Winter solstice — 8 hours, 54 minutes of daylight

The shortest day in the northern hemisphere, the official beginning of winter.  Here’s what the backyard looked like at Noon today (the supposed high point of the sun).

Noon, on 12-21 at 45 degrees N latitude

Noon, on 12-21 at 45 degrees N latitude

As you can see, the sun doesn’t make it above the trees in the neighbor’s backyard, so there is little sunlight illuminating anything in the backyard.  I wondered what the maximum height of the sun was above the horizon at this time of year at our 45 degree north latitude, so I went looking on the web for a way to calculate it.

To do that you need the “noon sun angle equation” which is simply 90 degrees – the distance in degrees from where you are to where the sun is directly overhead.  In this case, the sun is directly overhead today at 23.5 degrees South ( the Tropic of Capricorn).  So 90- (45 + 23.5) = 21.5 degrees above the horizon!!  Wow, I knew it was low in the sky, but that is really low.  No wonder there is so little solar (heat) radiation coming this direction.

But winter solstice in this hemisphere is summer solstice down south, where the world is still green and flowers are blooming.  Looking at a world map, it is clear there are very few spots on dry land at 45 S appreciating their longest day today.  In fact, there is very little land at 45 S at all.  But I do have photos of what it might look like at 45 S at Puerto Chacobuco on the Chilean coast and Coyhaique (pronounced coy-yak’-ee), a small town inland from the port.  (Which is more interesting to look at than snow bound Minnesota right now)

Coastal mountains in Puerto Chacobuco, Chile, 45.4 degrees S latitude

Coastal mountains in Puerto Chacobuco, Chile, 45.4 degrees S latitude

Scenic drive east from Puerto Chacobuco to Coyhaique, Chile

Scenic drive east from Puerto Chacobuco to Coyhaique, Chile

farmland on the plateau in Coyhaique, Chile

Farmland on the plateau in Coyhaique, Chile. 45.5 degrees south latitude

The Chilean coast is an interesting and beautiful place to visit, especially during a northern hemisphere winter.

8 thoughts on “Winter solstice — 8 hours, 54 minutes of daylight

  1. Pingback: Swan River | Back Yard Biology

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