Some background, the front of my house faces due South. And there is a big pine tree on the SW corner of my house (NW corner of the front yard). No other trees are in the yard aside from a very small redbud. There is a gentle consistent grade from my house (Higher) to the road (lower)
Earlier this week we got a small snowstorm that dumped about 3 inches of snow. It was a very ‘dry’ snow as I used a broom to ‘shovel’ the driveway. It got very cold after the snow, so I figured what was on the ground would turn icy and would not melt away until we had a thaw. It has been very cold since the snow storm, but it is warming up a little bit today
Looking out in my front yard, the snow on the entire west side of my yard is almost all gone, while the rest of the yard is still cover with snow. It receives no more sunshine than the rest of my yard. The only difference is the big pine tree at the northwest part of the yard.
Is that big pine tree reflecting that much more heat to see this big a difference in snow melt or is it some other phenomena. (I don’t think it is bird droppings from birds roosting in the tree).
Sublimation could be part of the answer. If the air is dry, even if it’s really cold, some of the ice crystals will go directly from the solid to the gas state and vanish from sight.
Quite possibly. Google “microclimate”. A tree with dark bark and dark green leaves will absorb a lot more sunlight, and radiate heat to the surroundings, while the flat lawn covered in white snow will reflect most of that energy back into the sky. That means the area around the tree will melt off much faster. Since it sounds like you didn’t have a very deep layer of snow to begin with, there was a lot less to melt.
Seeing much faster melting around trees is a common effect around here. When the snow gets deeper, you will usually see a “well” formed around each tree, where snow has started to melt back in-between snowfalls, and in spring, the melt usually spreads out from such areas.
You can also see the same effect on south-facing brick walls.
Doing a search in Google, I find several pages that say pine needles (or evergreens in general) have leaves with a certain amount of antifreeze in them so that the leaves aren’t damaged by snow or cold weather. These chemicals are normally inside the needles, but perhaps decomposing needles on the ground have released enough of this to melt some of the snow that fell on top of them?
Other than that, I would favor a theory that there was just less snow on that side of the yard to begin with. The difference between 2 inches of snow and 3 inches isn’t that obvious when it is fresh-fallen, but stands out quite significantly after 2 inches has melted away.
It’s the frostfree feature of freezers that does this. Periodically, a heater comes on in the freezer compartment that sublimates away any frost that’s started build up on the walls. It also sublimates a little bit of the icecubes. The icecubes will completely disappear if left in there long enough.