UPPER-LEVEL WINDS. Atmospheric pressure, temperature and winds at surface. Weather conditions. Atmospheric pressure and elevation. Winds at upper level (500mb = ~5600 m of elevation or 18000 feet). 1 knot = 1 “nautical” mile/h 1 knot = 1.15 MPH 1 knot = 1.85 km/h.
Atmospheric pressure, temperature and winds at surface
1 knot = 1 “nautical” mile/h
1 knot = 1.15 MPH
1 knot = 1.85 km/h
How does air move at higher elevations?
The gradient force INCREASES with altitude stronger winds
How does pressure changes with elevation?
Pressure decreases with elevation:
SLOWER in WARMER air
FASTER in COLD air
Height (of pressure):
HIGH in WARMER air
LOW in COLDER air
Figure 5.17, Page 139
When the Coriolis force balances the gradient force.
The speed and direction of wind remain constant
It takes place at upper levels
(See Fig 5.19)
2. Warm air pushes pole ward and a tongue of cold air is moved to south (undulation development)
3. Waves are strongly developed. Cold air are “troughs” of low pressure
4. Waves are pinched off, forming cyclones of cold air
The greater the contrast in temperature, the stronger the jet streams blow