Cowl Vent Leak?

I've got leak around the raised circular piece of metal that attaches to the upper part of the cowl vent holes that are supposed to prevent water from leaking into the car. It's right above the vent boxes on both sides. It looks like some of the old sealer has dried up and broken off. What would be good seal this up? Rtv, seam sealer, caulking?

This isn't my car, but I found this picture of the area I'm talking about. It looks as though the raised ridge is just spot welded and seam sealed. Never mind the pin holes. Mine doesn't have the rust issues. Just an annoying leaky seam. What should I seal it with?