Underwater tornado

[Bill Hark]

I wasn't sure if this is an appropriate post for this section or bar and grill. I found this unusual video of an underwater vortex near Aruba. I am not a fluid dynamics engineer but I suspect some of the same processes as with a dust devil (replace air with water for current direction and differential heating.) Any thoughts?

http://www.youtube.com/watch?v=TenvpcI2HUE

Bill Hark

 

[Greg Blumberg]

That's a strange thing. I've never seen that before.

The only problem with the dust devil theory is that the temperature is stratified differently in the ocean than the atmosphere.. Heating the surface of the ocean bottom would be much more difficult to pull off compared to heating of the surface of the atmospheric bottom because of the higher heat capacity of water compared to land.

I would think that the rock showed in the movie could play a factor in vorticity generation for this phenomena. The shadow caused by the rock (or boulder) should create a temperature contrast that could help provide both the differential heating and baroclinic vorticity. It would be a similar concept to the shadow of the supercell's anvil providing an additional source of vorticity. The shadow here would create a circulation.

 

[N Parker]

That is the coolest thing ive seen in awhile!

Like the "chaser convergence" behind it...wonder if there is a "Reed fish" back there screaming "BACK THE F UP!!" ?

 

[Marcus Hicks]

The craze for next year. Chaser Subs

 

[Tim Marquis]

Looking at this video closely, I agree with greg that I think the rock is the reason for the circulation but for a different reason. I think there is a faster current coming off the top of the rock where underneath the water isn't moving. The faster water when it crests the top of the rock curls down towards the slower water generating some sort of horizontal vorticity. How this is then tilted, i assume it has to do with the rock formation. Notice how the upper edge jets out farther than the lower half of the rock. This would cause that faster water to not only curl downward but under, perhaps tilting the column. Notice how its rotating clockwise too instead of CCW.

 

[Jason Foster]

Son of a B***h....now you are telling me I need to buy scuba gear!

 

[cdcollura]

Good day all,

I assume the main cause of this phenomina is some "shear" created by ocean / tidal currents interacting with rocks / undersea formations (looks like a wreck dive in this video).

I wonder if the sea floor in such shallow water can be heated (even a half a degree or so) by the sun, so it's warmer than the water column just above it ... If that's the case, convection can play a role, just as it does with a dust devil on land.

Water is a much denser fluid than air, so the speeds involved are far less. You should still get "boundaries" of different water densities meeting, as with air mass fronts on land. Even differences in water salility can play a role in this (is the video near a mouth of a fresh water river, by any chance)?

Thanks for posting, very interesting!

 

[Ryan Wichman]

I wonder when the damage survey will come out...

 

[Karen St John]

I noticed a convergence of fish all around the vortex...

 

[Andy Jackson]

cool find

That is one of the coolest things I've seen.

On a semi-related note I remember hearing a story about a close encounter in a whirlpool once.

Here's an interesting article:
whirlpools

 

[Jason Foster]

Too bad Fujita was around for that vid. He'd really liked it.

 

[Jason Boggs]

It's really no big deal...it's just your typical water spout! LOL

Seriously, it is pretty darn cool!

 

[Bart_Comstock]

I'm a rescue diver and now I know what I will be doing in my dry land off season...
...hunting for underwater tubes! Time to go dust off my BCD and squid. LOL

 

[Scott Nelson]

Damage rated as EF-H21 (Upgraded from EF-H20)

Really cool. Thanks for posting.

 

[Scott Nelson]

Rewatched with my son and he was quick to spot storm chaser "Reed Swimmer" close by.