Friday, May 24, 2013

5/24/2013 New Tires and Dust Devils

(Tucson to Casa Grande and Back Again)

We were on the road to Casa Grande a little before nine this morning as we had a ten o’clock appointment at Glenn Jones Ford to have our new tires installed.

We settled into the lounge area and a conversation was started with another gentleman who was waiting for service work to be done.  One thing led to another and before you know it we find out that we lived not too far from each other back on the east coast.  He is from Havre de Grace, MD which was about 45 minutes from us.

This Ford dealership was have lunch for the public today.  Anyone who wanted to eat could stop in.  Of course since we were there anyway we took part in the lunchtime giveaway.  We had a choice of hot dogs, hamburgers, baked beans, potato salad, cookies and sodas and water.

By one o’clock we were done and stopped at the park model in Arizona City to pick something up on our way back to Tucson.

Traveling back and forth we saw lots of dust devils.


The dust devil pictured above was quite a ways away as we drove down I-10.  Dust devils come in all sizes, from small which could measure from a foot and a half wide by twelve feet high to a much larger one which could measure thirty feet wide to three thousand feet high.


Usually harmless, these well formed, usually long lived whirlwinds can on rare occasions grow large enough to cause damage to both people, pets and property.  Rare occasions are the operative words here.  An injury from a dust devil is reported once in a five to ten year span.  Of course there are exceptions, parachutists under canopy and small aircraft have to be particularly aware.  This area is known for skydiving too.


Dust devils form when hot air near the surface rises quickly through a small pocket of cooler, low- pressure air above it. If conditions are just right, the air may begin to rotate. As the air rapidly rises, the column of hot air is stretched vertically, thereby moving mass closer to the axis of rotation, which causes intensification of the spinning effect by conservation of angular momentum.  Now I didn’t really know what I just wrote, I confess, I looked it up.  If the truth be known I don’t have a clue what conservation of angular momentum is!  I just know I’m somewhat fascinated by dust devils.  I don’t even know why, its nothing but dirt and debris caught up in a whirlwind.


Did you know that dust devils aren’t only found on earth?  Nope, I didn’t either.  Actually this is something I have never given thought to but in reading up on these dusty whirlwinds I learned that dust devils have also been found on Mars.  Who knew?

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