National Geographic -- Twisted Sunday

[Dave Ewoldt]

Thanks for that info Tim. I figured I was over simplifying my views to a degree there. I hope there will be rewards for the efforts.

Ah, Yule - bring back the sun!

 

[Karen Politte]

Hey Tim,

Good to see you in on this thread. I'd figured you would be! :wink:

I hope you didn't get me wrong......I wasn't meaning to say that I'm disinterested in your work or the immense effort you put into placing probes in tornadoes. What you are doing these days as far as in-situ probe placement is certainly one of the most important advances of our time as far as finding out just what goes on in there!

That said.......I guess it's also down to what you (or I, or anyone) personally find important as far as advancing our studies of tornadoes and tornadogenesis. I know a smidgeon of what tornadogenesis involves, and even less about the intricate dynamics of tornadoes themselves, and I certainly can't lock horns with most on here when you get down to the "technical stuff".

I myself feel that perhaps the most important thing we are doing to understand tornadoes and tornadogenesis is the dual-doppler data being collected from the DOWs and Wurman, et. al.
I guess I need to be explained to. I mean - getting a probe into a tornado is no mean feat and it is mind-blowing to think that we can measure many of the variables that exist within these vortices. However - what does that REALLY tell us?? Again - we're getting back to my lack of understanding, I guess. I don't understand how to extrapolate wind speed from a pressure reading, etc. etc. But - even if I did - what does measuring the actual environment inside a tornado tell us about these beasts that's new? I'd really like to know - truthfully. How does it help us understand how they FORM? I'm not really that bothered whether the wind speeds are 102mph or 402mph. The tornado's there and it has already formed. The storm has already spawned it.

And that gets me to what *I'm* interested in - how tornadoes form in the first place and can we possibly predict to any degree with accuracy how violent a tornado any particular storm may form. This has repercussions for the warning system, forecasting, emergency management, and a whole host of other involved parties. Obviously - when I have these interests - it's easy to see why I gravitate towards the DOW research that is being done. I simply can't get enough of seeing the high-res, dual-doppler renditions of tornadic supercells that Wurman or Bluestein come home with.

But then.........I also can't get enough of the stupendous video that you came home with from Iowa in 2004, for instance. I think I'm torn! :?

Interesting discussion. I just wanted to apease and re-assess my stance before frowns started to appear.....
:lol:

KR

 

[Andrew Khan]

More than likely, the view from a sterotypical tornado's base upward will not be clear, and will be quite distorted. And thus result in a horrible picture, after risking your life. IF you get a completely erect tornado with a perfectly equal base and funnel, then perhaps you will have some success.

 

[Jayson Prentice]

I enjoyed all of the shows last night, it was the first time I was able to see Tim's show on tv. Tim your segment I believe was by far the most scientific and it left a lot of questions that still need to be answered, especially from the viewpoint of the ISU tornado simulator and what that can be used for in the engineering of structures. I think the show leaving those questions was a good thing, it shows everybody that there still is A LOT of research left to do in all aspects of the tornado. I know some of the posts said talked about how they were interested in how the tornado forms, not just once it is on the ground. But, I think even knowing more of what is occuring while the tornado is already formed will give way to a lot of information on what to look for in signs of 'tornadogenisis'. And it is hard enough already to get on a storm that is tornadic and to get setup with the DOWS and other research vehicles, I think the pressure of choosing a storm that hasn't already produced a tornado and getting information as it does would add on tremedously to the work that has to be done. I know that I'm not great on all of the aspects of this, but that is my opinion on it.

As for some of the others, the TIV was something that is interesting in several ways. First off, the way I interpreted it was that he went ahead and built this thing, not even truely 'engineering' it to withstand a certain amount of wind speed or anything else of the sorts. To add on to it, they showed his welding skills and that is a lil' scary becuase those welds do not look good at all. I'm sure they are good enough to hold it together and as he said you can go over them again, but if you are talking about a life threatening project wouldn't you want some top notch engineering on it. I guess I'm also surprised that he would have funding through the government and help from other governement research people without being a true scientist in the sense of what the others are. Nothing at all against the government projects as all of those are great projects and are going to prove to be extremely helpful in all senses of tornado research. I was just surprised that an 'film producer' and self proclaimed 'storm enthusiast' would be able to go out and get that sort of help. Maybe it was different in the way it went, that is just what I interpreted from the show.

Overall it was a good night of tv for me and I'm glad I finally got to see Tim's show. I love the video from the Webb, IA tornado beings that is my good ol' territory up here in northwest Iowa.

 

[Tim Samaras]

Karen, you wrote:

However - what does that REALLY tell us?? Again - we're getting back to my lack of understanding, I guess. I don't understand how to extrapolate wind speed from a pressure reading, etc. etc. But - even if I did - what does measuring the actual environment inside a tornado tell us about these beasts that's new? I'd really like to know - truthfully. How does it help us understand how they FORM? I'm not really that bothered whether the wind speeds are 102mph or 402mph. The tornado's there and it has already formed. The storm has already spawned it.

Yikes! Well, to start with, the things that turtles measure will NOT tell us much about how a torando forms(yea..you gotta watch those torandos!). Indeed, I can probably dig up some publication that could link tornado dynamics with genesis, but that's not my interests.

There are several websites that describe the pressure to windspeed conversion, i.e. cyclostrophic balance, etc..

http://www.cartage.org.lb/en/themes/Scienc...clostrophic.htm

There's a bunch of others, but I'm too lazy.

Certainly you may not be bothered if its 102 mph or 402 mph, but there are quite a few scientists who are very interested. Why?

*Relationship between observed winds and structural damage.

*Is the standard conceptual model of tornado structure correct? What is the depth of the tornado inflow layer? Does the structure of the tornado depend as predicted on the swirl ratio? What dynamical and thermodynamical structures affect the swirl ration? Does the behavior of any multiple vortices conform to predictions?

(Source--again the Scientific Program Overview document for VORTEX-II)

In a nutshell, there is considerable interest from a wind engineering perspective. If we can help validate models with actual data, then some good engineering can be applied to the construction of buildings, etc.

Yes, indeed we know there is a pressure drop and a bunch of wind in tornadoes, but to have accurate data--better yet---with time corrolated mobile radar would be invaluable.

Mobile radars have extreme difficulty capturing data near the ground..the lowest 10 meters. This is where the biggest mystery is. As Glen described, we don't know a whole lot how ground friction complicates the flow(a few things we may never know).

This is not to detract from tornado genesis. Its a fun and challenging problem. The turtles won't solve it.



A fellow co-worker brought in his new toy. It's some sort of "MaxTrax" thingie...a four-wheel drive electric jeep toy that REALLY moves along...

It's giving me an idea........

Thanks, all for the kind comments from folks!


Tim

 

[Glen Romine]

Yeah Tim, you just need to be able to have wheels pop out of the bottom of your turtles and an ability to get a live view from one of the cameras back to a computer where you could drive it from - then make those last second adjustments before 'sitting' down the probe.

As far as the tornadogensis information coming from the DOW's, while I wouldn't try to detract from the value of the data they offer, there are potentially better techniques to using that data than the dual Doppler methods now popularly employed (only a small portion of the storm is typically encased within the dual Doppler lobe, and a number of questionable assumptions must be used within the lobe that are probably not always appropriate), and new techniques combining other types of data with the DOW observations could substantially advance our understanding of the storm-scale processes that lead to tornadogenesis. Probably ~3-5 years from now before you'll see much on it publicly, but it's more a question of when than if given current progress.

Glen