Power Steering FLuid Foam

[Alpha D]

The problem is exactly as the title states. With the somewhat extreme drop in temperatures. I discovered a new problem on my car. As well as on a fellow member on this forum.

What happens is on initial start up. After about 30seconds of idle i observed the power steering fluid reservoir foaming up. I did not get a chance to take a picture. it literally foamed and dripped to the bottom of the car. The cap was tightly closed as well.

I did some research but was not able to find any satisfying answers. A few people believe it is due to a bad powersteering pump. Yet if that was the case how come it doesn't not do it frequently like every time. Or during warmer temperatures?

Any ideas or problem solving advice is appreciated.