<div class="eI2">Geopotential height Temperature at 500 hPa </div>
Geopotential height at 500 hPa (solid line)<br>
Temperature at 500 hPa (colored, dashed)<br><br>
The maps show the predominant tropospheric waves (trough or ridge).
They virtually control the ''weather'' (dry, warm / wet, cold) and the long waves 
drive the smaller synoptic waves.
Thus, this upper-level chart illustrates the dynamics of our atmosphere.
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