Galatians, one more thing to consider in your lesson, whatever the dew point is the reason the temps bottom out at that temp is because of the dew wet or frozen(frost), it´s forming on surfaces pointing sky is simultaneously releasing heat which causes temps from dropping below the dew point. This is why irrigation is commonly used on convection freezes. Even at the freezing point humidity in our case, the water applied releases heat back into plant. Water applied to foliage looses about 40 kj of heat for every mol, 18ml in the cases of water then if it freezes on the plant another 6.01 kj/mol keeping the temps just above many tropical own freezing point. Sorry for doing chem teacher thing but you seem to be deepening your understanding..we use to call them teachable moments.
Heat is a little tricky to understand because many people never get past temperature. But understand how heat moves helps us as growers to make good choices on ways to protect our trees and plants.
Interestingly enough, my Dad was a teacher by profession. He used to make the calculations in BTU per gallon, which seems to be a more useful measurement for irrigation systems. He also said that there was a small benefit from the change in temperature (68 down to 32), but that the majority of the benefit came from the release of latent heat during the freezing process. I have not found him to be wrong over the years.
We have used water for freeze protection even during advective freezes successfully. Advective freezes just require more water. I think the main difference is that wind causes more evaporation and heat loss. However, a good wind break helps reduce the heat loss. Thus, the hedge h planted all the way around his property. Oddly enough, hedges have been found to be more effective than solid barriers like a wall because they break the wind up instead of allowing it to roll over. UF has a handy chart about how much water you need to apply at different temperatures and wind speeds to achieve protection if someone wants to look it up and post it.