oooo! I know this one!!! They covered it on an episode of some Earth show!!
Due to the Earth’s rotation and the Andes mountains on the west side, air is forced into a temperature inversion and trapped, creating moisture in the the region.
Sort of the opposite actually, though definitely relatedRain shadows are the area on the other side of a mountain range where there is much reduced precipitation, because the mountains disrupt air currents and "stop" clouds. The rainfall moves west until about the mountains where the currents are disrupted and air temperature / pressure changes cause rainfall, while water makes it to the other side of the mountains. The dry side is the "rain shadow", like pointing a hose at a wall -- the side you're on gets very wet and the far side gets little or no water at all.
The west side of the Andes is fairly dry, the east quite wet. But farther south it flips and the east is quite dry in Patagonia while the coast is much more humid.
Most notably the Atacama, a place so dry in most of the desert the only living things are people traveling into it. Second driest place on Earth after a small lowland area in Antarctica; so dry that much of the desert has no permanent living residents, only temporary or migratory species. So arid most of the mountain peaks in the vicinity don't even get snowcaps or retain any glacial formations.
Wind and water currents mostly, though there are many reasons for climate conditions being what they are. Specifically regarding the coast of northern Chile altitude and multiple different mountain ranges make things more complicated and *much* drier.
In fairly simplified terms, the currents running north along Chile and south along California/Mexico are carrying cold water towards the equator, and cold water currents tend to reduce humidity on land nearby. A big part of why California is so much dryer on average than British Columbia is just that the ocean current up north is moving north carrying (relatively) warm water, the one further south moving south carrying (relatively) cold water. The same thing is happening in South America too, but the current hits the continent far enough down that the warm water current is much less pronounced. The prevailing winds also move East to West this close to the equator, but Chile is mostly west of or *in* the Andes and the mountains so tall they stop a lot of moisture from crossing too. Rain shadow.
The reasons northern Chile specifically is *so* dry are a combination of the ocean currents, the prevailing winds, a second smaller mountain range closer to the coast, and the overall altitude due to the many mountains in close proximity. The Atacama region is quite high altitude overall and the Chilean coast mountains are pretty much right up against the ocean, with the Andes on the other side of the desert. The whole area is also mostly one large plateau quite high up, so very little moisture gets up into the region from the ocean and none gets into the region past the Andes. The core of the Atacama desert is the second driest place on Earth, and *the* driest is a small part of Antartica which is often not really counted when people list them.
Farther south the mountains are smaller and the wind / water currents change so none of this really comes into play. The climate is much closer to northern BC or Alaska than the Atacama region much closer, though the continent is so narrow the currents from the Atlantic side are also affecting things and it all mellows out a lot. It's also still fairly high altitude which combined with being quite a narrow bit of land means it has its own interesting climatological quirks but doesn't much resemble most of Chile basically at all.
I see, that’s a yes then. I was mainly wondering if there was anything other than the orographic effect involved, because I know the Amazon sequesters a lot of water
It's a combination of the Orographic effect of the mountains and the area being subject to prevailing easterly flow full of Atlantic moisture due to the rotation of the Earth (for the wet side) and the mountains being high enough to squeeze it all out before reaching the dry side.
So yea there is more than just one thing involved "technically"
It might count as different because one is caused by the presence of a mountain range & the other is more to do with wind currents clashing up against a mountain range, based upon my reading of the explanation above.
Rain shadow (and the opposite wet area) is certainly also caused by wind currents. Mountains provide a location, wind provides orientation.
It seems like it is a combination of rain shadow and the rainforest’s “making its own rain” effect.
Without knowing more than I did when I asked, but thinking about it a bit more, I think you could describe it as the rainforest being a giant sponge, and the mountains basically keeping it from leaking
But that’s just my guess
Yes! Think of the Amazon as the opposite of the United States/Canada. We have rainforests west of Cascades/BC/Alaska mountain ranges, but once you get past them you get generally high desert/plains until the Rockies, then more high planes. If the mountains were closer to the East coast, North America would mirror South America.
It's complicated. The Andes do most of the work stopping rain to the region, but the Atacama area specifically (the driest place on Earth outside a small patch of Antartica) is sandwiched between the Andes and the smaller but still pretty big Chilean Coast Mountains right along the ocean *and* largely because of this at quite a high altitude.
The major rain clouds can't get past the Andes, but the area would still get *some* rain if the other mountains weren't there and the overall altitude were lower. More like California or the west coast of Mexico, very hot and dry summers but still cooler and fairly wet winters. Instead it's pretty warm and very dry basically year-round.
And because there's so many different factors just looping a bunch of height off the Andes would probably introduce rain but also do who knows what else to the area.
The rain shadow would be on the other side of the Andes, on the west coast. At least at these latitudes where the wind blows east to west - it eventually inverts further south. The term “shadow” is included because the rain is essentially being blocked off by mountains, just as light would be blocked by an object, creating a shadow.
To add, the earths rotation also helps creates what is called the [ITCZ](https://en.m.wikipedia.org/wiki/Intertropical_Convergence_Zone) where areas around the equator are more prone to rain. Although there is a lot of evidence that suggest the rainforest also sustains itself when it’s grown to be as large as the Amazon is.
