Naked Science Forum

Life Sciences => The Environment => Topic started by: clbuckle on 09/08/2009 20:36:19

Title: Can a dust devil curl a piece of ribbon on a strand of wire?
Post by: clbuckle on 09/08/2009 20:36:19
We live in the high desert in California and quite frequently experience dust devils. We are trying to grow some fruit trees, grapes, and berries, so we tied some mylar ribbon to the trees and to the wire that the grapes and berries grow on to keep the birds away. Now, the wire is attached horizontally between two pieces of wood that are in the ground. One day we noticed that the ribbon on the wire over the grapes looked like someone had curled it, like you would do to a ribbon when wrapping a gift. It was also wrapped around the wire several times and slightly knotted. Right next to it a few feet away, the ribbon on the wire over the berries was still completely straight. My husband seems to think someone went out there with scissors and curled the ribbon, but everyone says no they didn't. My thought is that a dust devil went through that area and hitting the ribbon against the wire curled and knotted it. My husband says that is impossible because the ribbon on the berries it still straight. Is it possible that a dust devil could have curled the ribbon over grapes, and not have done so to the ribbon a few feet away? If someone can clear this up for us it would be greatly appreciated.

Thank you,
clbuckle
Title: Can a dust devil curl a piece of ribbon on a strand of wire?
Post by: paul.fr on 09/08/2009 20:52:28
Welcome clbuckle.

Yes, it is entirely possible. The track width of a dust devil can be very thin indeed, even the length of the track can be very short, and IIRC can have a lifetime of just one large field. You can liken this question to the fact that it can be raining in your front yard but not in the back.

Here is a link to a PDF files you may like to read:
DUST DEVILS ON EARTH AND MARS (http://gaspra.la.asu.edu/dustdevil/proceed/Balme_and_Greeley_DD_ms.pdf)
Title: Can a dust devil curl a piece of ribbon on a strand of wire?
Post by: paul.fr on 09/08/2009 21:14:29
A quick check on Wikipedia, gives this:

Quote
A dust devil is a strong, well-formed, and relatively long-lived whirlwind, ranging from small (half a meter wide and a few meters tall) to large (over 10 meters wide and over 1000 meters tall).

So I did remember correctly!

Wiki Link (http://bit.ly/Wikidd)