Tropospheric Planning to Stratosphere Control
One thousand eight hundred metres above the surface of Equestria, Rainbow Dash and Twilight Sparkle flew through the network of cloud strata, columns, and rainbow cascades that made up the Cloudsdale Weather Factory. They crossed the paths of pegasus workers, dressed in regulation white coats and hard hats, flying to the different divisions of the industrial complex. Twilight looked left and right examining every detail. “It’s great to have another chance to tour the factory,” she said. “It’s so interesting to see everything going on here. I remember the first time you showed us around. It was fascinating to see how artificial rainbows are mixed. Why exactly do you need my help here this time?” She pushed her pink ear muffs aside to better hear her friend’s reply.
“Partly,” said Rainbow Dash, “because when dealing with bureaucrats, it helps to have a friend who is a princess with you.” Twilight nodded. That was the usual reason why ponies asked her to accompany them on such visits. She was surprised that Rainbow was direct enough to say so. “But mostly,” continued Rainbow, “because you can speak egghead.”
“What?”
“Some of these weather engineers spend all their time sitting on top of a cumulonimbus,” said Rainbow. “They have no idea how to talk to ordinary ponies. When we try to get answers, they try to intimidate us with lots of technical weather terms.”
“Didn’t you learn the technical weather terms when you trained as a weather pony?” asked Twilight.
“I napped through the boring classes. It’s not as if you actually need to understand that stuff to move clouds around and kick them into shape.”
“Rainbow—you know understanding the proper terminology is beneficial.”
“It doesn’t seem to stop these guys screwing up the weather. And it’s small town weather ponies who have to handle the complaints when they do.”
“Is that what’s happening now?”
“Exactly. From Ponyville to Fillydelphia everywhere is bitterly cold. You’d think that the windigos had returned, except with so many foals having fun playing in the snow, you couldn’t see much hatred for them to feed on. Winter has been fun, but it’s starting to get tiring, the cold is a real problem for elderly ponies, and we have winter wrap-up scheduled only weeks away. We need more warmth, but the air is still freezing.”
Twilight nodded. She could feel it.
“The townsponies blame the Ponyville weather team,” continued Rainbow, “but there’s nothing they can do and the weather factory won’t response to their enquiries. So—” she grinned smugly “—they decided to call in a top Wonderbolt to drill some answers out of them.”
“I’m not sure how your Wonderbolt status will help,” said Twilight.
“Seeing my awesomeness has a way of getting ponies to cooperate. You’ll see.”
They landed on a smooth grey cloud and walked through a golden-coloured door, engraved with an image of the sun and the moon, into a foyer area where they shook the frost off their wings and stomped their hooves to warm up. Rainbow Dash then trotted up to a desk next to a sign saying ‘General Enquiries’ and thrust her face up to a grey-maned pegasus mare.
“OK we want to know why the air is so bucking cold, and we want to get the answer quickly. Where do we go to find out?”
The elderly grey-maned mare stared back, pushed her thick-rimmed glasses up her snout, and paused before replying slowly. “We have a procedure to follow.” She pushed a paper form across the desk with a hoof. “We have to register all visitors to the factory now—new regulations following an incident last winter when a terrorist broke in and sabotaged the cloud production facility. If you could state your name, your organisation, and your business at the weather factory…”
“Rainbow Dash. Ponyville weather team (and the Wonderbolts). My business is to find out why you guys have screwed up and if you don’t tell us then you will be banned from future Wonderbolt shows and the Princess of Friendship is here ready to throw you in a dungeon and banish you from Equestria and…”
“Rainbow!” cried Twilight, “I would never—”
The receptionist rolled her eyes at the two mares. “Maybe you should go and have a chat with the Director of Tropospheric Planning. Third door on the right.”
Rainbow Dash trotted off along the corridor looking smug followed by an irritated princess.
The Director of Tropospheric Planning sat behind her white desk with her forehooves pressed together. She had a fluffy pink mane and lilac coat. On the wall of her office were framed pictures of prize-winning clouds and a pinboard covered with weather schedules and lists of weather orders from towns across Equestria. She answered questions calmly, without much interest.
