Trough and Ridge Amplification
in response to lower level temperature advection
Warm advection beneath an upper level
ridge causes it to build (increase in amplitude),
while cold advection beneath an upper level
trough will contribute to its deepening.
The animation below highlights the amplification of ridge/trough system at
250 mb in response to
intense thermal advection at 850 mb.
The total time elapsed in the
animation is 48 hours.
Observe how the ridge over the
east gradually builds (raises northward)
while the trough over the northern plains gradually
deepens (sinks southward).