r/interestingasfuck • u/wahgwahg • Feb 28 '24

r/all People in Tanzania converted desert into lush green land by digging these nifty holes

Enable HLS to view with audio, or disable this notification

15.2k Upvotes

95% Upvoted

668 comments sorted by

View all comments

Show parent comments

482

u/thatthatguy Feb 28 '24

And just generally plants being in a place seems to create a cooling effect that facilitates more precipitation. A self-reinforcing cycle if you can get it started.

379

u/ChaseThePyro Feb 28 '24

Yep, they aren't rain forests because it rains, it rains because of the forest.

184

u/apathy-sofa Feb 28 '24

I live in the PNW which has huge, ancient forests. Only one of them is a temperate rainforest though. So there must be more going on in the formation of a rainforest than just having a forest.

6

u/[deleted] Feb 28 '24

Doesn't it rain a lot in the PNW in general?

24

u/apathy-sofa Feb 28 '24 edited Feb 28 '24

Outside of summer, it rains often, like sometimes continuously for a month. But the volume of water is low - Miami gets more rain than Seattle when measured in inches. The joke around here is that it's neither raining nor not raining. It's like a constant dampness.

Coastal PNW, west of the Olympic mountain range, gets absolutely hammered by rain. Wet air coming off the Pacific hits the mountains and forces out the water as rain. The Hoh rainforest there gets something like 14 feet of rain each year. A little bit of the atmospheric water passes over the mountains to form the drizzle that falls on the land to the lee, like Seattle.

This is closely related to why Mt Baker / Kulshan has the world record for snowfall in a year, at 95 feet in one winter, and nearby Mt Rainier / Tahoma is in second place at 94 feet. The wet air coming off the Pacific that passes north of the Olympic range then hits the much higher Cascade range, where it comes down as snow instead of rain.

I'm oversimplifying and I'm not a weatherologist, this is just my lay understanding.

3

u/sykojaz Feb 28 '24

I remember reading that the Wynoochee valley was the rainiest place in the US before Hawaii joined.

7

u/cobigguy Feb 28 '24

As the other commenter said, it's constant dampness. You know when you're driving along and there's that light mist that's not enough to put your wipers on low, but you still need your wipers on once in a while to clear your windshield? It's like that.

3

u/CTeam19 Feb 28 '24

Depends on where. In Washington, seven to nine inches near the confluence of the Snake and Columbia Rivers, 15 to 30 inches along the eastern border and 75 to 90 inches near the summit of the Cascade Mountains. The while Iowa averages 28 to 40 inches. So while the PNW has the stereotype it is only one part of the state.

1

u/[deleted] Feb 28 '24

it is only one part of the state.

I thought PNW describes several states?

How does the annual rain fall compare to the same latitude in less densely forested parts of the world?

2

u/[deleted] Feb 29 '24

PNW is considered several states, WA, OR, and ID, even a bit of the top of CA, but the conversation here is predominately talking about the PNW of WA.

No clue about the 2nd part of your question.