“You ask why the weather is cold. Well it is winter.”
Rainbow Dash gnashed her teeth. “I know it is winter. But it isn’t normal when you can’t fly outside without icicles forming on your wings?”
“Have you tried moving the clouds to the side to let the sun through?”
“For the love of Celestia!” Rainbow glared at the senior weather director. “Yes we have tried that. Do you think we’re stupid? I clear the Ponyville sky every day (except when I’m training with the Wonderbolts). The sun is fine, but the air is too cold. There’s something wrong with the weather. You broke it!”
The director stiffened. “We have met our targets for cloud delivery.” She pointed a hoof at the schedule on the pinboard. “I have seen reports indicating temperatures are abnormally low for this time of year. But that’s nothing to do with us. I expect that it has something to do with the polar vortex. You’d better talk to them in Stratosphere Control.”
“Where are Stratosphere Control?” asked Twilight.
The director pointed a hoof at the ceiling. Rainbow Dash raised her eyes. “Should’ve known it would have something to do with them.”
The director smiled as she watched them walk out of the office.
“What is Stratosphere Control?” Twilight asked Rainbow Dash as they flew upwards towards the higher offices of the weather factory.
“They’re the worst eggheads,” said Rainbow. “Most weather ponies work in the troposphere—from the ground to about ten kilometres up. This is where the real weather is: clouds, rainbows, snowflakes and so on. Tropospheric Planning oversee cloud production and deal with weather ponies across Equestria. Higher up, we have the stratosphere. The specialist team who manage that talk about weird stuff like ozone levels and nopony working on real weather understand them.”
“Really?” Twilight was intrigued.
“The weather factory is divided into different divisions.” Rainbow sweep a hoof across their view of the tiered industrial cloudscape, “who don’t like to talk to each other. Some of them actually do stuff—you know—make clouds, mix rainbows. But a lot of them in the higher strata divisions wouldn’t know what to do if a snowball hit them in the face. Stratosphere Control and Mesosphere Maintenance are the worst. They say they are doing important backend weather maintenance, but they can never explain exactly what that is to anypony.”
“I’m expect it’s not that simple,” said Twilight.
They flew past the offices of the Jet Stream Navigation Agency and Snowflake Quality Control, along a wide cloud bridge and until they reach a building with a set of columns on the roof supporting a spherical structure. A sign by the door said, ‘Stratosphere Control. Enquiries by appointment only.’ Rainbow pushed open the door and marched down corridor lined with lockers and clothes pegs holding flight jackets and goggles. At the end of this another doorway led into a meeting room where three pegasus ponies were standing at a table covered with maps and charts. The name tags clipped onto their factory-issue white coats identified them as Stratosphere Engineers Wind Ripple, Comma Cloud and Convection Current.
“OK why are you guys making it so cold?”
Comma Cloud, a purple-maned green pegasus mare, looked up and recognised their Wonderbolt visitor. “Rainbow Dash, what are you doing here?”
“I’m here because I have every pony in Ponyville reporting that the weather is out of order, and we can shift the clouds around all we like but it’s not getting any warmer.”
“That’s a general enquiry—you should ask the mare at the main reception desk. Go back outside—down three strata—big gold door to the left of the main forum.” She turned back to her pressure chart.
Rainbow Dash was not deterred. “The mare down in Tropospheric Planning says it’s your doing because you made a polar vortex.”
The three ponies lifted their heads and returned angry looks.
“That's rubbish,” said Wind Ripple.
“Are you saying you haven’t made a polar vortex?” asked Rainbow.
“No, we make one every year.”
They turned away from the visitors and just spoke to one another.
“Every time they lose control of their winds they find some excuse to blame it on us,” said Convection Current.
“Have they been telling lies to the press again? Every time things get cold they blame it on the polar vortex,” said Wind Ripple.
“Maybe this is something to do with that SSW event we had last month,” said Comma Cloud.
