Air is constantly circulating as it is heated at the bottom of the troposphere, expands and rises to the tropopause (the &quot;lid&quot;).
(Air; is constantly circulating; T:as it is heated at the bottom of the troposphere) (it; is heated; L:at the bottom of the troposphere) (Air; expands; )
Air it Air
is constantly circulating is heated expands
T:as it is heated at the bottom of the troposphere
L:at the bottom of the troposphere