Below is a link to a brief animation of barotropic instability in the water-vapor infrared satellite imagery. The thin dark band represents a shear zone associated with a narrow filament of PV. Notice how the filament rolls up into a mesoscale vortex over Montana. Compare this evolution with the numerical simulations on the class home page.
Barotropic vortex-strip instability water-vapor loop.
Below is a link to another animation of barotropic
instability in the water-vapor infrared satellite imagery. Direct your
attention to the far righthand-side of the image. The thin dark band to
the right of the closed low represents a shear zone associated with a
narrow filament of PV. Notice how the filament rolls up into a
mesoscale vortex, with smaller vortices just barely resolved further to
the northwest. Compare this evolution with the numerical simulations on
the class home page.
Barotropic
vortex-strip instability water-vapor loop #2.
Here is example three, perhaps the best example of barotropic instability associated with thinning tropopause filaments.
Barotropic vortex-strip instability water-vapor loop #3.
Here is example four, with 5 minute resolution (from Dan Lindsey, NOAA) of barotropic instability associated with thinning tropopause filaments.
Barotropic vortex-strip instability water-vapor loop #4.
A paper documenting this phenomenon in water vapor imagery by F. Martin Ralph.