“They shouldn’t be blaming us. Cold-air outbreaks on the ground are definitely a tropospheric responsibility,” said Convection Current.
After watching the three ponies talk to themselves, Twilight decided to ask a question. She walked around the table to face them. “What exactly is the polar vortex?”
They turned back to face her having apparently forgotten they had visitors.
“It’s a westerly zonal flow,” said Wind Ripple, “defined by a region of high potential vorticity.”
“Eggheads!” Rainbow whispered in Twilight’s ear.
Twilight ignored her. “And what's an SSW event?” she asked.
“A Sudden Stratospheric Warming,” said Comma Cloud.
The conversation was interrupted by a shrill bell blast from a whistle outside the building. Breaking into a smiles, the stratosphere management team left the table and moved towards the door.
“What’s going on?” asked Twilight.
“It’s lunch time,” said Comma Cloud. “Sorry—we got to rush or by the time we get to the canteen all the good seats will be taken.” They flew out of the room.
Twilight thumped a hoof against her forehead in frustration but Rainbow Dash smiled. “Hey we might as well get some lunch. I heard the food here is pretty good.
They followed the tails of the pegasi flying towards the factory dining hall where they found workers collecting bowls of salad, hayburgers, fries and other food and sitting at long cloud benches.
“Maybe we should chat with some of them,” suggested Twilight as she levitated a plate from the buffet. “If the directors and engineers can’t explain what is going on, maybe these workers can. Let’s ask a few discrete questions.”
Rainbow Dash sat down at a table next to a pink-maned mare and opened the conversation with her usual level of discretion. “Hey – why is it so cold at the moment?”
“Don’t ask us, we work in Administration and Equine Resources,” she answered without looking up from her food.
“Has your heating system broken down?” asked a brown stallion sitting opposite. “It was fine in our office. Report it to Maintenance, they usually fix things but you do need to pester them sometimes.”
“I’m not talking about inside.” Rainbow raised her voice so loud that everypony at the table turned to look at her. “I mean why is it freezing outside? This is supposed to be the weather factory. Why does nopony know about the weather?”
The table fell silent and everyone stared at Rainbow and Twilight. Twilight smiled nervously. “We heard it has something to do with the polar vortex.”
An old mare with a pale blue coat and cutie mark of a ball of yarn answered in a conspiratorial whisper. “The polar vortex is a dangerous creature. Or so I’ve heard.” As she spoke, everypony leaned closer to hear what she was saying. “They told me about it on my first shift over a thousand moons ago. I sometimes hear the stratosphere team talking about it. It lives in the Far North. It's related to the ursas. Most of the time it stays asleep under the ice, but when it wakes up it gets cranky and it sends cold shivers across the world.”
“That’s just an old mares’ tale.”
The old mare smiled and nodded her head. “Just like the sonic rainboom.”
Silence fell across the table. Everypony shivered. Eventually a navy stallion with a spiky blue mane spoke up. “I heard that not all of the Storm King’s army was defeated. There is still a unit of storm troops hiding in the clouds and they are wrecking the weather. Could they have woken a polar vortex?”
The ponies were no longer paying attention to their food and looked worried. Twilight tried to intervene. “Everypony keep calm. We defeated the Storm King and there’s nothing to suggest any of his storm guards pose a risk to Equestria now.”
Nopony was listening. “We asked the management to do a full safety assessment after the Storm King incident. The delivery team have to fly out among these rogue clouds.”
“They’ve gone and unleashed another air-borne monster! Do Occupational Safety know about this?”
“I doubt it. The executive committee would never admit it.”
“We need to tell them.”
“That won’t do anything. They never listen. Remember the terrorist incident last winter? We told them we’d seen a strange pony on site and a drone buzzing around, but they took no action. Next thing we know the Number 5 compressor blows up and fires three seasons worth of snow onto Ponyville. And we had to repair the mess.”
“Get a union rep to talk to them. Ask Lightning Strike or Industrial Action. They know how to deal with managers. This really isn’t on—the exec are covering up their mistakes and putting workers at risk.”
“They need to offer us hazard pay at least!”
