Tuesday, January 04, 2011

Frozen Winds

A couple of weeks ago I blogged about a localized whirlwind outside of the Rutgers Engineering Building.  Additionally, as I am sure you are all aware we had a big snowstorm last week.  I happened to be in the engineering building a couple of days after the storm which, as those of you who experienced it know, was very windy.  I decided to take a look to see what the corner had to show for itself.

This view is from a different angle from those I took before.  However, due to the dust in the wind we have an excellent view of the contours of the eroded snow.

This close in you can really see the contours in the snow.  Additionally, you can see where the airflow drastically slowed down or stopped from the increased deposition of dirt particles; darker means slower.

I step closer and you can see the power of wind.  If you see rock in a similar formation it was eroded by wind and water.  On the left side of this image is the outer edge of the whirlwind and you can see the concave indention into the snow from the spinning wind.  This was only a few days after the snowstorm so there was still plenty of snow on the ground, but not in the region of the whirlwind.

Now one step closer.  You can really see the streamlines of the airflow across the snow.  These are the distinct tracks of dirt in the snow which is a relativity accurate visualization of the winds velocity field.  

I would recommend you actually click on the pictures to see them in all their glory.  I wanted the images big for the drive by viewer, but as a result they are somewhat cropped.


  1. First - I would think that the low frequency variation in dirt density would be because of more snow melting (the dirt does not melt!)

    To prove this it seems that air/heat waves from the open door have melted away much snow near the tree leaving behind lots of dirt.

    Also - you may want to see my study on the aerodynamics of cars through snow from Boston.link

  2. Yeah, I am not so sure, either. It requires more study.

  3. I think Aryeh might be right, but possibly for the wrong reasons. I agree with Yoni that the dirt concentration is proportion to meltage, but I think the meltage might be proportional to wind blowing.