252
edits
Changes
m
Fix typo
The boundaries where two air masses meet are known as convergence zones. These can occur in sea breezes or in desert regions. In a sea-breeze front, cold air from the sea meets the warmer air from the land and creates a boundary between two masses of air like a shallow cold front. Glider pilots can gain altitude by flying along the intersection as if it were a ridge of land. Convergence may occur over considerable distances and so may permit virtually straight flight while climbing.
Glider pilots have occasionally been able to use a technique called "dynamic soaring"allowing a glider to gain kinetic energy by repeatedly crossing the boundary between air masses of different horizontal velocity. However, such zones of high "wind gradient" are usually too close to the ground to be used safely by gliders.
Sometimes forms of ridge lift can be got of cliffs like amazing flight shown in [https://www.youtube.com/watch?v=66CaWmbb0ZM this video] on the South coast of England.