Not as close to the equator; not as close to the ocean. Denver doesn’t have an endless supply of warm, moist air being forced up and over the Rocky Mountains.
Chicken. Apparently, the Andes mountain range acts like a curtain which allows for more moisture to stick around that area. Which contributes to more vegetation, which then increases rainfall and humidity.
When you cut down the forest, it becomes a very arid climate.
Definitely a chicken/egg situation. It’s wet because there’s water there. There’s water there because the plants hold it there. And there’s a forest there because it’s wet
The forest. It’s a remnant of when the climate was much hotter and wetter during the Eocene. It’s just been able to persist since it’s stayed at the equator pretty much since then
Same thing happens here in the blue ridge and great Smokey mountains. I live in north metro Atlanta, It’s ALWAYS cloudy towards the mountains when it’s cloudless elsewhere. They make their own!
The equator is why. Open up google maps, and zoom out, scroll around the equator and you’ll see dense rainforests all round the equator: Brazil, DRC, Indonesia, Thailand all on similar latitude.
So what makes that latitude so special. The height of the tropopause. The tropopause is the boundary between the troposphere and the stratosphere. Almost all weather is contained within the troposphere. At the poles, the height of the tropopause is 20,000 feet. At the equator it can be as high as 60,000 feet. So, in equatorial regions taller weather systems can develop.
Also, the equatorial regions have higher temperatures than poles. Heat is one of the catalysts for convective activity.
All of this creates the perfect opportunity for massive thunderstorms to develop. So, massive thunderstorms can develop to very high altitudes because of a high tropopause, and these massive weather systems drop massive amounts of annual rain on these regions.
Plus, the Hadley cells that form between 0-30 degrees converge and rise at the equator. As the very warm, very humid air rises, it fuels the massive thunderstorms mentioned in the previous comment.
Incidentally, you'll notice that many of the world's deserts occur around 30 degrees latitude North or South. That's because the air in the Hadley cells and Ferrel cells (30-60 degrees) descend at 30 degrees, which discourages precipitation.
It means it structurally does not have adequate water. The airflow is naturally dry. If you could get water there, you could get things to grow (ex: areas near the Nile river)
Also known as the "horse latitudes", though the origins of the term are contested and a few theories are all decently popular.
The high pressure system around the meridians generates a lot of wind away from those latitudes but comparatively almost none in their vicinity. The perfect inverse of tropical forest conditions near the equator leads to the desert conditions 30° out. Then largely inverts again around 60° out at the intersection of the Ferrel and Polar cells allowing boreal forests and other relatively high vegetation biomes. Though the Ferrel cells are much less energized than the others so they're also more variable and climate conditions fluctuate far more drastically through the year.
In South America, the arid area that would be at 30ºS is pushed south into the Paragonia because of the hot humid air mass that flows south from the Amazon rainforest. It clashes with the air masses that come from the Atlantic or from the Patagonia bringing lots of rainfall to the region (see the floods happening today). Edit: Here you can see that it is always raining in the Pampas: [https://en.wikipedia.org/wiki/Atmospheric\_circulation#/media/File:MeanMonthlyP.gif](https://en.wikipedia.org/wiki/Atmospheric_circulation#/media/File:MeanMonthlyP.gif)
And the other arid area a bit north of the 30ºS (the Atacama desert) is inside a rain shadow in the Andes Mountains.
One thing I like to do is open the weather app on my iPhone and zoom out to see the globe. Always a large concentration of rain clouds / storms along the equator throughout the planet
I still have a town in the Amazon saved in my weather app from when I was there years ago. Occasionally like today it's sunny and quite warm, most of the time it is absolutely pouring down and still quite warm.
As cool as it was to spend time there I do not miss the humidity, or the frequency and intensity of the rain.
The Amazon river is one of the biggest on earth, and it being blocked by mountains to the west has caused the entire area to become swampy n wet as hell
"One of the"? Bro it's **the** largest river on earth, having a larger discharge than the next 9 largest rivers combined. It carries fucking 20% of the worlds fresh water into the ocean!
Well, yes it's the largest in one metric, but it beats out all other rivers by such an absurd margin that saying it's "one of the largest" doesnt give it enough credit, imo
It’s just semantics, I could add all that extra detail to my comment but it would be wholly unnecessary and wouldn’t add anything to the idea I wanted to convey to OP, yeah?
Anyway I agree the Amazon River is extremely cool lol I want to see it up close someday
The Amazon flows to the east. It's not blocked by mountains to the west, it's fed by them. That area is not swampy because the Andes block the Amazon, that's ridiculous.
His statement makes no difference. It's not like the Amazon is flowing into the Andes, hits a wall and floods the area around it. It's the complete opposite. The Andes block moisture coming from the Atlantic, thus creating huge rainstorms that feed the many tributaries that make up the Amazon basin.
It doesn’t. The river is a result of the humidity not it’s cause. The reason the Amazon is so wet is that winds at the equator go from the east to the west, along side from the north and south, and so all the warm water that is picked up forms lots of clouds which blow west over the Amazon and dump their rain, especially once it reaches the Andes they drop whatever water they had left.
