First observed by World War II pilots, they develop just below the tropopause over areas of steep pressure gradient on the surface.
42.
In the upper troposphere the tropopause slants downward the further north in latitude and there is more high potential vorticity stratospheric air northward.
43.
In general, winds are strongest immediately under the tropopause ( except locally, during tornadoes, tropical cyclones or other anomalous situations ).
44.
Although the temperature may be at the tropopause, the top of the stratosphere is much warmer, and may be near 0 �C.
45.
The decreased water content is a result of a lower tropopause within the vortex, which places dry stratospheric air above moist tropospheric air.
46.
By dropping the extra ballast just before entering the tropopause, the crew hopes to speed up the balloon's ascent to safer altitudes.
47.
On Earth, the main jet streams are located near the altitude of the tropopause and are westerly winds ( flowing west to east ).
48.
Because the temperature in the tropopause and lower stratosphere is largely constant with increasing altitude, very little convection and its resultant turbulence occurs there.
49.
After reaching the tropopause, the bottom of the region of strong static stability, the cloud tends to slow its ascent and spread out.
50.
The Great Dark Spot generated large white clouds at or just below the tropopause layer similar to high-altitude cirrus clouds found on Earth.
