Reason for this behavior?

First of all, sorry about the poor lighting in the video, it’s winter. My dog, a Japanese Spitz, 17 month old, does this every time we’re on a walk. It’s not that I’m overly worried about him, I’m just very curious about why he does this. Leave his scent? Everywhere? For 5 minutes?

Doesn’t matter what season it is, he does it in grass, sand, ice, snow, you name it. He finds a spot and roll around, sometimes he chooses a spot so he can push himself downhill.

So far he never “targeted” something obviously smelly, dirty or dead.

We live in Stockholm, Sweden and he’s extremely social and has more dog friends than I can count in our neighborhood.