Does the % of oxygen in the atmosphere drop in autumn/winter?

Question

When all the broadfeaf trees in temperate climiates shed their leaves and stop photosynthesising?

Answer 1

when it's winter in the north hemisphere, it's summer in the south...

It's more complicated than that, but yes, the %age of oxygen varies from time to time and from place to place. But not a lot.

Answer 2

In fact, data show that the composition of the atmosphere does have a cyclical variation. There are two major reasons for that.

First, the vast majority of green vegetation lies in the northern hemisphere. I don't remember the exact numbers, but I think the northern hemisphere has about four times the vegetation of the southern hemisphere. Green vegetation inhales CO2 during daylight and exhales O2 at night.

Second, daylight hours are longer in the summer than they are in the winter.

As a consequence, when it is summer in the northern hemisphere, more CO2 is removed and less O2 added to the atmosphere, than when it is winter. Conversely, the atmosphere has less CO2 in winter and more O2.

Because the northern hemisphere has so much more vegetation than the southern hemisphere, it dominates how the O2 and CO2 will be in Earth's atmosphere. These cycles, measured in parts per million, are well documented.

Answer 3

The percnetage of oxygen may vary from place to place depending on the weather and numerous other factors. But the overall percentage of oxygen in the atmosphere of the earth remains constant ...

Answer 4

Mastinox gets the 10 points,
Approximately 21% of Earth's atmosphere is comprised of oxygen it does not change across the horizontal or vertical plane.....But at altitude although O2 is still 21% of the atmosphere there are fewer molecules of it which is what causes hypoxia at altitude.

Answer 5

I should think not for two reasons. One is that while it may be winter here it is summer in the opposite hemisphere and the plants are producing oxygen there (which I assume was the issue that spurred your question) and of course the windy nature of the earth's atmosphere serves to distribute that.

Secondly, cold air is denser than warm air and so the oxygen content in it is compressed, which is one of the reason your car tends to run better on cool days--more oxygen to burn.

Answer 6

No, oxygen is always 21% of atmospheric air. As temperature changes the air will get denser (when cold) or thinner (when warm). Even altitude does not affect this percentage...