# Can a giant mountain be used as a wind shield?

In my story, a whole scientific mission will land on a desert planet whose temperature in the day reaches sixty degrees Celsius, they will land near the North Pole, specifically next to a Great extinct volcanic mountain 15 km high with cinder cone shape.

Assuming (mostly unrealistic) that strong winds and deadly dust storms always come from the same direction, can the scientific mission be safe from the damages of these winds and storms if it uses the volcanic mountain as a shield? (That is, to land in a place where the volcanic mountain will serve as a shield protecting them from winds and storms)

(to scale)


Note 1: I mean winds of about 160 to 240 kph here

Note 2: The atmosphere of this planet is similar to that of Earth, but the gravity is slightly less

Note 3: If you find this kind of wind unrealistic then please give me your advice (And if you don't have advice, do nothing)

Note 4, which I think is unimportant: Specifically, the scientific mission will land at latitude 70 N or so

• When you say volcanic.. you mean it's conical? I.e. the wind can whip around the sides back and forth? Nov 28, 2021 at 11:20
• As long as the front of your car can support the mountain, I guess you can go with it.. but you won't be able to see much.. (Sorry, yeah I know where the door is -->[]) Nov 29, 2021 at 12:38
• Mount Kilimanjaro is a volcanic mountain that is not part of a mountain range. I couldn't find any instances of using Kilimanjaro as a wind barrier, but I found a few where climbers wished they had more shelter from the winds. Nov 29, 2021 at 13:01
• If you want a reasonably accurate answer, you need to download and run a mesoscale atmospheric model. There are a number available. I used to be somewhat familiar with MM5, but that was quite some time ago: a.atmos.washington.edu/~ovens/newwebpage/mm5-home.html Nov 30, 2021 at 3:51
• A mountain twice the height of Everest (and eight times the mass) would likely not be able to exist on a planet with Earth-like gravity. If it gets too tall, it will sink into the crust under its own weight. To get a larger mountain, you would need lower gravity (witness 25-km-tall Olympus Mons)—but that would entail a thinner atmosphere as well, and maybe 160-kph winds wouldn't be so much of a problem. Nov 30, 2021 at 17:07

Your party lands in a crater like that of Haleakala.

https://hanahou.com/14.4/quiet

Of course, national park status alone isn’t enough to make a place quiet, as any visit to Yellowstone will prove. But here an unusual mix of other factors comes into play: Huge sections of Haleakala are almost devoid of life, so there are no leaves or animals to make sound; the bowl and the cinder cones offer shelter from the wind; even the altitude, which keeps the crater cooler than the lowlands, slows and changes the way sound moves across the landscape.

Haleakala in Hawaii is a giant shield volcano as I imagine your volcano must be. Down in the crater, it is preternaturally quiet. The linked article does a good job of conveying both the silence. It is also eerie and bleak.

Set your party down in the old caldera. They will be protected there and you can also use elements of the actual Haleakala caldera for your story. If your party then ventures out into the surrounding lands they could go up and over the edge, or through a lava tube that pierces the wall.

• When I saw storms mentioned, I remembered a video about Hawaii and "rain shadow". This is even better. Nov 29, 2021 at 3:08
• @Alan Campbell: Rain shadow != wind shadow. The rain shadow is caused by the upwind air being forced up the mountain slope. This causes it to cool, so the moisture in the air falls as rain or snow. But the air keeps going, so the wind generally will be as strong, if not stronger, on the downwind side. For an example, look at the US west coast: Pacific storms come from the west, drop a good bit of rain on the lower coast range, drop even more crossing the Sierra, and the area to the east is mostly desert. But still gets strong winds from the storms. Nov 29, 2021 at 17:02
• Keep in mind that the actual caldera of Haleakala was long ago eroded away and was replaced by "river" valleys Nov 30, 2021 at 20:14

Probably not. The trouble is that while mountain chains can and do divert wind patterns a single mountain generally wont 'block' wind flow. What it will do is disrupt it. I suspect but cannot prove that it would disrupt the liner flow of the local winds and create vortex patterns as the wind current is 'split' and rolls around opposing sides of the mountain. Then on the 'lee' side of the mountain i.e. that side of the mountain that is opposite the direction the wind was flowing from the two streams would meet as opposing spiral flows that would cause turbulence as they recombined.

Immediately right up close against the side of the mountain there might be a degree of protection i.e. wind speeds would be reduced. But as you moved away the mountain the spiraling wake patterns of the wind generated as they rolled around the 'leading edge' on both sides would collide and recombine chaotically with sudden changes in speed and direction. So the result would be more turbulence rather than a island of calm (except perhaps within a few hundred meters of the base).

You really need someone with the appropriate software (e.g nautical or aeronautical engineering) to model it so that you get an accurate picture of what to expect. And they would need more data to feed into it.

