Convergence.

Not my understanding of the subject at all. …

Originally posted by Encyclopedia Britannica:

from climate:

Relationships to surface features
Upper-air circulations play a key role in the development and propagation of surface pressure systems. The surface pressure is simply the weight per unit area of the air above the surface.

Thus, in order to change the surface pressure, it is necessary to change the mass content of the overriding air. Because large amounts of mass are transferred by upper-air flows, such flows are capable of forcing significant changes in surface pressure.

The transfer of mass by upper-air circulations occurs in a very nonuniform fashion. As a result, mass tends to build up (mass convergence) in some regions and be depleted (mass divergence) in others.

If these convergences or divergences occurred uniformly at all levels above a given surface location, it would be easy to anticipate the resulting surface-pressure changes. Such uniformity, however, is not observed. Rather, divergences in one portion of a column of air are largely compensated by convergences in another. Thus, changes in surface pressure may result from the subtle differences between these conflicting mass divergence/convergence patterns.

(Picture to be added later)
Figure 7: Vertical cross sections through a wave system depicting typical divergence/convergence…. Also included are the directions of the vertical air motions required to satisfy mass conservation principles.

Such vertical motions are typically very small compared to horizontal motions yet are important because they are largely responsible for the formation or dissipation of clouds. Clouds form in regions of upward motion if sufficient moisture is present and dissipate in those of downward motion.

In tilting wave systems, this accounts for the occurrence of inclement weather with low pressure and fair weather with high pressure.

In a non-tilting system, which is characteristic of an occluded cyclone (see above), the bulk of the upper-air divergence and convergence occurs between surface low (L) and high (H) centres, with little happening immediately above the centres.

This signifies a propagating wave–a very slow one in some cases–with little intensification of the surface centre. In fact, decay (filling) of the surface centre might occur because of frictionally induced mass convergence in the low and divergence from the high, which is not compensated for by corresponding upper-air mass divergence and convergence.

In the tilting system, much of the upper-air divergence and convergence lies above the surface centres. In this case, opportunities are much better for decreasing or increasing the mass above the cyclone or anticyclone, respectively, and thus for intensifying the surface centre. Such a wave also will propagate in the general direction of the mean tropospheric flow.

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2 thoughts on “Convergence.

  1. It is highly likely that the heat source for weather and etc. is not confined to the light from the sun but on the disposal of friction in the mechanics of orbits: Celestial Mechanics.Celestial Mechanics is the term given to the operation of planets and stars. For a century now, the Theory of Relativity, or more accurately all of the theorise of relativity, claim the aberrant behaviour of planets such as Mercury are the result of gravitational pressure.Don't ask me how or why the forces involved don't just transform into other phenomena such as the way heat and motion do and electricity and magnetism does.It strikes me that Mercury's behaviour is more likely something to do with the physics of dynamics. It's almost invisible to us but the liquids on board it must operate the way they do on Venus and Earth.Who can say?

  2. I have always thought there was a step between the three body problem and any direct occurrences because of the sun and moon. Such is a given for ocean tides and the same is true for so called disastrous phenomenon.It is only logical that there is more to this next order of magnitude; the oscillating of its air pressure systems and the oscillation of the whole set of seas. (As an aside I wonder how the Arctic ice fits in.Maybe that too is down to a negative oscillation in the Arctic.) The background noise: The atmosphere makes a lot of noise as do the oceans. Where does this noise go?If it perpetuates the acoustics that end up as earthquakes then what is the original cause of the noise?Fluids rushing past one another.But then what causes them to move? It isn't direct action from the moon, sun or planets is it. For a long time we have known it has to be the heat of the sun causing the weather. And then again this weather takes place at night too.It's all very confusing. Like trying to analyse what may turn out to be a perpetual motion machine.http://groups.google.com/group/uk.sci.weather/browse_frm/thread/0488eafcc6f20732/8b94ea7e7fa4e693#8b94ea7e7fa4e693

    Warning:
    Some trolling of a stalker.
    I usually just ignore such odd bods these days but at one time I used to get really upset with them.

    I now realise that some people just can't see what they are doing. Such megalomania is better on-line than it is in world politics. Pity it is not confined here.

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