This past week has been a week of holidays: Chinese New Year, Lincoln’s Birthday, Valentine’s Day, Presidents’ Day, Shrove Tuesday, Ash Wednesday, and Margaret’s Birthday! We’re about half way between the fist day of winter and the first day of spring. The media says it was the coldest Valentine’s Day on record. It WAS cold; we didn’t get above zero on Valentine’s Day.
Here’s the temperature on the morning after Valentine’s Day. It counts as -25, but there was no wind and that helped a lot. My parents used to count the mornings below zero so I looked through some of their records. My mother kept a journal of daily paragraphs from 1982 to 2004 with temperatures sporadically included. Surfing through a random notebook, I found a -27 with a strong wind for January 19, 1985; two days earlier the daytime high was +36! Our forecast for next week looks like it’ll make mid30s, although the turn-around time will not be not as abrupt as in 1985.
Even at the below zero temperatures, there’s melting on the south side of the house in the direct sun because it’s getting more powerful. Runoff from the dark porch roof built this stalagmite and stalactite out of ice. (There’s an old retired geology prof “joke” that says in caves its “Up go the mites and down go the tights, like ants in your pants.”) The combination of a powerful sun and cold temperatures grows some impressive ice cycles and sculptures. My folks used to quote the old saying: “As the days lengthen, the cold strengthens.”
These pictures of a sunrise and sunset were taken by Margaret. The sunrise picture is from around the time of the winter solstice, but during this cold snap the sunrise position has shifted to the north. Now it comes up behind the Greats’ old House and we don’t even see it. The sunset shows a view to the west along the Stateline just last week. By the time of the spring equinox, the sunset position will shift north until it goes down at the point where the road disappears over the horizon. Our weather calendar says there’s about 8 hours and 45 minutes of daylight around the first day of winter, about 10 hours and 20 minutes around Valentines Day, and about 12 hours and 10 minutes around the first day spring. The next batch of lengthening days will bring much warmer temperatures, I hope.
Just before the cold snap there wasn’t much snow cover so the frost depth has probably increased a lot. That could be tough on those earthworms who were busy back during our January thaw. The depth of freezing most likely varies with differences in vegetation cover. Earthworms under the bare lawn may not be as comfortable as those under the snow near the long grass. The picture on the right is in a paddock with warm season native grasses. Hopefully the worms are really happy and healthy under this tall grass where the snow is providing some insolation from the cold that’s creeping deeper.
Depth of freezing temperatures and earthworm survival may also be influenced by snow cover that’s trapped in small-scale rises and depressions. The picture on the left shows snow along a slight rise in the land surface in the Creek pasture. I wonder if the soil microbes are different under the snow when compared to the brown areas that have blown clear. The linear white snow bands in the right picture mark old cultivation furrows where potatoes were planted in the early 1900s. Even those really subtle depressions might trap enough snow to influence depth of freezing. Do micro-topographic features like these, impact the well being of the soil microbes and earthworms? Are there observable differences in soil health associated with really small changes in the landscape?
Beyond the techy soil science, there are other questions about the cold snap. Why is it so quiet? It seems like it’s really easy to hear the wind in the tall grass or an owl trying to be sociable. Maybe it’s because the cold air suppresses sound? Or, maybe it’s because there are no neighbors out driving tractors and trucks around in the frigid weather? In any case, there’s been a cold silence around the Farm “in the bleak midwinter”.