| View previous topic :: View next topic |
Chad
In: Ramsbottom
|
|
 |
|
| Ishmael wrote: | | Is there a way we can expand the atmosphere on the sunlit side of the planet without first having to heat it up? |
We don't need to actually increase the temperature... but we need to either increase the kinetic energy of the air molecules, or decrease the atmospheric pressure.
|
|
 |
|
 |
|
Grant
|
|
|
|
But because the coldest part of the night is just before sunrise (having spent all night without the sun's influence) and the hottest part of the day isn't just before sunset (for obvious reasons) there is a thermal imbalance between east and west and the expansion and contraction are not equal and opposite.
This then sets up a net rotation of the atmosphere from west to east, in the way I described earlier... a bit like a fluid motor of sorts. |
But, Chad, each part of the earth's surface will go through the dry part and the wet part each day. And on average the two must balance each other out. So how does the water move faster than the Earth moves?
|
|
| |
|
|
|
Grant
|
|
|
|
Perhaps the water just follows the Sun? Here's a thought experiment to show how this could happen.
Imagine a point in the atmosphere which is closest to the Sun. Call it point A. Then imagine the point on the other side of the globe and furthest away, point B. The atmosphere is a water pump, taking water from A and depositing it at point B.
Imagine further that you are a point on the Earth's surface called Nigel (it's as good a name as any). When Nigel reaches point A moisture evaporates, leaving him a bit dry. But he's not worried because he knows he will get it back later when he reaches point B.
Imagine his surprise when he gets to B and there's no water. Instead his neighbour, Colin, who lives in the east, is getting his water. Why? Because the Earth is moving around the Sun and the division between the light side and dark side is moving faster than the Earth is turning!
|
|
| |
|
|
|
Chad
In: Ramsbottom
|
|
|
|
| Grant wrote: | | But, Chad, each part of the earth's surface will go through the dry part and the wet part each day. And on average the two must balance each other out. So how does the water move faster than the Earth moves? |
Because the differential expansion and contraction between east and west (due to the uneven temperature gradient) sets the atmosphere in motion, which then continues to rotate, relative to the Earth's surface, under its own momentum, carrying the moisture with it.
The continuous expansion and contraction provides the impetus to keep it going... like hip movements keeping a hula hoop in motion.
|
|
| |
|
|
|
Chad
In: Ramsbottom
|
|
|
|
| Grant wrote: | | Why? Because the Earth is moving around the Sun and the division between the light side and dark side is moving faster than the Earth is turning! |
Too slow.
It would take an entire year to get back to the starting point... We need to get our net moisture transfer going somewhat faster than that.
(I'm sticking with my Hula Hoop Effect.)
|
|
| |
|
|
|
Ishmael
In: Toronto
|
|
|
|
| Chad wrote: | | We don't need to actually increase the temperature... but we need to either increase the kinetic energy of the air molecules, or decrease the atmospheric pressure. |
You see. I think the air warms because the atmosphere expands.
|
|
| |
|
|
|
Ishmael
In: Toronto
|
|
|
|
| Chad wrote: | | (I'm sticking with my Hula Hoop Effect.) |
All that does is explain why the wind blows, which may or may not be correct but is certainly a step too far.
The wind as we have it is sufficient to move moisture in the air from the west to east. The only difficulty arises where prevailing winds are said to be to be east-to-west.
In the past, we have assumed that closer scrutiny would eventually reveal that, even here, most of the air volume moves west-to-east.
Should this fail to be the case, it is my argument that the narrowness of the east-to-west corridor is sufficient to insure a still generalized eastward trend for moisture and sand carried in the equatorial atmosphere.
|
|
| |
|
|
|
Brian Ambrose
|
|
|
|
| You see. I think the air warms because the atmosphere expands. |
This makes no sense to me. First, a gas 'warms' when you compress it (all those molecules bouncing around with nowhere to go, or if you prefer, there's the same amount of total energy in a smaller space), and cools when it expands. Doesn't it? Second, I seem to observe that the lower the air pressure, the cooler it is. The higher you go, the lower the air pressure and the lower the air temperature. That's why mountains are cold.
|
|
| |
|
|
|
Grant
|
|
|
|
Too slow.