One pony sounded more sceptical. “Hang on a minute—I’m sure they are covering up their mistakes—they always are—but do we know for sure that there’s a polar vortex out there?”
“Fluffy Clouds said something about it last week.”
The rest of the table nodded. “It must be true.”
Twilight and Rainbow moved back from the table leaving the factory workers talking. Twilight put her hoof to her forehead and shook it despairingly. “This is not getting us anywhere. Do none of these ponies really know what is going on here?”
Rainbow Dash grinned. “Yeah I’m sure in Canterlot Castle and Princess Celestia’s School every member of staff knows exactly what everypony else is doing,” she said sarcastically. “But that’s not quite how the weather factory works.”
Twilight put her hoof down and sighed. Then she had an idea. “Let’s go and visit Fluttershy’s parents,” she said. “Didn’t her father work here before he retired? Maybe he can give us some advice.”
Rainbow sighed. “Why not? It’s always fun visiting them and they can’t know any less than this lot. I just hope Zephyr isn’t at home.”
“Last I heard he was in Las Pegasus.”
They had an easy glide down to a pleasant cloudscaped suburb with rainbow borders marking out the fluffy white gardens. They found Mr Shy dusting the bell jars holding his cloud collection in his back house.
“Rainbow Dash! Princess Twilight!” The retired factory worker smiled nervously. Twilight looked past him at the neat array of shelves. Her eyes lit up and mouth fell open in a similar way to when she entered a new library.
“Wow! You’ve catalogued all these cloud samples and arranged them by their date of production, and classification—Cirrus, Cirro Cumulus, Cirro Stratus, Cumulo Stratus, Cumulus, Nimbus, Straus—she read the shelf labels moving from top to bottom, left to right. This is amazing.”
Mr Shy relaxed. “I wanted to get them in a proper order. These are really special pieces that need a proper showcase. See this—” he held up a tall cylindrical jar housing a grey fluffy column “it’s from the first cumulonimbus run after we installed the Mark III supercooler—it took weeks to fine tune the parameters to get the ice crystals just right. And that—” he proudly pointed at a jar sitting on a prominent shelf containing a cirrus cloud. “—is from a special commission we did for Princess Cadance and Prince Shining Armour’s wedding. We did twelve runs until we got the curls just right. And—”
Rainbow Dash thought it best to interrupt before being shown more clouds. “Can you tell us about the factory?”
Mr Shy nodded. His white moustache twitched. “Yes… I’m retired now, but I worked there for more seasons than I can remember.”
“We want to find out why they are making the air so wing-numbingly-cold at the moment.”
“I just worked in Cloud Production. I don’t know anything about that. You should ask them at the general enquiries desk.”
“Done that. They sent us to Tropospheric Planning, who told us to talk to Stratosphere Control. We have spent the morning flying from cloud to cloud, but no one was able to explain it. All we learnt it’s to do with some polar vortex.”
“Polar Vortex? You mean the mare who sings in that folk group with Fluffy Clouds?”
“Err—probably not.”
There was a long pause before Twilight asked, “Is there anypony who might be able to tell us what is going on?”
Mr Shy thought about this for a while before replying. “Talk to Coriolis.”
“Who is Coriolis?”
“She works in Weather Forecasting.”
“Weather Forecasting? Forecasting? What the hay is that?”
“It was an experimental research unit set up some years ago. I think the idea was to predict what the weather will be in the future.”
“But you make the weather! Surely you just need to look at the schedule.”
“I never really understood it…” Mr Shy paused and ran a hoof across his moustache. “But Coriolis was a good friend, and she was the one pony I knew who seemed to know what was going on at the factory. She always noticed if anything was wrong with a cloud line. And she had lots of gadgets in her lab. Maybe she had found a way to listen in to the directors' meetings.”
“Where can we find Coriolis?”
“It’s probably best if I come with you.”
They flew back to the factory together, this time away from the main throughway. Mr Shy took a short cut, weaving through a labyrinth of small inter-cloud passages. They reached an unmarked door on a discrete cloud somewhere underneath Stratosphere Control. The sign by the door was covered with too much frost to be able to read it. He tapped a hoof against the door before walking in.
