How to Create Aurora (vertically stretched)

[Elliot5FD2]

Hello everyone, 

I have been trying to create northern lights just like in the attached image. Though I have watched many youtube tutorials and looked in the forums, couldn't exactly manage to find a tutorial that explains how to draw this kind of northern lights.

Do you have any tips for me? How can I draw such auroras?

[Elliot5FD2]

For those who doesn't want to download the image: https://ibb.co/qDLK4Wk

[c.pfaffenbichler · Accepted solution]

Displace (with appropriate Displacement Maps) and Motion Blur on a Gradient might provide a start. 

Then a free transformation …