Is there less oxygen in the air during winter, since plants shed their leave and cannot photosynthesize?

Answer 1

When deciduous trees shed their leaves, they no longer photosynthesize, but they also no longer respire. You'd need to balance that with animal hibernation, increased combustion for heating, and all other possible effects. Watch a weather program on TV and see how fast air masses move in a day, especially along the jet stream. Any such effect would be miniscule and localized to a place with minimal air circulation. The health of the phytoplankton population would have a much bigger effect. That's why iron fertilization (the "Geritol Solution" to global warming) is so promising.

Answer 2

No. Plant is temperate regions don't contribute nearly enough oxygen to have any measurable effect on the composition of the atmosphere. Any minor effect is simply averaged out. It is like peeing in the ocean. As for the Northern/Southern hemisphere thing, there is more landmass in the northern hemisphere, but it is all splitting hairs. Even if the both hemispheres went to winter at once oxygen level would not be affected because:

1. Photoplankton contributes far more oxygen than terrestrial plants. It does just fine in the winter.

2. Terrestrial plants in the tropics contribute far more oxygen than those in temperate zones.

3. The amount of oxygen in the atmosphere is so large that a few months worth of plant production have very little effect.

A blog article with no references and no author proves me wrong.

Answer 3

That's an interesting question and I've never really thought about it.

A quick search brings up this FAQ.

http://www.earthsky.org/faq/winter-plant-carbon-dioxide-production

"There’s slightly less oxygen during the northern hemisphere winter when most of the world’s trees are bare."

Answer 4

Short answer, yes. Local oxygen levels are minutely smaller when trees are bare. However, the vast majority of oxygen in the atmosphere is released by photosynthetic organisms living in water, which are more or less unaffected by seasonal change.

Answer 5

I don't think so. Air currents are constantly moving around the earth, so I think there is a pretty good mix. The higher up you go, the less oxygen there is, but on the surface I think it is pretty much balanced.

Answer 6

When it is winter in the northern hemisphere it is summer in the southern hemisphere. It all evens out.