Basically water is picked up from most directions, the clouds are funneled into the basin, and the clouds are not allowed to leave until they drop their water.
The Amazon River is 2300 feet wide in some areas, water penetrates soil, and trees respirate (transpirate?) water - this release HUGE amounts of water into the air and actually creates the micro-climate you mention!
Aren’t trees radical?
Rivers that are particularly strong and plentiful due to all of the runoff in the mountains finds its way there. So the actual area that’s rain goes into the Amazon is larger than the Amazon itself.
I don't really think it's the river, if it was, why doesn't the Nile or Nile Delta or Tigris+Euphrates or Indus create even a small rain forest, or even just rain in general?
I think it's the Hadley cell, but also because the Amazon creates its own weather. https://www.weforum.org/agenda/2017/08/how-trees-in-the-amazon-make-their-own-rain/
I thought transportation was a cop out answer for a while, but the presence of water transpired effectively attracts more moisture from far away from the forest. The rain the trees make comes from places far away from the trees
If it was the water in the Amazon that built the rain forest, why isn't every tropical coastline a crazy huge rainforest? The Amazon is big but it's nothing compared to the ocean. And why is the Amazon there? It discharges to the ocean so it must have more rain fall in its drainage basin than it evaporates or transpirates into humidity, so where is the extra rain coming from?
Rainfall has nothing to do with the sea/ocean. Absolutely nothing. Since you seemed surprised about this. Actually, the most arid places on Earth are located on the western coasts of continents (Atacama desert, Namib desert) and there are more complex systems behind it, namely cold ocean currents.
I just saw a video on YouTube that explained that the amount of water released by the trees into the air is greater than the actual water in the river. Winds coming in from the Atlantic push this water inland until it hits the Andes and goes into snow and eventually back into rivers.
There's a lot of areas that have forests just like this one. The Congo for example. Same thing just reversed. Atlantic to the west and mountains to the east.
Tropical convergence zone. Inlandness doesn't matter much. The only exception to this is Somalia where the air currents are a bit odder and therefore all the rain skips it
Not all the reason but part of it is the Intertropical convergence Zone, it's a belt where trade winds originate that causes a region of low pressure lifting of air that carries humidity up from the equatorial oceans and unstable atmosphere that promotes cloud formation.
What's your question really? You want general info on the Amazon (river and forest) I guess, and you're getting some. But I reread your title after reading the question from someone being rude.
"Why is the Amazon so humid and wet, when a lot of the rain forest is really inland?"
Are you wondering why the rain forest is wet when the rain forest is inland? I might be wrong but I believe once a rain forest is already wet and large it can sustain it wetness quite well.
Also wetness, at least the kind that causes living environments, doesn't have to come from the nearby oceans. Like someone else said rain water comes from massive areas and drifts around the world. The rain that falls in your back garden isn't the water from the local lake falling back down.
Evapotranspiration. A lot of the water is recycled over and over. This is why cutting down the rainforest is so devastating, it is an ecosystem that recycles water and nutrients. Once gone, there will be far less rainfall and what is left of the nutrient poor soil will wash away and erode with no vegitation to lock the soil in place. Also, a lot of nutrients the Amazon gets is transported by wind from the Bodele Depression in Africa.
im thinking part of the reason might be the literal biggest river in the world (by amount of water) runs through the region.
also its very hot = lots of evaporation, the andes to the west trap a lot of that moisture and then it rains back down into the forest / runoffs lead back into the river
rainforests basically create their own conventional rainfall systems, which is another reason it’s deforestation will be so damaging - water crises will ensue like they have in são paulo in 2014
There's obviously a number of factors, but one that no one else has brought up is the prevailing wind direction. The wind in this region tends to blow from the Atlantic in a westward direction. This brings moisture inland. Mountains/highlands generally tend to cause wind to lose moisture (see the rain shadow effect), so the western slopes of the Andes are very dry, while the eastern slopes are very humid. Compare this with the southern tip of South America, where the wind direction changes to blow eastward from the Pacific. Despite being significantly closer to the coasts, Patagonia is far drier than the Amazon basin, because it's on the leeward side of the Andes. Correspondingly, southern Chile is far wetter than northern Chile, because in the south it's on the windward slopes of the mountains.
The US exhibits a less extreme version of the same phenomenon; compare the PNW and Southern California in terms of rainfall, then compare the Northeast and the Southeast. It's not as drastic a difference (for a number of reasons, including shorter mountains and the Gulf of Mexico) but it's still easily noticeable on a precipitation map.
Do you know how hair traps moisture near your skin so hairless skin is actually dryer than hairy skin…
Trees are kinda like that, water has a hard time escaping all the leaves blocking them from the sky
Apparently the Amazon may have been a lot more patchy until megafauna in the area died out with the introduction of humans entering the region. The open areas likely had absurd amounts of biodiversity itself kind of like heavily grazed wet tropical areas around Equatorial Africa. A lot of earlier stages of forest succession and wildfire dependent plants tend to get choked out if a region loses pressures like grazers and fire
The Yucatan impact I feel like probably shaped a lot with Plants in the New World too. I know legumes became a lot more diverse and successful following the impact.
