This piece has a nice magical mood, very eye catching. The ray is beautifully done as well as the ice floes on the water. I think the glow and details of the ray really depict a magic winter spirit.
Regarding the water, the waves should be bigger below and smaller above since at distance things get smaller. As for the aurora, it should be a transparent thing. I also think would be good to learn composition to better place things on the canvas.
Hope this helps.