I didn't read anything about the technique, but it's an interesting effect. The exposure is basically the same throughout the image, but the left is crisp and clean, and the right gradually moves to a faded nighttime scene, complete with long exposure fuzziness.
The purist in me doesn't like the airplane contrail, but it does add interest to the image, so I think it's a net positive.
How do you merge 30 frames? I very much like the result. I'm on the "like the line in the sky" side. I like how something like that has both fans and detractors, too.
Clouds in California - how eventful and you were out to capture them. I wish we would get tons more. Lovely softness and tranquility to this. However I agree with Hajeka about the jet line as it disrupts the mood of the image for me.
Thanks for the link to that photographer. Enjoyed browsing her work.