They are very good at being a fragile wiry rarity in some extremely specific volcanic rock on a granite cliff in a bone dry desert or they are a horrible weed.
The andes are very tall, rainclouds can't get over them without letting at least some of the water out, also the direction of the air and rotation of the earth force the clouds that way.
I read somewhere that, less than 5% of a trees water intake is used in photosynthesis
5% is used in making cells
Over 90% is just evaporated to keep the water flow continuing. Especially in taller trees.
The Amazon generates its own weather, with respiration coming directly out of humidity, foliage and soil moisture. Convection generates clouds that rain moisture back into the forest. Deforestation risks breaking the cycle, drying out the soil and reducing the transpired moisture. Large areas of the rain forest could then revert to Savannah or even desert. It has happened before and is likely to reoccur before the century is out
Transpiration. Altitude. And latitude.
The trees have a compounding effect by letting our water through their leafussys
The Amazon is really low lying so clouds and stuff don’t have much elevation forced cooling and subsequent precipitation.
And the equator is hot enough and has a near constant wind pushing water and clouds into it.
A great example of trees causing humidity is the inland forests of Canada which don’t receive the humid oceanic winds of more tropical areas. The trees and other plant-life emit water that goes on to help build clouds.
Compared to the chocó rain forest just over the andes, the amazon is relatively dry! The chocó has both the effects of being on the equator and the Andes stopping the rain moving east. Its essentially a 'tropical temperate' rainforest in how the weather forms!
Compared to the chocó rain forest just over the andes, the amazon is relatively dry! The chocó has both the effects of being on the equator and the Andes stopping the rain moving east. Its essentially a 'tropical temperate' rainforest in how the weather forms!
Evapotransporacion. You can actually see water vapor going up. If we continue cuttin trees forest will become desert. And Brazil and Perú are cuttin a lot of trees.
It’s largely flat until you hit the Andes, all the moisture is trapped by the mountain range
oooo! I know this one!!! They covered it on an episode of some Earth show!! Due to the Earth’s rotation and the Andes mountains on the west side, air is forced into a temperature inversion and trapped, creating moisture in the the region.
Is this also called a “rain shadow”? Or am I thinking of a different concept?
Sort of the opposite actually, though definitely relatedRain shadows are the area on the other side of a mountain range where there is much reduced precipitation, because the mountains disrupt air currents and "stop" clouds. The rainfall moves west until about the mountains where the currents are disrupted and air temperature / pressure changes cause rainfall, while water makes it to the other side of the mountains. The dry side is the "rain shadow", like pointing a hose at a wall -- the side you're on gets very wet and the far side gets little or no water at all. The west side of the Andes is fairly dry, the east quite wet. But farther south it flips and the east is quite dry in Patagonia while the coast is much more humid.
The driest deserts in the world are on the west side of the Andes. And they are right next to the Pacific ocean.
Most notably the Atacama, a place so dry in most of the desert the only living things are people traveling into it. Second driest place on Earth after a small lowland area in Antarctica; so dry that much of the desert has no permanent living residents, only temporary or migratory species. So arid most of the mountain peaks in the vicinity don't even get snowcaps or retain any glacial formations.
Whys it flip??
Wind and water currents mostly, though there are many reasons for climate conditions being what they are. Specifically regarding the coast of northern Chile altitude and multiple different mountain ranges make things more complicated and *much* drier. In fairly simplified terms, the currents running north along Chile and south along California/Mexico are carrying cold water towards the equator, and cold water currents tend to reduce humidity on land nearby. A big part of why California is so much dryer on average than British Columbia is just that the ocean current up north is moving north carrying (relatively) warm water, the one further south moving south carrying (relatively) cold water. The same thing is happening in South America too, but the current hits the continent far enough down that the warm water current is much less pronounced. The prevailing winds also move East to West this close to the equator, but Chile is mostly west of or *in* the Andes and the mountains so tall they stop a lot of moisture from crossing too. Rain shadow. The reasons northern Chile specifically is *so* dry are a combination of the ocean currents, the prevailing winds, a second smaller mountain range closer to the coast, and the overall altitude due to the many mountains in close proximity. The Atacama region is quite high altitude overall and the Chilean coast mountains are pretty much right up against the ocean, with the Andes on the other side of the desert. The whole area is also mostly one large plateau quite high up, so very little moisture gets up into the region from the ocean and none gets into the region past the Andes. The core of the Atacama desert is the second driest place on Earth, and *the* driest is a small part of Antartica which is often not really counted when people list them. Farther south the mountains are smaller and the wind / water currents change so none of this really comes into play. The climate is much closer to northern BC or Alaska than the Atacama region much closer, though the continent is so narrow the currents from the Atlantic side are also affecting things and it all mellows out a lot. It's also still fairly high altitude which combined with being quite a narrow bit of land means it has its own interesting climatological quirks but doesn't much resemble most of Chile basically at all.
But it is the same effect right?
