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We can understand the general circulation of the atmosphere by formulating a general theory of the Hadley Cell and its development and progression. Due to the uneven heating of the earth, the equator receives significantly more solar radiation and thermal energy than do higher latitudes. As a result, rising motion and convection occur in this the region known as the intertropical convergence zone (ITCZ). As a result of this rising motion, at the surface air moves equator-ward to  replace the air displaced by convection, and air moves poleward aloft before sinking again at about 30^o latitude. Thus the formation of the atmospheric "Hadley Cell". Conservation of angular momentum with this northward and southward motion dictates the formation of westerly and easterly winds, and above 30^o latitude, a different regime sets in, in which northward flow combined with the coriolis effect and the thermal gradient with the cold polar regions leads to a more inconsistent regime in which eddies play a major role. The main features of the Global Circulation can be seen below in Figure 2.1.

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Figure 2.1: The Global Circulation, highlighting both the Hadley Cell and the mid latitude patterns, as well as surface winds. 

In the mid latitudes where the Coriolis force is large (unlike in the equatorial regions), the high rotation rate turns what would otherwise be smooth laminar flow, into turbulent flow and the pattern of mid latitude cyclones, also known as 'transient's or 'eddies', that play an important role in transporting heat from the equator to the pole.

As a result of the Hadley Cell alone, we can observe the formation and location of the subtropical jet stream and equatorial easterly winds, consistent with angular momentum conservation, as seen in Figure 2.2.

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Figure 2.2: The Hadley Cell in cross-section, highlighting both the Wind Patterns that result from it's formation.

In the mid latitudes, poleward motion leads to cyclonic motion under the Coriolis effect. At the boundary between the warmer mid latitude air and the cold polar air, we also observe the jet stream, the increase of wind with height as predicted by the thermal wind Equation 1.

$x^3 + 5$$\frac{\partial u}{\partial p} = \frac{R}{fp}\hat{z}\times \Delta T$

Laminar Flow in Tank: Analysis and Results

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