Milankovitch 100,000 years cycle problem

In summary: However, there are other factors at play (e.g. aphelion being closer to the sun), so it's unclear to what degree the cycles would actually cause an ice age.All else being equal, the planet should get warmer when the orbit is more elliptical, as it intercepts more solar radiation per orbit. However, there are other factors at play (e.g. aphelion being closer to the sun), so it's unclear to what degree the cycles would actually cause an ice age.
  • #1
Bjarne
344
0
According to the Milankovitch 100,000 years cycles, there is a problem.
The orbit of the Earth will change to a gradually more ecliptic orbit, and it will be a bit colder when this happen.
But the problem is that this is not enough to explain ice ages.
How much is missing.
I mean how much further away from the Sun should we get when the 100,00 years cycles should be the cause of ice ages. Is it for e.g; 10,000,000 million km further away from the sun?
http://en.wikipedia.org/wiki/Milankovitch_cycles
 
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  • #2
I mean is it for example Is it for e.g; 10,000,000 km (not million km)
 
  • #3
Do you mean that the orbit will be come more Eliptical? If so, if we become more elicptical, then we will be further from the sun during Apogee, but closer during Perigee than we are now, which should cancel out each other I thought.
 
  • #4
Drakkith said:
Do you mean that the orbit will be come more Eliptical? If so, if we become more elicptical, then we will be further from the sun during Apogee, but closer during Perigee than we are now, which should cancel out each other I thought.

Yes this is what I mean
I am not sure this will cancel out each other, not according to Milankovitc so far I understand
 
  • #5
Bjarne said:
Yes this is what I mean
I am not sure this will cancel out each other, not according to Milankovitc so far I understand

Hrmm. I don't think I can help you on this one, sorry.
 
  • #6
Things don't cancel cleanly.

On one hand, you might think that more a more elliptical orbit means a colder Earth. Objects move slower at aphelion, so Earth will spend more time farther than average than closer than average.

On the other hand, you might think that a more elliptical orbit means a warmer Earth. Perihelion is subject to the inverse square law, so a little closer means a lot warmer.

Inverse square wins. More elliptical means more insolation/year (warmer).
 
  • #7
Tony, you are saying that because of the inverse square law the amount of radiation absorbed by the Earth when it is near the sun will more than cancel out the lesser amount when the Earth is further away?
 
  • #8
The amount of radiation absorbed is proportional to the inverse square of the distance. Let's look at an orbit with a semi-major axis of 1 AU. If circular, let's call the amount of insolation 1. Now let's consider an orbit with an eccentricity of 0.1. This means that perihelion is at 0.9 AU and aphelion is at 1.1 AU. The average amount of insolation received while at these extremes is
((1/0.9^2) + (1/1.1^2)) / 2 = 1.03
Partially offsetting this is the fact that a planet will spend more time at aphelion.

Here's a table showing how much additional insolation a planet receives due to eccentricity. Insolation = 1 for a circular orbit.
Code: 
0.0    1.000
0.1    1.005
0.2    1.021
0.3    1.049
0.4    1.091
0.5    1.155
0.6    1.251
0.7    1.401
0.8    1.668
0.9    2.300
 
  • #9
Ah ok i see. Thanks Tony.
 
  • #10
tony873004 said:
The amount of radiation absorbed is proportional to the inverse square of the distance. Let's look at an orbit with a semi-major axis of 1 AU. If circular, let's call the amount of insolation 1. Now let's consider an orbit with an eccentricity of 0.1. This means that perihelion is at 0.9 AU and aphelion is at 1.1 AU. The average amount of insolation received while at these extremes is
((1/0.9^2) + (1/1.1^2)) / 2 = 1.03
Partially offsetting this is the fact that a planet will spend more time at aphelion.

Here's a table showing how much additional insolation a planet receives due to eccentricity. Insolation = 1 for a circular orbit.
Code: 
0.0    1.000
0.1    1.005
0.2    1.021
0.3    1.049
0.4    1.091
0.5    1.155
0.6    1.251
0.7    1.401
0.8    1.668
0.9    2.300

How can the Milankovitch 100,000 years cycles then be taken serious?
It should according to that (which I understand many supports) be colder when the orbit is more elliptical..
 
  • #11
Bjarne said:
How can the Milankovitch 100,000 years cycles then be taken serious?
It should according to that (which I understand many supports) be colder when the orbit is more elliptical..

All else being equal, the planet should get warmer when the orbit is more elliptical, as it intercepts more solar radiation per orbit.
 

FAQ: Milankovitch 100,000 years cycle problem

1. What is the Milankovitch 100,000 years cycle problem?

The Milankovitch 100,000 years cycle problem refers to a long-term variation in Earth's climate, which occurs approximately every 100,000 years. It is caused by changes in Earth's orbit and axial tilt, known as Milankovitch cycles, which can affect the amount of solar radiation received by the Earth's surface.

2. How long has the Milankovitch 100,000 years cycle problem been occurring?

The Milankovitch 100,000 years cycle problem has been occurring for millions of years. It is a natural phenomenon that has been observed in geological records and has played a significant role in shaping Earth's climate over long periods of time.

3. What evidence supports the existence of the Milankovitch 100,000 years cycle problem?

There is strong evidence from various sources, including geological records, ice cores, and satellite measurements, that supports the existence of the Milankovitch 100,000 years cycle problem. These records show recurring patterns in Earth's climate that align with the Milankovitch cycles.

4. How does the Milankovitch 100,000 years cycle problem affect Earth's climate?

The Milankovitch 100,000 years cycle problem can have a significant impact on Earth's climate by influencing the amount of solar radiation received by the Earth's surface. When the Earth is closer to the sun and tilted towards it, it receives more solar radiation, leading to warmer temperatures. Conversely, when the Earth is further away and tilted away from the sun, it receives less solar radiation and experiences cooler temperatures.

5. Is the Milankovitch 100,000 years cycle problem responsible for current climate change?

No, the Milankovitch 100,000 years cycle problem is a long-term natural cycle that occurs over thousands of years. It is not responsible for the rapid climate change that is currently being observed, which is largely caused by human activities such as burning fossil fuels and deforestation.

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