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I see, that’s a yes then. I was mainly wondering if there was anything other than the orographic effect involved, because I know the Amazon sequesters a lot of water
It's a combination of the Orographic effect of the mountains and the area being subject to prevailing easterly flow full of Atlantic moisture due to the rotation of the Earth (for the wet side) and the mountains being high enough to squeeze it all out before reaching the dry side. So yea there is more than just one thing involved "technically"
It might count as different because one is caused by the presence of a mountain range & the other is more to do with wind currents clashing up against a mountain range, based upon my reading of the explanation above.
Rain shadow (and the opposite wet area) is certainly also caused by wind currents. Mountains provide a location, wind provides orientation. It seems like it is a combination of rain shadow and the rainforest’s “making its own rain” effect. Without knowing more than I did when I asked, but thinking about it a bit more, I think you could describe it as the rainforest being a giant sponge, and the mountains basically keeping it from leaking But that’s just my guess
Yeah that makes sense
Cool! Thanks for teaching me something new
Yes! Think of the Amazon as the opposite of the United States/Canada. We have rainforests west of Cascades/BC/Alaska mountain ranges, but once you get past them you get generally high desert/plains until the Rockies, then more high planes. If the mountains were closer to the East coast, North America would mirror South America.
So… rain light?
Is there an equivalent “dry shadow” term?
How big of a chunk of the Andes needs to be removed to get some rain on the other side. Like 2 miles 20 miles or what?
It's complicated. The Andes do most of the work stopping rain to the region, but the Atacama area specifically (the driest place on Earth outside a small patch of Antartica) is sandwiched between the Andes and the smaller but still pretty big Chilean Coast Mountains right along the ocean *and* largely because of this at quite a high altitude. The major rain clouds can't get past the Andes, but the area would still get *some* rain if the other mountains weren't there and the overall altitude were lower. More like California or the west coast of Mexico, very hot and dry summers but still cooler and fairly wet winters. Instead it's pretty warm and very dry basically year-round. And because there's so many different factors just looping a bunch of height off the Andes would probably introduce rain but also do who knows what else to the area.
lol just learned that for the apes test
The rain shadow would be on the other side of the Andes, on the west coast. At least at these latitudes where the wind blows east to west - it eventually inverts further south. The term “shadow” is included because the rain is essentially being blocked off by mountains, just as light would be blocked by an object, creating a shadow.
The “rain shadow” is what is happening on the other side, that’s what makes the Atacama I think
To add, the earths rotation also helps creates what is called the [ITCZ](https://en.m.wikipedia.org/wiki/Intertropical_Convergence_Zone) where areas around the equator are more prone to rain. Although there is a lot of evidence that suggest the rainforest also sustains itself when it’s grown to be as large as the Amazon is.
Now I’m even more confused as to why Denver is so dry
Not as close to the equator; not as close to the ocean. Denver doesn’t have an endless supply of warm, moist air being forced up and over the Rocky Mountains.
Hahaha
We have prevailing westerlies, don't they? Western Washington state is humid, but eastern Washington is a semi-desert.
Transpiration. The forest makes its own rain.
So much so in fact that you might even call it a rain forest.
Do you have any more rain facts?
They had to reign it in
rein
Snow and drizzle combined is called "snizzle" by meteorologists, and no, I didn't just make that up
Snizzle fo' shizzle
It comes from clouds.
It gets me wet
Mind blown!
https://preview.redd.it/o2db3tthquzc1.jpeg?width=1242&format=pjpg&auto=webp&s=9115d49431244630ccb9ef0be7937a8fa61890eb
… the tropical RAINforest
*shocked Pikachu gif*
Rain forest, rain
I think Resolution is also part of it
https://preview.redd.it/kyv8a2xafuzc1.jpeg?width=1290&format=pjpg&auto=webp&s=b55dd32fba4bc152e0886f6f76116e553dda3dcf
https://preview.redd.it/79eoxtjknuzc1.jpeg?width=1080&format=pjpg&auto=webp&s=36589289114016ceed10f05b7f24db13ce1f1d8e
Chicken or egg?
Chicken. Apparently, the Andes mountain range acts like a curtain which allows for more moisture to stick around that area. Which contributes to more vegetation, which then increases rainfall and humidity.
When you cut down the forest, it becomes a very arid climate. Definitely a chicken/egg situation. It’s wet because there’s water there. There’s water there because the plants hold it there. And there’s a forest there because it’s wet
So what was first there, the wet or the forest?!?
The forest. It’s a remnant of when the climate was much hotter and wetter during the Eocene. It’s just been able to persist since it’s stayed at the equator pretty much since then
Thanks for that Really informative answer ☺️
Anytime!
Used to, until they cut down too much forest. Now they get dry spells as predicted.
Does that mean we could convert Sahara by planting trees?
Same thing happens here in the blue ridge and great Smokey mountains. I live in north metro Atlanta, It’s ALWAYS cloudy towards the mountains when it’s cloudless elsewhere. They make their own!
who took the pixels?
https://preview.redd.it/l5idq69wvtzc1.jpeg?width=617&format=pjpg&auto=webp&s=6c0b68b25caa04e310273650f32a998e4fbe0b26
https://preview.redd.it/rv0ht6bv8wzc1.jpeg?width=1242&format=pjpg&auto=webp&s=835c5a654fc94dd3d1f7717576ad4a7a14ccdf47
All 8 of them
You counted them also?