• Von Kármán vortices. (Yes, the same Theodore von Kármán as in the Kármán line.) Nov 28, 2021 at 14:12
• Exactly , I should have just referred the poster to the Wikipedia article you linked. The video clip shows exactly what I was trying to describe.
– Mon
Nov 29, 2021 at 10:20
• I frequently hike in an area with mountains in a U around it (highest summit is nearly 2 miles above the terrain), the bottom of the U to the prevailing wind. It's a lot calmer in that area but there are definitely eddy issues. There can be areas that remain nearly calm when the forecast is 30 mph winds. Nov 30, 2021 at 3:38
• I somewhat recall a TV documentary about the high Andes. One thing that stuck in my mind, is that the mountain passes can form a deadly trap. If the wind blows from a certain direction, the mountains both dry the air, and intensify the gale. Fast-moving, high-altitude-thin, somewhat cold, extremely dry air is particularly deadly to travellers caught by it. Dec 1, 2021 at 15:25

# You never miss when you mark the bullseye after you throw the dart.

Your pole has complex wind systems and rugged mountains. You would need a supercomputer to simulate where the wind is lowest. Or, you could use a planet to do the simulation ... your planet. As in - look at the wind patterns in the polar region, see where they are weakest, and then say oooh, there's a sheltered spot to land a mission. Easy peasy.

Just make sure there aren't any terrorists on the loose with family atomics!

• This begs the question why that specific spot is particularly sheltered. Unless the geographic features of the surrounding are completely irrelevant for the plot and the visual presentation of the story. Dec 1, 2021 at 16:33
• I don't think it strains credulity to say that being in the lee of a high mountain has something to do with it. But if people say "well why doesn't the wind shift around to the west then", well, you've picked the spot where it doesn't. If the answer here required drawing a map to explain that, complete with Ferrell and polar cells and ocean currents and Ridiculously Resistant Ridges, then we'd still need that supercomputer. Dec 2, 2021 at 1:13

If you want it to provide serious protection, you do not want a simple conical mountain such as you depict.

What you want is a situation like Mount St. Helens, where the last explosion blew a cavity into the cone. A deep cavity.

This will not provide perfect protection, but if you situate it just right, it will ensure the majority of the wind goes "over their heads."

The mountain may to some extent protect them from winds coming from the other side, but it will also create its own winds, which can be stronger than the oncoming ones. Most mountain ranges have their own winds, with local names, like the "Washoe Zephyr", of which Mark Twain wrote:

"The "Washoe Zephyr" ... is a peculiarly Scriptural wind, in that no man knoweth "whence it cometh." That is to say, where it originates. It comes right over the mountains from the West, but when one crosses the ridge he does not find any of it on the other side! It probably is manufactured on the mountaintop for the occasion, and starts from there." (http://www.twainquotes.com/Zephyr.html )

• You got me curious... Twain was actually right ... when he said he didn't know where it comes from. Apparently that particular wind is more of a vacuum phenomenon, set off by the Great Basin. The mountain seems innocent after all, at least in that site's synopsis of the story. Nov 28, 2021 at 18:06
• @Mike Serfas: It's more a matter of needing both. But there are many other kinds of mountain winds, even though they lack the amusing description. The Santa Ana winds of Southern California, the Chinook of the Rockies, the Foehn of the Alps... Nov 29, 2021 at 4:11

This isn’t an answer, but perhaps more of an alternative.

With a massive volcano like that, there will almost certainly be extensive cave systems nearby (look up “lava tubes”). Perhaps your party can seek shelter within these caves during windstorms, or maybe they establish their entire base on the interior of the volcano. If that’s the case, an impending eruption could also make for quite a nice storyline!

I was windsurfing once near Kalepolepo on Maui when the wind gradually died to absolutely nothing. And I mean nothing (had to derig and paddle back in). Shortly afterwards a friend called to say I should head over to Kanaha where it was blowing 30 knots. What had happened was the wind had swung northwest and Kalepolepo (along with most of Maaleaea Bay) was completed sheltered from it by Pu'u Kukui. Like I said, there was not a breath of wind, yet it was blowing 30 knots an hours drive away.

Sure it will and it does protect them, assuming wind patterns are more or less consistent as you said it is, which is realistic enough, not like you say "unrealistic", wind patterns are a thing.

A single mountain is a bit on unrealistic side of things, however, let's omit that

It is 15 km high, and it is probably twice as wide at least 45-degree slopes(which isn't a random number), which makes it 30 km wide at its base.

It is possible to dream about a mountain chain, but a few km high, 10's km wide wall as good as a mountain chain for some area bhind it.

How big is that area is hard to tell without some aerodynamic simulation of such a cone, but it km's from its foot, you can place a city there, probably.

So yes, the answer is - yes, that mountain will offer protection.

