What If Earth Had a 45 Degree Tilt?

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In summary: High-latitude summer temperatures go up as one might expect, and the poles would be much colder than they are now because they would be in the arctic circle for much of the year. There would be more seasonal variation in the tropics (the equator would be at its coldest in the summer and the winter, though this is true now too).
  • #1
willstaruss22
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What would Earth be like with a 45 degree tilt?
 
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  • #2
If Earth had a 45 degree tilt, everything north of 45 degrees (even Seattle, Washington) would technically be in the arctic circle, and everything south of 45 degrees would be in the antarctic circle (which surprisingly adds little more than the southern tips of south America and New Zealand). You could see the midnight sun in Paris on a summer day.

The weather at the poles would also be more extreme. The polar winters would be even harsher than they are now because for months at a time even more land and see would never see sunlight.
 
  • #3
south of 45 degrees south, that is...
 
  • #4
jfizzix said:
If Earth had a 45 degree tilt, everything north of 45 degrees (even Seattle, Washington) would technically be in the arctic circle, and everything south of 45 degrees would be in the antarctic circle (which surprisingly adds little more than the southern tips of south America and New Zealand). You could see the midnight sun in Paris on a summer day.

The weather at the poles would also be more extreme. The polar winters would be even harsher than they are now because for months at a time even more land and see would never see sunlight.

But you'll get a lot more sun at the poles on average and less in the tropics.
At the north pole you'll still get a half year of sun in the summer, but now it goes through an altitude of 45 degrees and not 23, so you'll get sin(45)/sin(23) = about 79% more sun on average.
 
  • #5
That's also true. Arctic summers could be extremely warm because of all the extra sun, and there would be more seasonal variation in the tropics (the equator would be at its coldest in the summer and the winter, though this is true now too)
 
  • #6
willem2 said:
But you'll get a lot more sun at the poles on average and less in the tropics.

um, no, i don't think that is the case.

assuming that the Earth would continue to spin and continue to revolve around the sun, every spot on Earth would see the sun 50% of the time on average as each spot does now. this is not to say that some spots on Earth don't get a more direct hit from the sun at noon.
 
  • #7
rbj said:
um, no, i don't think that is the case.

assuming that the Earth would continue to spin and continue to revolve around the sun, every spot on Earth would see the sun 50% of the time on average as each spot does now. this is not to say that some spots on Earth don't get a more direct hit from the sun at noon.

The angle of incidence is very important in terms of ground heating. The poles would experience a 45 degree angle of incidence at the summer solstice compared to the 23 degree maximum angle that actually occurs. Meanwhile the sub-solar point would dip to 45 N&S at the solstices meaning the angle of incidence at the equator at noon is 45 degrees at each solstice compared to the about 90-23= 67 degrees that actually occurs.
 
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  • #8
willstaruss22 said:
What would Earth be like with a 45 degree tilt?

It's precession of the equinoxes would likely also be more extreme. Precession is one factor that has been attributed to the cause of ice ages. See Milankovich Cycles:

http://www.climatedata.info/Forcing/Forcing/milankovitchcycles.html [Broken]
 
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  • #9
jackmell said:
It's precession of the equinoxes would likely also be more extreme. Precession is one factor that has been attributed to the cause of ice ages. See Milankovich Cycles:

http://www.climatedata.info/Forcing/Forcing/milankovitchcycles.html [Broken]

While this is true, I think a 45 degree tilt would work against an ice age. The key to continental glaciation is a perennial snow pack. With the amount of insolation over the polar regions due to the sun circling at high angles (peaking at 45 degrees at the solstice), it's unlikely that significant winter snow could survive though the summer even with the other conditions preceding the last ice age. Your reference pointed out the importance of temperatures in July at 65 degrees N. Note the 45th parallel would correspond not only to the Arctic circle, but also the Tropic of Cancer in the northern hemisphere. The sub-solar point would be only 20 degrees south of the of the 65th parallel at the solstice.

I can't say an ice age would not occur, but the conditions at the outset of the Pleistocene glaciations were just sufficient to get the glaciers started with a 23 degree tilt according to the article you posted.
 
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  • #10
Extraordinary climates of Earth-like planets: three-dimensional climate simulations at extreme obliquity goes into a lot of detail, but mainly for the extreme case of 85d tilt. It also discusses simulations for 54d and 70d.

So one has to interpolate for the 45d case.

High-latitude summer temperatures go up as one might expect, and there is likely less persistent ice. Low-latitude temperatures go down, since the Sun is close to the zenith for less of the year.

I've found
[0807.4180] Habitable Climates: The Influence of Obliquity
Climate of an Earth-like Aquaplanet at High Obliquity
http://www3.geosc.psu.edu/~jfk4/Abiol_574/Readings/Laskar&Robutel_Nature_93.pdf [Broken]

but they are more difficult to interpret.
 
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  • #11
Seasonal differences would be much greater. There would be repercussions for very long cycles of light intensity.
 

1. How would a higher tilt of Earth affect the seasons?

If Earth had a higher tilt, the seasons would become more extreme. This means that summers would be hotter and winters would be colder. The difference between the amount of sunlight received during summer and winter would also be greater.

2. Would a higher tilt of Earth affect the length of days?

Yes, a higher tilt of Earth would affect the length of days. This is because the tilt of Earth determines the angle at which sunlight hits the surface, thus affecting the amount of daylight received in a day. With a higher tilt, the length of days would vary more throughout the year.

3. How would a higher tilt of Earth impact the climate?

A higher tilt of Earth would impact the climate by causing more extreme weather patterns. This is due to the fact that the tilt affects how much sunlight different areas of Earth receive, leading to variations in temperature and precipitation. It could also alter ocean currents and wind patterns, further affecting the climate.

4. Would a higher tilt of Earth affect the Earth's orbit?

Yes, a higher tilt of Earth would affect the Earth's orbit. This is because the tilt of Earth affects the distribution of solar energy on the planet, which in turn affects gravitational forces. This could potentially lead to changes in the Earth's orbit and its position in relation to the Sun.

5. How would a higher tilt of Earth impact life on the planet?

A higher tilt of Earth could have significant impacts on life on the planet. It could lead to changes in ecosystems, as different species may struggle to adapt to the more extreme seasons and climate. It could also affect agriculture and food production, as seasonal changes would become more pronounced. Overall, a higher tilt of Earth could greatly impact the survival and evolution of many species.

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