Meteorology

You're correct. The actual transfer of heat (thermodynamics) can be left for a whole different discussion, that I really don't care to get into.

From what I read as the original poster's question, it was more directed towards surface pressure.

In meteorology, pressure (in the operational sense) is only measured at the surface. When discussing constant pressure levels (925mb, 850mb, 700mb, 500mb, 300mb, 200mb, and anything in between) the height of the pressure level in question is measured in a different format.

You are correct, heating at the surface is due to conduction, and then any transfer of heat upward is due to convection (think your thermals). Now, just transfer that to the much larger sense of the equator, throw in the large scale global circulations, and then it becomes fairly clear why we have Low pressure along the equator.
 
surreal1221 said:
Moreover, just read what you wrote. You mention temperature and mass and how they relate, then you say something about preventing mass transfer after changing the temperature structure. How would YOU prevent mass transfer after introducing temperature change?
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This is what you call a "thought experiment" in science and has a long tradition. Whether we can actually do them is irrelevant. (Although we can do this one in a laboratory.)

First, the explanation I gave to the OP is correct, and appears in every meteorology book I have; most likely it appears in yours too. The pages I uploaded contain that explanation.

Second, the question arises about whether the upward flow of air is a separate contributor. You seem to regard it as the only causal factor of the low pressure system.

The model that I think you're really going for is when you have convergence at the surface and divergence at altitude (or vice versa).
  • If the rate of divergence at altitude exceeds the rate of convergence at the surface, you will have a net loss of mass from the column of air, which will result in a lowering of surface pressure.
  • If the rate of divergence at altitude is less than the rate of convergence at the surface, you will have a net gain of mass from the column of air, which will result in an increase of surface pressure.
  • If the rate of divergence is equal to the rate of convergence, you will have no change in surface pressure.
My Ahrens book describes this process for the development of storms, but refers to the net convergence/divergence in a number of places. In fact, the process I described is labeled as "convergence".

Do you agree that the model I ascribed to you reflects what you want to convey?
 
Your model is correct.

But your condescending tone in regards to what I wrote is what put me off. Considering your past with me - I really have little patience for discussing much of anything with you. But yes, your model and information above is correct.

What I initially wrote, must not have been as long winded as you would have appreciated, but I've gotten pretty damn good at explaining basic meteorology concepts without making people gouge their eyes out.

The upward column of air, while casual in my language, is obviously connected from the bottom, and the top to our friends convergence, and divergence - along with a number of other factors. We could go on and on about what might/could cause convergence at the SFC and divergence aloft, or vice versa. But I prefer not to considering our audience. Also considering what the original question was. If you wish to get side tracked and discuss and finer details of mass movement through a column of air, when it is pretty cut and dry in semi-permanent pressure centers - knock yourself out. I've gone above and beyond what should have been said, and if you disagree. . .continue. I'll just sit back and critique from this point on.

Focusing back to the OP's original question, it was in regards to surface heating, and constant Low pressure along the equator. That there is what I was addressing MY comments to. Not toward anything you wrote, until you directly quoted me.
 
surreal1221 said:
But your condescending tone in regards to what I wrote is what put me off. Considering your past with me - I really have little patience for discussing much of anything with you. But yes, your model and information above is correct.
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That's because you negated any understanding that I was able to instill, and didn't offer any competing model. That doesn't help anyone. When teaching, it's as important to confirm what is right as it is to correct what is wrong. My challenge to you motivated you to cough up *something*. :)

As for the other, you take things way too personally. Most of us will never meet and so we'll never really know each other. We're all here fundamentally to exchange information and assuming the good will of others facilitates that. It's important not to place too much faith in the "realness" of online relationships, good or bad.
 
Hey Surreal, what's up...interesting conversation you've gotten into.

Anyway, I'm in agreement with Surreal on this one for the most part, others have had correct inputs as well, but for a "quick and dirty" explanation to the answer, Surreal's got it spot on.

I worked with him for a couple years while he was a forecaster...and he was one of the best we had around this place. So there...another weather forecaster approval of his answer.
 
Okay, Im trying to sum all this up...

We have a mass reduction overlying the equator due to raising the pressure levels above and causing air to flow from the equator to the poles in a high to low fashion thus piling mass at the poles and reducing it at the equator (low pressure)

We also then have convergence which creates a lower pressure as the air is lifted. Coriolis and convergence can explain the circulation and presence of the doldrums.

Just another quick question while Im here... Why, as the earth speeds up do we have the development of the three cell theory? Is that just a function of how quickly the earth moves verses the effect of Coriolis and the energy of the airflow it is affecting? Thanks
 
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