a large scale whether we're going to get more of these blanket clouds or more of these cooling clouds? It could quite easily go either way. It can go both ways at the same time. You know, we've only really been measuring clouds and observing them scientifically in an era where we've been also modifying them extensively. Like, we've been doing this since the Industrial Revolution when humans have been pumping greenhouse gases into the air as well as pollution. We don't have a good sense of what clouds were like before humans started drastically interfering in the atmosphere. And that's because we don't really have a good record of clouds. There's no fossil record. We have ice cores that we can use to sample the atmosphere from decades, centuries, and millennia ago. We have tree rings that we can use to look at rainfall patterns. We can look at the geological record. But clouds themselves, they have barely a footprint. Right. And so we don't really know what they looked like and how they behaved before we started spewing carbon dioxide into the atmosphere before we started emitting particles of soot and sulfur from our industrial facilities. It's almost like if scientists are trying to predict how clouds will change over time and how that'll impact climate change, they don't really have a before picture. Exactly. And that makes it really hard to get a sense of what we're doing to the planet now. We don't really have something to compare it to. We've only seen it under our influence. And the best records we have to go on are just what people told us back in the past. For instance, sailors and navigators for a long time keep very accurate track of weather because, you know, weather and wind is very important for sailing. And so now scientists are really trying to delve back into old handwritten records, especially from ship's logs, to try to understand pre-industrial cloudiness. We have maritime shipping logs going back centuries that some researchers are working on digitizing so they can actually get a sample of what clouds were like over the ocean hundreds of years ago. You know, like even sailors' legends about how they look for certain types of clouds as heralds of bad weather or good weather. Red sky in morning, sailors take warning, red sky at night, sailors delight. Exactly. And, you know, there's truth to that. You're really looking for those high cirrus clouds, usually generated, they're created by thunderstorms. When a thunderstorm happens, the vertical winds in that storm push up water vapor and cloud droplets and ice. So if you see that cirrus cloud coming to you in the morning, you know you've probably got a storm coming at you. Another thing that some scientists have suggested we should look at is art and literature. What do you mean? Like how people wrote about clouds? Well, exactly. They have been rich metaphors and rich inspiration for poets and artists throughout the ages This is Gavin Predder He is the founder of the Cloud Appreciation Society a group with more than 55 members across the world The Cloud Appreciation Society. Oh yeah, there's a lot to appreciate about clouds. And one thing that he built my appreciation for is just how profoundly clouds have influenced art and literature and culture. You can see carvings on stones in Mexico showing cumulonimbus storm clouds with recognizable features to them, you know, thousands of years old. Like, you know, how were clouds depicted in paintings from centuries ago? Does that provide a useful signal? You know, zoom right forward to the romantics of the 19th century, and you have landscape painters like John Constable said that the sky is the chief organ of sentiment in a landscape. Have you heard of that painting, The Scream, by Edvard Munch? Yeah. The Norwegian painter? Yeah, I love The Scream. It's sort of like the predecessor to Macaulay Culkin in Home Alone. Exactly. With his hands on his cheeks, kind of looking like a ghost skeleton. Well, if you look past the eerie skull-shaped character in the front and into the background, you can see these vivid red streaks in the sky. And some scientists say that this was actually what the sky looked like in Norway about a decade before he painted this. this was due to the Krakatoa volcano eruption that spewed soot into the air all over the world and caused these amazing sunsets. Now, some scientists dispute that. They say the time gap was too large. Others will say that this was actually another type of cloud that you actually see in the northern latitudes called Nacreus clouds that are actually seen in and around Arctic and polar regions that actually reflect sunlight in these vivid colors. Seriously? So this may have actually been an early depiction of a phenomenon that we've only now begun to appreciate. So some people might be looking at that Munch painting and seeing, oh, wow, this is just some really weird portrayals of clouds with this sort of like red, orange, yellow colors. And then other people might be like, oh, no, he's totally serious. Like, that's actually what the clouds were like then. Well, maybe in that particular moment or that specific memory that he was evoking. I mean, that's fascinating. But the other thing to caveat is, of course, this is art and there is some artistic license. Paintings and art, they're constructed a lot of the time. You know, they're not photographs of the sky. They don't give you a real indication of how many of them there were, how often they were around. All these quantifiable factors which are important in understanding how our climate has changed. We get glimpses at the sky throughout history, but that's all we can get from human culture, really. So what have scientists learned from all of these glimpses of cloud history? I think it's a process right now, especially with the digitization of nautical records. The impossible-to-read handwriting of the crew of some whaling ship in the 18th century to try and pick out references to the weather. It's going to take time to actually get enough useful information out of them. Eventually, you know, you could use this to sort of put together a picture, a spotty picture, but a picture nonetheless of what the oceans and the skies looked like centuries ago. You know, it strikes me, Amir, that we're talking here about how there's so much we don't know about how clouds might change and behave in the future. There's probably even more we don't know about how clouds behaved in the past. Where does that leave us right now? I think it should leave us here with a little bit of humility to understand that, you know, there's a lot we still don't know and that there's still some things beyond our control. But it should also give us, you know, inspiration and motivation to study this further, that we know that clouds are going to be something that's hugely consequential for us, that these are really important blank spaces that we really need to fill in. And we should, you know, redouble our efforts to try to understand them. our relationship with our atmosphere is a crucially important one going forward and one way to help that is to be more connected to the atmosphere to realize that we don't live beneath the sky we live within it and the sky is an ocean that we inhabit we just happen to live on the bed of that ocean. So once you start appreciating clouds, you start appreciating your role in the world and your role as both an observer and a participant in the atmosphere. And so what we put into that ocean is not something separate from us. It's not something that happens above us. It is something that happens to us. And that may help you sort of center yourself in the world. When you notice out of the corner of your eye, something interesting or beautiful appear above you, be prepared to stop and look up. Just allow your imagination to drift along with the breeze for a few moments. To do that, to have a few moments with your head in the clouds, helps you keep your feet on the ground. Thanks to all the cloud experts we heard from in today's episode. Tom Warner, our fearless flyer from the beginning, Scott Collis, Angie Pendergrass, and Gavin Pritter-Penny. This episode was produced and co-reported by me, Meredith Hodnot, and edited by Brian Resnick, Bird Pinkerton, Jillian Weinberger, and Noam, who also made the music. We had sound design and mixing from Christian Ayala. Mandy Nguyen did the fact check for this episode, and Liz Kelly Nelson is the VP of Vox Audio. If you want some juicy, undulating pictures of clouds, video of Tom Warner's plane getting hit by lightning, or more information on the Cloud Appreciation Society, sign up for our newsletter. You can do that at vox.com slash unexplainable. And send us your thoughts on the show. Email us at unexplainable at vox.com. We read every email, and we'd love to hear what you're thinking. And if you like the show, tell a friend. Leave us a review or a rating. Do whatever you can to help bring new Unexplainable listeners into the fold. Unexplainable is a part of the Vox Media Podcast Network. Thank you for listening. And health officials cover heavy dilemmas.