Giant Atmospheric Waves Filmed Over Iowa

NJChopperMan writes "For all those of you that thought waves only existed in the ocean, Photos and video of undular bore waves were caught in Iowa last week." The story also touches on the role of undular bores in severe weather, but it's definitely second fiddle to the video of the waves.

Comments

Woohoo, let's go gliding!

[6Yankee]

TFA was pretty light on detail, but these look like a completely different animal from the (warning: gratuitous Wikipedia link) mountain waves so beloved of glider pilots. Wonder if they're soarable?

Re:Woohoo, let's go gliding!

[LiquidCoooled]

I would imagine if you could get up there you could surf them.
There is a really interesting article about people surfing one such wave (called morning glory!) in Australia:

http://www.williamolive.com/soliton/al-giles-original-morning-glory-article.html

One of the images inside is particularly striking:

http://www.williamolive.com/soliton/PK%20on%20roll%20cloud.jpg

Really nice images!

[muecksteiner]

Atmosperic wave phenomena have been known for ages, and are hardly inconspicious in those places where they regularly form.

The main "customers" for them are probably glider pilots; as far as I remember, all recent altitude records for soaring have been made using waves formed in mountain regions (14+km), and the current distance record by Klaus Ohlmann (insane 3000+km in one day) was also flown in the waves over the Andes. Thermal updrafts are toys by comparison.

The one thing that you have to hand to the NASA guys is that they indeed caught some very fine specimens there, and in an unusual place, too. Normally, waves are induced by the flow of wind over a given, usually hilly, terrain. Gravity waves from thunderstorm activity are certainly a lot more esoteric, and what they are saying about them being catalysts for storms sounds really intriguing.

A.

I flew my hang glider on one.

[scorpio_boy]

Seriously, go see the photos and video on my blog if you don't believe me at http://rolf.id.au/ We call the resulting visual cloud a morning glory in Australia....

Re:atmospheric waves

[tygerstripes]

More interesting are the waves set up by the harmonics of the Atlantic Ocean. There's a particular length (I forget exactly, but it's something close to 100 metres) that nautical engineers will never, ever build their ships to be, because they would get torn apart in the middle of the Atlantic by the simple harmonic motion of these waves.

Storms also "breath".

[TapeCutter]

I've been a casual cloud/storm nerd for decades and if you watch the sky long enough you can't help but notice "waves" and "drainpipes" at a more localized scale (particularly when a strong cold front is approaching).

I currently live a 100M or so from the beach in Melbourne Australia. Small intense storms come in over the bay heading directly toward the beach so you get the front "ledge" of the storm cloud coming over while behind you is clear and the drama is still out in the bay. If you stay still and face toward one of these storms roughly when the cloud/sky boundry is directly over the beach you will feel the wind do a 180deg flip as if the storm is enhaling warm air and exhaling cold with a slight pause in between. It is more pronounced with slow moving storms and can last for 15 minutes or so with a regular inhale/exhale cycle of about a minute. The first exhale of an intense summer storm can feel like someone opened a fridge door if you have been sitting with your back turned and not seen it approaching.

If rain/hail is heavy enough in the center of the storm you might also see prominent ridges running up the underside of the ledge similar to those in TFA but curved to fit the squashed drainpipe shape of the storm. When the rain/hail gets closer the wind will turn steady and cold (time to go inside).

Disclaimer: Don't try observing it standing on the beach, and escpecially not with an umbrella!

Re:Storms also "breath".

[ackthpt]

Nice post, what's it doing here? ;-)

When I was about 13 a friend and I rode our bicycles (the big old heavy steel ones of yor) about a mile away from home to purchase some candy and likely the latest issue of MAD. It was a typical hot and humid Summer day. On the way home we felt the wind pick up, kicking up dust and leaves and looked northward. Like a great steam locomotive out of the north a massive grey bank of thunderheads (large nimbus clouds with flared and flattened tops) was sweeping down. As it bore down, the front appeared to be ploughing smaller cumulous clouds before it like waves of pondscum. The face of the front was concave and decidedly dark and voluminous as it approached. The wind was practically a roar by the time I reached my parents house, struck by large early drops of rain as I sprinted across the lawn and up to the porch. It turned out to be one of the more violent in my memory.