Here Comes the Sun

January 11, 2023 – Priddis, Alberta

Here comes the sun, doo-doo-doo-doo
Here comes the sun, and I say
It’s alright

Here Comes the Sun – The Beatles

A friend and I go for a hike most Wednesday mornings. We meet in Priddis around sunrise (in the winter) and cover about 8km. It has become a ritual I look forward to.

Before we head out, I always check the weather forecast to determine how many layers I need to wear. It isn’t very cold today so a toque, gloves, and a light jacket will do.

But, like almost every Alberta Foothills forecast, the temperature is predicted to drop 1-2 degrees after the sun comes up.

Until today, I never had an explanation for this counterintuitive phenomenon. I had a few minutes to kill before I headed out, so I Googled; “why does the temperature drop at sunrise?”.

Two completely different answers popped up:

Iowa Weather Lab: Solar radiation at sunrise is very weak, often weaker than the radiation leaving the earth’s surface. It is not until the sun gets higher in the sky that the solar radiation outweighs the exiting radiation, and the temperature begins to rise.

and:

Reno Meteorologist, Mike Alger: Once the sun comes up, the sunlight excites the cold air in the first foot or so above the ground (which can be 10 or more degrees colder), which causes it to move around and mix into the next several feet of air. That “mixing upward” drops the temperature of the air at thermometer level.

I am not sure which of these theories is correct. Either way I gotta go, …

… Here Comes the Sun

https://youtu.be/TmBTYK7XZQk

Here Comes the Sun – The Beatles