Atmospheric Processes. Air Movements Surface Winds Pressure Systems Characteristics of high & low pressure systems Influence of high & low pressure systems on weather patterns Air Masses. What if…. The earth was not tilted 23.5° on its axis? It did not rotate once every 24 hours?
Hadley cell - Low latitude air movement toward the equator that with heating, rises vertically, with poleward movement in the upper atmosphere. This forms a convection cell that dominates tropical and sub-tropical climates.
Between each of these circulation cells are bands of high and low pressure at the surface. The high pressure band is located about 30° N/S latitude and at each pole. Low pressure bands are found at the equator and 50°-60° N/S.
Air moves from HIGH to LOW pressure – variable speed and direction but have an overall global pattern
Remember – Coriolis Effect – these winds are deflected
Atmospheric pressure systems are areas of the atmosphere with relatively high or low barometric (air) pressure
Surface atmospheric pressure is shown on synoptic charts as isobars
Isobars join areas of equal pressure – like contour lines join areas of equal height