Pole Weather Question

[Idan]

I’ve had this question for a bit of time now, and can’t seem to find an answer anywhere so I thought I’d throw it onto this board to see what happens.

Question: if The Pole doesn’t have daily sun cycle (sun up, sun down) why does it have a temperature high/low cycle? I understand that wind & humidity have a major effect on the temperature and weather but without the regulation of the sun I would expect the cycle to be more erratic than it is.

(does this question make any sense?)

[spidey]

The angle of the sun will be the variable. Higher in the sky, more heat.
Right in the middle of the daylight season when the angle fluctuates the least is when the temp will vary the least.
But of course other factors come into play too.

[Idan]

That’s exactly the question. At the Pole the sun spirals around the sky instead of going “up and down”. So it is basically at the same elevation each day, all day.

I’m perplexed.

[spidey]

Sorry, meant to be more clear. Night and Day are replaced with higher and lower in the sky, though its still always daylight. So at midnight the angle is the lowest, at noon its the highest.

[Idan]

But that’s just it. At Pole the Sun barely changes elevation throughout the day. That’s why “sunset” and “sunrise” last forever and they have weeks of twilight before and after.

[AGE Dave]

Spidey is right.

The sun does change angle during it’s daily circle. This is the result if the earth’s axial angle of 23.5 degrees, orbital direction and the 24 hour rotation of the earth. During Austral high summer, to an untrained eye, the sun at Pole appears to not change much because the sun is orbiting almost directly overhead. At other day times of the year the angular change is more noticeable and the temperature fluctuations are greater over a 24 hour period. At “midnight” the sun is lower and at “noon” the sun is highest.

David

[Idan]

I guess I’ll just have to get there to see for myself…

[Sciencetech]

Uh, no.

At the pole, the sun is pretty much at a constant angle throughout each ‘day’. As the seasons progress it slowly rises and falls, but there is no significant difference during a 24 hour period.

Differences in temperature are usually due to changes in wind and weather fronts, much of it originating near the coast.

Farther from the pole, near McMurdo for instance, there is enough of a diurnal change to cause temperature spikes.

[Idan]

@Sciencetech wrote:

At the pole, the sun is pretty much at a constant angle throughout each ‘day’. As the seasons progress it slowly rises and falls, but there is no significant difference during a 24 hour period.

That’s what I thought, and is the origin of my question.

[AGE Dave]

I stand corrected about the fluctuations at pole…I had a long talk with astronomer friend. The sun’s angle at pole effectively does not vary over a 24 hour period.

There is just the seasonal altitude progression from horizon to zenith and back to horizon. It is, however, the daily angular change that increases as one heads north away from the pole, that set up the differences in temperature and barometric pressure and this change in temperature and pressure becomes wind…….and weather fronts.

Sciencetech…..you’re the man!

David

[spidey]

Thanks for the correction Sciencetech!
Time for me to go back to school.
Wonder how much impact leaving the door open at South Pole Station has on this as well.

[thepooles98]

Weather plays a big part all over. In the winter with no sun, you might expect the temps to be constant but they are not. In McMurdo they can go from 40 below to 5 or 10 above pretty quickly depending on where the winds are blowing from. The meteorologist told it to me this way. The Pole sits on an almost two mile high shelf of ice. Without anything else, it’s a little like climbing a high mountain, it’s just colder up high. In absence of any other weather fronts or conditions, a cold dense layer of air builds over the pole and is held in place there as an inversion by outlying warmer air. Once it gets large enough or if some other atmospheric force works on it, the mass of cold air starts to displace the warmer air and flow downhill, creating katabatic winds. They concentrate in canyons at the coast and can blow up to a hundred miles an hour. McMurdo sits just to the side of one one of these flows. The winds compress and heat up as they go downhill, but not in a way you can tell. 60 below to 40 below doesn’t mean much when the winds are blowing at forty knots. Anyway, without any other fronts coming in, this natural flow of cold air building up and then flowing downhill to the coast will cause fluctuations. Once the sun is up and you start to add heat, it gets really complicated. I think that is why you need a degree in weather forcasting to go much further than this.
Hope this helps

[Idan]

That makes a lot of sense, and I understand a good 72% of it. 😆

[MightyAtlas]

Watch the movie Whiteout. It’s very accurate in its depiction of Pole and its weather (including the ‘big’ storm that is rotating counterclockwise instead of clockwise).

[Idan]

@MightyAtlas wrote:

Watch the movie Whiteout. It’s very accurate in its depiction of Pole and its weather (including the ‘big’ storm that is rotating counterclockwise instead of clockwise).

Thanks Atlas, I added it to the netflix queue. Hey, they can’t get everything perfectly right. They’re not The Discovery Channel or National Geographic 😆

[Author]

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