It’s pushing late autumn, early winter, the sun in the northern hemisphere has shifted its rise and set to more southern latitudes, days have given way to night, darkness is in the majority. The sun packs an energy punch, especially when farm fields are freshly harvested, and the dark soils shown, energy transferred as heat to the ground. Then those warm soils dissipate into the nearby air via convection, keeping the air temperatures moderate. At some point, however, it snows, the lands are whitened, and sun power is reflected away without air warming. Alberta clippers blow in from the northwest, cooling via evaporation both the snowpack, or any soils peeking through, as well as the tops of any bodies of water, such as a docile lake. That lake top water cools, considers freezing, and at some point its temperature drops to four degree celsius, a temperature where liquid water has some god given characteristic of being as heavy as it can ever be. Each bit of that four degree water, being heavier than any of its non four degree neighbors sinks, and in unison stirring up the water top. The convective winds continue to blow away heat from the lake top, more four degree waters fall deeper, until eventually, in an annual dance, the bottom depths are coated with heavy four degree water, the catfish thankful for a “warm” space to hunker down to bottom feed. In that dance, the top layers of water ice over, thinly at first, sometimes uncertain on whether to thicken, but as we all know in the northern hinterland, the lake freezes thick as winter’s convections, conductions, and reduced radiations throttle spring’s eventual return.