Cloud of the Week #10: Altocumulus Stratiformis Undulatus

Photo by William Briscoe, Used by permssion. 

  Last week, a good friend and cloudspotter, sent me a link a website called EPOD, which stands (more or less) for Earth Science Picture of the Day--a free service of NASA's Earth Science Division and the EOS Project Science Office (at Goddard Space Flight Center) and the Universities Space Research Association. Now every day, I get a fabulous photograph from somewhere on the planet, contributed by someone on the planet with a camera. Naturally, the cloud photographs inspired me to sign up for my daily EPOD e-mail.
  Because I cannot wait to share this incredible photograph with my readers, I thought I should post it as the cloud of the week. It is a fine and likely rare image of altocumulus stratiformis undulatas. These are mid-level (alto) clumpy (cumulus) clouds. The species is stratiformis (an exetnsive horizontal layer), the variety is undulatus (cloudlets undulate in parallel lines).
  A quick note: There are 14 cloud species, which describe the shape and structure of each type of cloud. There are 9 cloud varieties, which describe either the transparency or arrangement of the cloud elements. There are 10 cloud genera. Don't bother doing the math to calculate all the possible types because a single cloud can express more than one variety (e.g.: altocumulus stratiformis perlucidus undulatus radiatus.)
  So back to the Cloud of the Week. This was posted on EPOD by William Briscoe who kindly gave me permission to post it here. The photo was taken about 8,500 ft somewhere over the southeastern California desert. Shadows from the clouds are projected on the desert sand and look like undulating dunes in the sand. Look again! The undulations are shadows of the clouds given a little extra warping by uneven topography. What's fun about this photograph is that at first glance it seems to be one taken underwater by a scuba diver.  
  Now I am curious to go snorkeling to look for cloud shadows on the floors of silent seas.  

Click here to go to EPOD's website and sign up for your own free daily glimpse of Earth not seen in your local paper.