Feature |
|
|
Shape |
Circular, symmetric |
Elongated, asymmetric |
Size |
Smaller, typically tens to hundreds of miles wide |
Larger, typically over a thousand miles wide |
Location |
Tropics and subtropics (5-30 N or S), in local summer |
Mid-latitudes (30-50 N or S), strongest in local winter |
Energy source |
Warm tropical ocean water |
Temperature contrast between air masses |
Atmosphere required for development |
Warm, humid, relatively uniform |
Contrast required between warm/humid and cold/dry air masses |
Location of strongest winds |
Lower atmosphere (below 1 mile) |
Upper atmosphere (around 6 miles) |
Vertical structure |
Aligned in vertical |
Strongly tilted, upper level circulation far from low-level circulation |
Maximum spin rate relative to Earth's spin |
Faster |
Slower |
