PPT Slide
Example of Computing Vertical Motion
1. Assume isentropic surface descends as it is warmed by latent heating (local pressure tendency term):
?P/ ?t = 650 – 550 hPa / 12 h = +2.3 ?bars s-1 (descent)
2. Assume 50 knot wind is blowing normal to the isobars from high to low pressure (advection term):
V ? ? P = (25 m s-1) x (50 hPa/300 km) x cos 180?
V ? ? P = -4.2 ?bars s-1 (ascent)
3. Assume 7 K diabatic heating in 12 h in a layer where ? increases 4 K over 50 hPa (diabatic heating/cooling term):
(d?/dt)(?P/ ??) = (7 K/12 h)(-50 hPa/4K) = -2 ?bars s-1 (ascent)