Twilight and Rainbow gasped. Inside, the room was larger than expected. There were no windows, but it was brightly lit by light coming through the transparent cloud ceiling. On the walls were magically projected maps showing the cloud cover, air pressure, and temperature across Equestria, along with other things neither of them could recognise. In the centre of the room was a large globe, magically illuminated in a full rainbow spectrum of colours, which moved as they watched.
Mr Shy went to great an old friend.
“Coriolis!”
“’Shy!”
Coriolis gave the old stallion a friendly hug. She was a middle-aged mare with a blue-green coat and a ghost white mane and tail that both needed brushing. Lose hairs curled out like strands of cirrus cloud.
“How are you now?” he asked.
“I’m doing fine. I got the last Head of Administration to approve our budget before she left, so we can now get a new radar system, and the new head hasn’t found out that we exist yet. Suits us fine. What brings you here? Is retirement getting a bit dull? Do you need a job to do?”
“Rainbow Dash and Twilight Sparkle here have some weather questions that I thought you might be able to answer.”
“Rainbow Dash!” Coriolis noticed the celebrity pegasus and her face lit up. “Will you sign my Wonderbolts poster?”
This made Mr Shy giggle. “She has more Wonderbolts figures and prints than anyone else I know,” he said to Rainbow and Twilight.
“It’s no crazier than filling your house with jars of clouds,” Coriolis pointed out.
Twilight walked up to the glowing globe. The moving pattern of colours reflected in her wide eyes. “What’s this showing? It looks amazing.”
“We use this to watch the weather patterns across the world,” said Coriolis proudly. “It’s now showing air temperature—measured by magical probes looking down from space at the infrared light—the red shows the hottest air, the violet is coldest.”
Twilight cast her eyes across the rainbow bands. Beneath this she could make out the outline of the coastline of Equestria and surrounding lands. The equator was red, with bands of yellow above this, while the pole was covered by a purple shape, extending down to Equestria.
“And we don’t just look at temperature.” Coriolis tapped a hoof against her globe to trigger a new display. “This shows the wind speed, measured by flashing a laser into the air and looking at the shift of reflected light.” The globe displayed an image of tiny arrows pointing in the direction of wind flow across the planet. “And we have more instruments looking down from space, and up from the ground. Our motto here is Monitor Everything!”
Twilight nodded in approval. “Then you can forecast what will happen next?” she asked.
“Exactly,” replied Coriolis. “We feed this data into computer models, and simulate how the weather will change in the future.”
“Can you do that? How well can you predict the future?”
“Well, we can do pretty well for the next few days. We could do better if the weather ponies would stop interfering with the laws of physics. The biggest uncertainty in our models is the whims of division managers.”
She turned back to Rainbow Dash. “So will you stamp a hoof on my poster?”
Rainbow grinned and leant back against the wall with a pose deployed to increase her coolness by a significant percentage. “Sure I can. On one condition. We’ve spent today being passed from cloud to cloud as we asked ponies why it’s so cold. We are getting pretty sick of being told we just need to move the colds to the side to let the sun through. So can you give us answers to our questions about what is going on with the weather.”
Coriolis grinned back. She relished a challenge. She bumped Dash’s hoof.
“Deal.”
“OK… Let’s start with: what is a polar vortex?”
This made Coriolis laugh. “Nice one. Yeah—ask three weather ponies that question and chances are you’ll get at least two different answers.” She paused to collect her thought. “A polar vortex is a band of cold air swirling around the globe, centred on the north and south poles. There are actually two polar vortices around each pole, one up in the stratosphere, and one in the troposphere. The stratospheric one is what most weather ponies mean when they use the term. Stratosphere Control set it up each winter and keep the cold air circulating high above the arctic. The tropospheric polar vortex exists all year. It’s bigger and circles around the planet closer to the ground, a bit further away from the pole, bounded by the jet stream.”