It would take an entire year to get back to the starting point... We need to get our net moisture transfer going somewhat faster than that. |
By my reckoning the moisture pump is moving at 68 miles per day around the equator (25,000/365). How fast do you want it to go?
|
|
| |
|
|
|
Ishmael
In: Toronto
|
|
|
|
| Brian Ambrose wrote: | | This makes no sense to me. First, a gas 'warms' when you compress it (all those molecules bouncing around with nowhere to go, or if you prefer, there's the same amount of total energy in a smaller space), and cools when it expands. Doesn't it? |
Think Volume. Keep the overall density the same but add more air and thus expand the volume of the atmosphere = air at ground level gets warmer. That's my hypothesis. My suspicion is that atmospheric volume is greater on the day-side of the planet than it is on the night side.
| Second, I seem to observe that the lower the air pressure, the cooler it is. The higher you go, the lower the air pressure and the lower the air temperature. That's why mountains are cold. |
Yes. But is it air density or volume? And is the latter a factor of the former?
Increase the total atmospheric volume and air pressure at the bottom goes up. Which equals a rise in temperature.
Night time air density at sea level -- is it lower than daytime air density?
|
|
| |
|
|
|
Ishtar
|
|
|
|
| Ishmael wrote: |
Night time air density at sea level -- is it lower than daytime air density? |
Density is so varied based on temperature, pressure, and humidity. If the temperature and humidity are lower probably the air itself is more dense.
|
|
| |
|
|
|
Chad
In: Ramsbottom
|
|
|
|
| Ishmael wrote: | | [My suspicion is that atmospheric volume is greater on the day-side of the planet than it is on the night side. |
Solar tidal effect.
|
|
| |
|
|
|
Ishmael
In: Toronto
|
|
|
|
| Chad wrote: | | Ishmael wrote: | | [My suspicion is that atmospheric volume is greater on the day-side of the planet than it is on the night side. |
Solar tidal effect. |
Way ahead of you.
Solar tidal effect is the primary culprit in what I am getting at -- that and equatorial bulging from rotational forces. Together, they explain both the seasons and the gradation of temperature from equator to pole.
The problem is that tidal effects create opposed bulges -- the atmosphere bulges out due to the solar tide on both the night and day sides of the planet. I need a special effect that makes the solar side bulge more -- in order to explain the temperature difference between day and night.
Is there an aspect of tidal theory I am missing?
(btw - our group spent two years hashing out tidal theory -- the orthodoxy on the subject is surprisingly muddled)
|
|
| |
|
|
|
Ishmael
In: Toronto
|
|
|
|
| Ishtar wrote: | | If the temperature and humidity are lower probably the air itself is more dense. |
I am reversing the presumed cause and effect relationship.
|
|
| |
|
|
|
Chad
In: Ramsbottom
|
|
|
|
| Ishmael wrote: | The problem is that tidal effects create opposed bulges -- the atmosphere bulges out due to the solar tide on both the night and day sides of the planet. I need a special effect that makes the solar side bulge more -- in order to explain the temperature difference between day and night.
Is there an aspect of tidal theory I am missing? |
If I understand things correctly, the two bulges are not equal and opposite.
The sun- side bulge is produced by Sol's gravity, whereas the bulge on the far side is a result of a slight eccentricity in orbit (as Earth and Sol rotate around their joint centre of gravity).
Lunar tidal bulges may (by coincidence) be of roughly equal proportions, but I doubt this is the case with Solar tidal bulges... I would expect the gravitational bulge to be much larger than that caused by the eccentric orbit.
|
|
| |
|
|
|
|
The Library Index 
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in 
