( ( ( Pressure changes ) ( at ( ( ( ( a ( given location ) ) ( at ( ( the ( Earth 's ) ) surface ) ) ) ( as ( ( a result ) ( of i ) ) ) ) -RRB- ) ) ) ( ( ( air ( ( ( ( mass advection ) , ) ii ) -RRB- ) ) ( local effects ) ) . ) )
(ROOT (S (NP (NP (NN Pressure) (NNS changes)) (PP (IN at) (NP (NP (DT a) (JJ given) (NN location)) (PP (IN at) (NP (NP (DT the) (NN Earth) (POS 's)) (NN surface))) (PP (IN as) (NP (NP (DT a) (NN result)) (PP (IN of) (NP (FW i))))) (-RRB- -RRB-)))) (VP (NN air) (PRN (NP (NP (JJ mass) (NN advection)) (, ,) (NP (NN ii))) (-RRB- -RRB-)) (NP (ADJP (JJ local)) (NNS effects))) (. .)))
Pressure changes at a given location at the Earth's surface as a result of i) air mass advection, ii) local effects.
(ROOT (S (NP (NP (DT The) (NN movement)) (PP (IN of) (NP (NP (DT an) (NN air) (NN mass)) (PP (IN over) (NP (NP (NN earth) (POS 's)) (NN surface)))))) (VP (VBZ causes) (NP (JJ local) (NN weather) (NNS changes))) (. .)))