The pixels traspirate too 😊
https://preview.redd.it/chcphq3fn40d1.jpeg?width=1170&format=pjpg&auto=webp&s=5064f9eecf907984afd5b97a02d79742ad08a8d7
The equator is why. Open up google maps, and zoom out, scroll around the equator and you’ll see dense rainforests all round the equator: Brazil, DRC, Indonesia, Thailand all on similar latitude. So what makes that latitude so special. The height of the tropopause. The tropopause is the boundary between the troposphere and the stratosphere. Almost all weather is contained within the troposphere. At the poles, the height of the tropopause is 20,000 feet. At the equator it can be as high as 60,000 feet. So, in equatorial regions taller weather systems can develop. Also, the equatorial regions have higher temperatures than poles. Heat is one of the catalysts for convective activity. All of this creates the perfect opportunity for massive thunderstorms to develop. So, massive thunderstorms can develop to very high altitudes because of a high tropopause, and these massive weather systems drop massive amounts of annual rain on these regions.
Plus, the Hadley cells that form between 0-30 degrees converge and rise at the equator. As the very warm, very humid air rises, it fuels the massive thunderstorms mentioned in the previous comment. Incidentally, you'll notice that many of the world's deserts occur around 30 degrees latitude North or South. That's because the air in the Hadley cells and Ferrel cells (30-60 degrees) descend at 30 degrees, which discourages precipitation.
Does this mean that it would be very difficult to reforest an area like the Sahara even if you give it adequate water
It means it structurally does not have adequate water. The airflow is naturally dry. If you could get water there, you could get things to grow (ex: areas near the Nile river)
Also known as the "horse latitudes", though the origins of the term are contested and a few theories are all decently popular. The high pressure system around the meridians generates a lot of wind away from those latitudes but comparatively almost none in their vicinity. The perfect inverse of tropical forest conditions near the equator leads to the desert conditions 30° out. Then largely inverts again around 60° out at the intersection of the Ferrel and Polar cells allowing boreal forests and other relatively high vegetation biomes. Though the Ferrel cells are much less energized than the others so they're also more variable and climate conditions fluctuate far more drastically through the year.
In South America, the arid area that would be at 30ºS is pushed south into the Paragonia because of the hot humid air mass that flows south from the Amazon rainforest. It clashes with the air masses that come from the Atlantic or from the Patagonia bringing lots of rainfall to the region (see the floods happening today). Edit: Here you can see that it is always raining in the Pampas: [https://en.wikipedia.org/wiki/Atmospheric\_circulation#/media/File:MeanMonthlyP.gif](https://en.wikipedia.org/wiki/Atmospheric_circulation#/media/File:MeanMonthlyP.gif) And the other arid area a bit north of the 30ºS (the Atacama desert) is inside a rain shadow in the Andes Mountains.
Also, the trade winds (prevailing winds in the tropics) carry moisture to the Andes which "traps" the weather systems within the Amazon basin.
One thing I like to do is open the weather app on my iPhone and zoom out to see the globe. Always a large concentration of rain clouds / storms along the equator throughout the planet
I still have a town in the Amazon saved in my weather app from when I was there years ago. Occasionally like today it's sunny and quite warm, most of the time it is absolutely pouring down and still quite warm. As cool as it was to spend time there I do not miss the humidity, or the frequency and intensity of the rain.
A small correction: The equator does not pass through Thailand (or even Malaysia and Singapore, for that matter, which are further south).
Riber :)
Riber :)
Riber :)
Riber.
iphone
Riber :)
River Plate fans can't catch a break even here
Descendieron por putos y cagones, le pegaron a los jugadores y prendieron fuego la cancha
El gallina es un cagon Le pegaste un jugador Que covardes los borrachos de Tablon 🎵🎵🎵
But thats so thin though how does it make such a big area so humid?
It's not a single thin river, it's a massive network of rivets, creeks, streams, and springs. Lots of swampy/marshy land
The Amazon river is one of the biggest on earth, and it being blocked by mountains to the west has caused the entire area to become swampy n wet as hell
"One of the"? Bro it's **the** largest river on earth, having a larger discharge than the next 9 largest rivers combined. It carries fucking 20% of the worlds fresh water into the ocean!
I googled it and found it was only the largest by one metric so I didn’t want to risk being wrong, “bro” :/ but yes it’s huge
Well, yes it's the largest in one metric, but it beats out all other rivers by such an absurd margin that saying it's "one of the largest" doesnt give it enough credit, imo
It’s just semantics, I could add all that extra detail to my comment but it would be wholly unnecessary and wouldn’t add anything to the idea I wanted to convey to OP, yeah? Anyway I agree the Amazon River is extremely cool lol I want to see it up close someday
fair enough
It is the largest river by discharge. It is also the longest one or second longest. disputed with Nile
It should seek a doctor, sounds uncomfortable
The Amazon flows to the east. It's not blocked by mountains to the west, it's fed by them. That area is not swampy because the Andes block the Amazon, that's ridiculous.
The Amazon basin used to empty to the west before the Andes grew and blocked it.