• Single mountains are quite realistic. The Cascade volcanoes, for example, typically stand two to three times taller than the surrounding non-volcano peaks.
– Mark
Nov 28, 2021 at 20:36
• @Mark taller yes, why not, but not a standalone. I was referring to that time present answer from Mon, where he says about "mountain chains" in a sense it would be nice if they would be there, which I suspect they would, or else we imagine a single volcanic mountain, which is not on the border of tectonic plates, and that tall - which was created trough some pinhole in that tectonic plate or artificially created. Do not say it is impossible and I was comparing it to OP's "unrealistic winds from the same direction" which happen all the time on this planet. It is a joke attempt, failed, I guess. Nov 28, 2021 at 22:17
• @MolbOrg: Olympus Mons. 26 km above the surrounding terrain. Of course it's a shield volcano rather than a stratovolcano, so has a much more gradual slope. en.wikipedia.org/wiki/Olympus_Mons Nov 29, 2021 at 4:17
• @jamesqf not only that, gravity plays a significant role in this situation as well, especially on the slope, so as height. But sure it is a good example of OP's desired mountain. Now we spice it with a consistent wind pattern en.wikipedia.org/wiki/Saturn%27s_hexagon - and it is perfect. Nov 29, 2021 at 12:15

You have an example of this in the real world - the Indian subcontinent, which is protected from the winds that blow across Tibet and Central Asia by the Himalayas. It gets terribly hot in the subcontinent as a result, and that results in the monsoons.

A single conical mountain is unlikely to have too much of an effect at its foot.

You can get around this by having a cliff on the leeward side of the mountain, allowing the base to be much closer (horizontally) to the peak, and much more covered by the wind shadow. The balance would be that they would be at greater risk of landslides.

A single mountain isn't going to do all that much about the winds because the wind will just flow around the mountain. However, if you have a few mountains together the wind flows around the group of mountains, leaving a sheltered spot. This is basically a three-sided version of the crater answer.

• May it be so that 2 sided sheltering may be enough for something? Dec 2, 2021 at 2:20
• @MolbOrg I've never encountered a two-sided wind shelter but that doesn't say it couldn't exist. I'm simply aware of the three-sided example because I hike up there frequently and the nature of the terrain makes most of the trails start in the sheltered area. Dec 2, 2021 at 4:41
• Okay, I was going to catch with conundrum, but my bait failed, well then, main dish. Wind is not a magic, it is movement of air mass. There are plenty of places which regularly have winds, I live in one of those, not the strongest winds nothing special, but once it blows it strong enough to be sigificant annoyance when you ride a bike(if it isn't electric cheaters), or walk. A building, just one side wall, 10-25 m tall, does offer protection, I mean difference is obivious, and it makes sense to plan the route based on direction of wind and direction of streets along which houses are. Dec 2, 2021 at 13:13
• Mountain, 30km diameter of base and km's height and it is not enough for something in your opinion - how is it even possible. Sure we can be unshure which side and for which reasons is better, or size scale of good zone, but saying wind will just go around, making sure it blows everywhere, lol, what a joke, lol Dec 2, 2021 at 13:18

The mountain will most likely not provide significant protection.

To be able to answer your question better, we would also need to know size of the planet and rate of rotation around it's axis, in addition to gravity. If those are also comparable to Earth, then weather systems will have similar size and dynamics. Typical horizontal extent of non-tropical storms (e.g. hurricanes) on the Earth is on the order of 1000 km. This is much larger than the mountain in your scenario and it will not present significant obstacle to the storms. The mountain protrudes to stratosphere which helps, however, only by a very small amount (tip of the volcano). In order to create significant obstacle to weather sotorms, a mountain would ideally be a long range (north-south direction) with length of ~1000 km or more, and it would work even better if the height was up to the stratosphere or higher. For example something like the Cascades with the embedded volcanoes (Mt. Baker, Mt. Rainier, Mt. Hood,...), but higher on average.

On the other hand, the mountain would help with reducing risk of other types of storms (smaller in scale) and tornadoes.

Geographical location of 70 deg N is important, but it depends on the planet size, rate of rotation, temperature difference between poles and the equator (as mentioned before), what significance it will have on the type and strength of the storms at that latitude.

• OP's point isn't to change weather pattern with help of that mountain, but if such mountain can provide protection to the group. That shelter space even does not need to be measured in km's, 10x10 meters can suffice. Nov 30, 2021 at 2:05
• If 10x10 will suffice then look for a cliff or cave for shelter. If you only need shelter at that scale then the presence of the mountain is irrelevant. Dec 1, 2021 at 6:59
• @ChrisSchaller oh yeah, it so obivious that I even didn't bother mentioning it. OP wanna something, for some reason(idk, idc), in that comment I was just saying that bigger something does not mean altering weather on planetary scale, just with the help of one mountain. At least it is how I understood the question. Dec 2, 2021 at 2:19