( ( Changes ( in ( altitude ( or ( air pressure ) ) ) ) ) . )
(ROOT (NP (NP (NNS Changes)) (PP (IN in) (NP (NN altitude) (CC or) (NN air) (NN pressure))) (. .)))
Changes in altitude or air pressure.
(ROOT (S (NP (NNP Air) (NN temperature)) (VP (VBZ changes) (PP (IN as) (NP (NN altitude) (NNS increases)))) (. .)))