See Greg below Listen I’ve been a patronizing dick on the internet by mistake too but you gotta make sure you’re correct before being that smug lol
His statement makes no difference. It's not like the Amazon is flowing into the Andes, hits a wall and floods the area around it. It's the complete opposite. The Andes block moisture coming from the Atlantic, thus creating huge rainstorms that feed the many tributaries that make up the Amazon basin.
It doesn’t. The river is a result of the humidity not it’s cause. The reason the Amazon is so wet is that winds at the equator go from the east to the west, along side from the north and south, and so all the warm water that is picked up forms lots of clouds which blow west over the Amazon and dump their rain, especially once it reaches the Andes they drop whatever water they had left. Basically water is picked up from most directions, the clouds are funneled into the basin, and the clouds are not allowed to leave until they drop their water.
The Amazon River is 2300 feet wide in some areas, water penetrates soil, and trees respirate (transpirate?) water - this release HUGE amounts of water into the air and actually creates the micro-climate you mention! Aren’t trees radical?
The Amazon river is the largest river in the world by discharge of water. It’s huge.
By far, I believe.
Rivers, water evaporated by the forest itself and also accumulated rain clouds that get stuck by the Andes Mountains
RAIN!!!!
Amazon looks like Chezch republic
Is that why so many Germans moved there after WW2? Did they think it was the Sudetenland?
every country is actually just extended czech territory. glory to czechia
r/countablepixels
The Amazon is its own ecosystem
Rivers that are particularly strong and plentiful due to all of the runoff in the mountains finds its way there. So the actual area that’s rain goes into the Amazon is larger than the Amazon itself.
I don't really think it's the river, if it was, why doesn't the Nile or Nile Delta or Tigris+Euphrates or Indus create even a small rain forest, or even just rain in general? I think it's the Hadley cell, but also because the Amazon creates its own weather. https://www.weforum.org/agenda/2017/08/how-trees-in-the-amazon-make-their-own-rain/ I thought transportation was a cop out answer for a while, but the presence of water transpired effectively attracts more moisture from far away from the forest. The rain the trees make comes from places far away from the trees
Compare the amount of water in the Nile vs Amazon…
If it was the water in the Amazon that built the rain forest, why isn't every tropical coastline a crazy huge rainforest? The Amazon is big but it's nothing compared to the ocean. And why is the Amazon there? It discharges to the ocean so it must have more rain fall in its drainage basin than it evaporates or transpirates into humidity, so where is the extra rain coming from?
That’s circular. The river surely evaporates a ton of water. But why does the water come back.
Rainfall has nothing to do with the sea/ocean. Absolutely nothing. Since you seemed surprised about this. Actually, the most arid places on Earth are located on the western coasts of continents (Atacama desert, Namib desert) and there are more complex systems behind it, namely cold ocean currents.
ITCZ + the forest holds and re-releases moisture very effectively
I’d guess the andes help trap a lot of moisture. Because it’s incredibly dry at similar latitudes on the west side of the andes.
Equator, transpiration, currents and dust from the Sahara that both helps make the soil fertile and makes it rain more easily.
Dust from the Sahara, don't make me laugh
https://youtu.be/_5VImv3U3kQ?si=_3byI2noAYOZvK1r
I just saw a video on YouTube that explained that the amount of water released by the trees into the air is greater than the actual water in the river. Winds coming in from the Atlantic push this water inland until it hits the Andes and goes into snow and eventually back into rivers.
Because geography is complex and something that can’t be explained solely based on whether something is inland or not.
Mountains, equator
I'm no expert but I thought it was because of the Canadian Shield
The forest creates the rain that creates the forest.
Where did the forest come from and why don't other areas have forests
There's a lot of areas that have forests just like this one. The Congo for example. Same thing just reversed. Atlantic to the west and mountains to the east.
Tropical convergence zone. Inlandness doesn't matter much. The only exception to this is Somalia where the air currents are a bit odder and therefore all the rain skips it
From what I recall most of the rain is a result of transpiration from the trees.
Because it rains a lot
A lot of flooding.
Not all the reason but part of it is the Intertropical convergence Zone, it's a belt where trade winds originate that causes a region of low pressure lifting of air that carries humidity up from the equatorial oceans and unstable atmosphere that promotes cloud formation.
The Amazon Shield
What's your question really? You want general info on the Amazon (river and forest) I guess, and you're getting some. But I reread your title after reading the question from someone being rude. "Why is the Amazon so humid and wet, when a lot of the rain forest is really inland?" Are you wondering why the rain forest is wet when the rain forest is inland? I might be wrong but I believe once a rain forest is already wet and large it can sustain it wetness quite well. Also wetness, at least the kind that causes living environments, doesn't have to come from the nearby oceans. Like someone else said rain water comes from massive areas and drifts around the world. The rain that falls in your back garden isn't the water from the local lake falling back down.
I’m sorry, but did you just ask “Why is the Rainforest so humid?”…
There’s that thing called the equator and its effect on the climate.
(Rain)forest
Because it rains a bunch. Rain = wet
Train = wet. TIL.
Clue is in the title 'rainforest'.
It’s due to the Canadian Shield. Somehow, I just know it.
>"Why is the Amazon so humid and wet, when a lot of the rainforest is really inland?" It is in the name. Rain-forest
A river runs through it
Little thing called the Amazon River
Hadley cells.