She beckoned them over to the glowing sphere and tapped this again. “This projection shows the temperature of the air about four kilometres above the surface, the polar jet stream moves around and sometimes comes further south than usual bringing cold air into Equestria.”
They looked at the coloured mass over the northern hemisphere, especially a purple extension covering the land of the Equestria.
“And it is the tropospheric polar vortex that’s making it so cold across Equestria?” asked Rainbow.
“Yes—but just because its lower edge has pushed into Equestria recently.”
“You mean Stratosphere Control were right after all and it’s all the fault of the troposphere team?”
Coriolis laughed again. “Well that’s probably what they would say—it's the jet stream team not properly maintaining the boundaries. But it’s not quite that simple. The stratospheric polar vortex can have an effect on tropospheric weather.”
“How can that happen?” asked Twilight.
“Sometimes the stratospheric vortex becomes unstable. The wind slows down and can even switch direction or the vortex can break into two. Then the stratospheric air warms up. We saw that a few weeks ago.” She pointed a hoof at the global display showing two separate eddies swirling somewhere above Yakyakistan.
“Is that the Sudden Stratospheric Warming we heard about,” asked Twilight.
“That's it. When this happens cold air in the polar vortex falls into the troposphere, pushing the tropospheric polar vortex further south. Warm air up north makes it colder than usual this far south.”
“Yes.”
“So it was the stratosphere team’s fault!” said Rainbow.
“In a way. But stratospheric warming events are usually triggered by things in the troposphere. When the jet stream becomes slower and starts to meander, it can disrupt the stratosphere and the cause the polar vortex to split.”
“Are the jet stream maintenance crew getting sloppy?” asked Rainbow.
“I don't think so. They work hard and are always boasting about how fast they can fly from Vanhoover to Manehattan. These events seem to have become more frequent since the return of the Crystal Empire. Maybe it is connected with the reduced snow cover, but we don’t know for sure. It might also be indirectly due to the Storm King’s interference or something else entirely.”
“This sounds like an organisation problem,” said Twilight. “It's like the Ponyville Winter Wrap Up, but rather bigger. Is there anyone is in the weather factory prepared to take responsibility for what’s going on?”
“Take responsibility? You kidding!” Coriolis laughed. “But they wouldn’t be being entirely honest if they said they could control it. The troposphere and stratosphere are interconnected. Weather is a chaotic system where one small thing can lead to so many changes it becomes impossible to say what was the original cause of something like this. You might as well blame the proverbial butterfly flapping its wings in Saddle Arabia. All we can do is monitor it, try to spot patterns and understand the underlying processes so we can create the best conditions for a stable weather system in the future.”
Rainbow and Twilight nodded slowly as they listened to Coriolis’s response. They had finally got the answer they were seeking, but didn’t feel as satisfied as they had imagined.
“And there’s no monster?” said Rainbow.
“Not that I know of.” Coriolis shook her head. “The polar vortex is just a regular feature of the Equestrian climate. Which is not to say that there aren’t any monsters out there threatening the safety of Equestria. Based on past data, I would say there probably are.”
Twilight nodded to this. Coriolis passed a poster showing Rainbow Dash and other Wonderbolts posing. Rainbow stamped an inked hoof on the surface. “Well thanks for the explanation,” she said. “Although the Ponyville weather team were rather hoping you could do something to take off the chill. Isn’t there any easy way to make it warmer?”
“Not really.” Coriolis shook her head again. “Just wait. Our simulations show it will probably warm up in a week. Better just get out your sledge and ice skates and enjoy it. You could put a woolly hat on? Or—” she smiled mischievously “—you could, you know, move the clouds to the side to let the sun through.”
Author's Note
Thank you for reading the story. I hope you enjoyed it. See my blog for more details about the polar vortex and other science topics.
Before you go I have a small request. As a scientist, I love data. Would you please help me with my research project Assessment of the impact and potential of My Little Pony fan fiction as a medium for science communication by completing this short reader questionnaire? Ten very simple questions.
Click here: https://goo.gl/forms/4d1oq7ybBxU7cv963
