OK, I went and did a google for "freeze protection orchard grove" and
found a nice paper (http://www.smallfruits.org/Weather/frost_freeze.htm)
by The Southern Region Small Fruit Consortium that describes technology
and principles very well...

They also define the "advective freezing" and I see it is simply the
movement of sub-freezing temperatures into the area en masse...under
those circumstances there isn't much one can do. That's a nomenclature
not known to me previously and, as I thought, a semantics issue....we
weren't discussing the same thing.