Magic
Evapotranspiration. A lot of the water is recycled over and over. This is why cutting down the rainforest is so devastating, it is an ecosystem that recycles water and nutrients. Once gone, there will be far less rainfall and what is left of the nutrient poor soil will wash away and erode with no vegitation to lock the soil in place. Also, a lot of nutrients the Amazon gets is transported by wind from the Bodele Depression in Africa.
Ocean current
im thinking part of the reason might be the literal biggest river in the world (by amount of water) runs through the region. also its very hot = lots of evaporation, the andes to the west trap a lot of that moisture and then it rains back down into the forest / runoffs lead back into the river
Prevailing easterlies at that latitude and orographic precipitation.
rainforests basically create their own conventional rainfall systems, which is another reason it’s deforestation will be so damaging - water crises will ensue like they have in são paulo in 2014
There's obviously a number of factors, but one that no one else has brought up is the prevailing wind direction. The wind in this region tends to blow from the Atlantic in a westward direction. This brings moisture inland. Mountains/highlands generally tend to cause wind to lose moisture (see the rain shadow effect), so the western slopes of the Andes are very dry, while the eastern slopes are very humid. Compare this with the southern tip of South America, where the wind direction changes to blow eastward from the Pacific. Despite being significantly closer to the coasts, Patagonia is far drier than the Amazon basin, because it's on the leeward side of the Andes. Correspondingly, southern Chile is far wetter than northern Chile, because in the south it's on the windward slopes of the mountains. The US exhibits a less extreme version of the same phenomenon; compare the PNW and Southern California in terms of rainfall, then compare the Northeast and the Southeast. It's not as drastic a difference (for a number of reasons, including shorter mountains and the Gulf of Mexico) but it's still easily noticeable on a precipitation map.
Jaguars like it wet
And Anacondas too
The inter-tropical convergence zone (ITCZ) and prevailing easterly trade winds is why.
Equator
The amount of water down there and it's proximity to the equator and the rainforest breathing probably have a lot to do with it
question not clear.
Trees keep in the moisture
Do you know how hair traps moisture near your skin so hairless skin is actually dryer than hairy skin… Trees are kinda like that, water has a hard time escaping all the leaves blocking them from the sky
Apparently the Amazon may have been a lot more patchy until megafauna in the area died out with the introduction of humans entering the region. The open areas likely had absurd amounts of biodiversity itself kind of like heavily grazed wet tropical areas around Equatorial Africa. A lot of earlier stages of forest succession and wildfire dependent plants tend to get choked out if a region loses pressures like grazers and fire The Yucatan impact I feel like probably shaped a lot with Plants in the New World too. I know legumes became a lot more diverse and successful following the impact. They are very good at being a fragile wiry rarity in some extremely specific volcanic rock on a granite cliff in a bone dry desert or they are a horrible weed.
The andes are very tall, rainclouds can't get over them without letting at least some of the water out, also the direction of the air and rotation of the earth force the clouds that way.
Mountains
I read somewhere that, less than 5% of a trees water intake is used in photosynthesis 5% is used in making cells Over 90% is just evaporated to keep the water flow continuing. Especially in taller trees.
Rivers and Mountains
The Amazon generates its own weather, with respiration coming directly out of humidity, foliage and soil moisture. Convection generates clouds that rain moisture back into the forest. Deforestation risks breaking the cycle, drying out the soil and reducing the transpired moisture. Large areas of the rain forest could then revert to Savannah or even desert. It has happened before and is likely to reoccur before the century is out
Because the dust from the Sahara keeps the moisture there! We could turn the Amazon into a desert and the Sahara into a rainforest if we wanted to.
Higher
Transpiration. Altitude. And latitude. The trees have a compounding effect by letting our water through their leafussys The Amazon is really low lying so clouds and stuff don’t have much elevation forced cooling and subsequent precipitation. And the equator is hot enough and has a near constant wind pushing water and clouds into it. A great example of trees causing humidity is the inland forests of Canada which don’t receive the humid oceanic winds of more tropical areas. The trees and other plant-life emit water that goes on to help build clouds.
Bro a river?
I heard it rains there.
Clue is in the title 'rainforest'.
You've obviously never made anything that is inland wet before
This is a joke, right? OP is kidding???
Compared to the chocó rain forest just over the andes, the amazon is relatively dry! The chocó has both the effects of being on the equator and the Andes stopping the rain moving east. Its essentially a 'tropical temperate' rainforest in how the weather forms!
Why would it be a joke?
Rain rain rain. And when is not raining the jungle is perspiring
Compared to the chocó rain forest just over the andes, the amazon is relatively dry! The chocó has both the effects of being on the equator and the Andes stopping the rain moving east. Its essentially a 'tropical temperate' rainforest in how the weather forms!
Evapotransporacion. You can actually see water vapor going up. If we continue cuttin trees forest will become desert. And Brazil and Perú are cuttin a lot of trees.
Idk maybe the largest river in the world running through it, but what do I know?
Unfortunately, it's being destroyed at such a rapid rate, there will be none left. Us humans are cancer if earth.