How High the Cloud?

My very own "glory." (All photos by The Accidental Naturalist.)
         Lucky, I got my window seat on a recent  Southwest flight to the East Coast. This time I was way forward of the wing in the bulk-head seats, which provide lots of leg room and no wing or engine to get in the way of my view of the clouds. It was an early morning flight and I sat on the left side of the plane. This was an unplanned but inspired choice because it meant I would be facing north, with the southern-arcing sun lighting up the clouds and landscape and casting the shadow of the plane onto the clouds.
    This meant that I had the possibility of photographing that optical, cloud-related phenomenon called a "glory." I wrote about this is a previous blog where you'll find the full explanation, a diagram, and a few photos that are not my own. I felt bad about the photos, but I never thought I'd capture one of these beauties myself. Now I have. Tip: If you fly eastward in the morning, sit on the left.
   I was fascinated by these clouds on our way into Chicago. They look like furrowed fields, but are clouds lined up in an undulating formation referred to as "cloud streets." The rows line up parallel to the wind and are created by spiraling air flow produced by a combination of convection and wind.
   I am 51 percent sure these are cumulus clouds, though higher altocumulus clouds also line themselves into neat rows like this. I tried to find a photograph of clouds similar to this one, but failed. So, how to make the call? I resort to some guess-timating based on altitude. Because I was taking these photographs, I knew we were above 10,000 feet. Why? At 10,000 feet, Southwest Airlines requires electronic devices to be turned off.
  Cumulus clouds typically form between 2,000-3,000 feet and I was definitely looking down on these clouds. But were they 8,000-9,000 feet below the plane? Hmmm. The other option was the higher altocumulus clouds, which typically form between 6,500 and 23,000 feet. Hmmm. These would be pretty low altocumulus clouds. I didn't see any clouds below these--an altitude-betraying cumulus, for instance.
   I was tempted to ask the stewardess to make an announcement: "Is there a meteorologist on the plane? We have an emergency."
   I kept taking photographs for a full hour after this photo above--and we were still looking down on these clouds as we descended into Midway Airport. I took this photo:  
   Help! Help! Help! Cumulus? Altocumulus? Something else? Stayed tuned.