Thanks for the comments, guys, much appreciated.
Larry I looked at a 1x2 AR with sky about 1/4 of what it is in the OP; it didn't ring my chimes; and I remember the sky, dust and smoke adding to the color and so I broke the rule of thirds to keep the horizon in the middle, hopefully reflecting our tension at waiting for the sunrise. I will have to see if there is a different frame in which I could emphasize the landscape layering some more.
Francois, thanks, I passed over this image years ago, but it seems my tastes have changed in seven years