# Tag Info

8

There is no evidence that Earth had a much greater axial tilt so long ago. To my knowledge, the evidence for changes in the axial tilt of the Earth is based on ocean sediment cores (see http://en.wikipedia.org/wiki/James_Hays ) and ice cores ( see http://en.wikipedia.org/wiki/Milankovitch_cycles#Axial_tilt_.28obliquity.29 ). However, these only go back ...

7

It thus seems reasonable to say we are entering another Ice Age according to Milankovitch cycles. Some of the Milankovitch conditions would appear to make the Earth ripe for a new glacial epoch starting now, or perhaps a few hundred years ago. In particular, aphelion occurs in early July, and obliquity is low. Both of these make for mild northern hemisphere ...

5

A simple way to estimate the implications is to simplify the problem. If the orbits of Earth, Sun and Moon were circular and in the same plane, and the Earth had no tilt, the only remaining tidal constituents would be $M_2$ and $S_2$ (also the overtides and combination tides: $M_4$, $MS_4$...). The rest of the tidal constituents can be expressed as linear ...

5

What changes in climate pattern can be observed when obliquity is at the extremes? While obliquity is easily googled, the specific effects globally aren't as easy to look up, so I'll give this one a shot. For starters, the 41,000 year variation isn't precise. It fluctuates some, having to do with the earth and other planets not being perfect spheres and ...

4

Orbital cycles doubtlessly play a role in the Quaternary climate record, together with other effects like ice sheet dynamics, but their effect is dwarfed by speed and amount of the current climate change. Even if we were in for a new glaciation from orbital parameters alone (which is not the case), there'd be no use counting on it because they work on longer ...

4

If we consider that by "Assume daily cycle and convection and so on operate as usual" you meant that all heat transport from/to the pole remain as it is today. Then, we can do a back of the envelope calculation. This calculation will at least give you an order-of-magnitude answer, and we can then consider everything that would affect the result. Currently ...

3

Any object with a non-spherical moment of inertia tensor that is subject to a non-uniform gravitational field will experience a torque due to the gradient of the gravitational field. This can result in a benefit or a challenge for artificial satellites. The Earth has a non-spherical moment of inertia tensor due to its equatorial bulge, and the Moon's and ...

2

In a short timescale, let's say one or two years after a permanent equinox state, the temperature would be basically the current mean annual temperature. This is because if we take the premise of keeping heat transport by convection (on the sea and the atmosphere) as it it today, the total energy inputs and outputs would be the same. Therefore, the same mean ...

2

Just throwing some thought on the subject, it is easy to me to understand that there is a big pump moving large amount of water from one pole to the opposite one along the year, that is during summer in north hemisphere the ice melts at Arctic and mix to the sea; at the same time water start precipitating more and more on the Antarctica, piling up as snow ...

2

I cannot answer your hypothetical question, but the tilt does probably affect the tides and there have been some studies on the topic. Hopefully they can inspire to further ideas and speculations. It appears that the main outcome from the report should be for you to understand how the moon, the Sun and the Earth control the tide and how the tidal force works....

1

"Obliquity of the ecliptic for 20,000 years, calculated by Laskar (1986) reflects change from 24.2° to 22.5°. Diagram Until 1983 the obliquity for any date was calculated from work of Newcomb, who analyzed positions of the planets until about 1895: ε = 23° 27′ 08″.26 − 46″.845 T − 0″.0059 T2 + 0″.00181 T3 where ε is the obliquity and T is tropical ...

1

Check out this matlab program that is presented in a paper by Kostadinov and Gilb, 2014. The paper is worth reading, and they have their full matlab code in the "supplement" link (top right corner under downloads). The code launches a GUI. From it you can control the values of obliquity, eccentricity, precession, total solar irradiance, day of year, ...

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