( ( The stratosphere ) ( ( is ( ( warmer ( ( ( ( ( than ( the ( upper troposphere ) ) ) , ) primarily ) because ) ( of ( a ( stratospheric ( ozone layer ) ) ) ) ) ) ( that ( absorbs ( solar ( ultraviolet energy ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN stratosphere)) (VP (VBZ is) (NP (NP (JJR warmer)) (PP (PP (IN than) (NP (DT the) (JJ upper) (NN troposphere))) (, ,) (RB primarily) (RB because) (PP (IN of) (NP (DT a) (JJ stratospheric) (NN ozone) (NN layer)))) (SBAR (WHNP (WDT that)) (S (VP (VBZ absorbs) (NP (JJ solar) (JJ ultraviolet) (NN energy))))))) (. .)))
The stratosphere is warmer than the upper troposphere, primarily because of a stratospheric ozone layer that absorbs solar ultraviolet energy.
(ROOT (S (NP (DT The) (NN stratosphere)) (VP (VBZ is) (NP (NP (DT the) (NN layer)) (PP (IN above) (NP (DT the) (NNP troposphere))))) (. .)))