( ( Stratus , ) ( liquid ( , ( low ( cloud ( fraction -LRB- ) ) ) ) ) )
(ROOT (NP (NP (NNP Stratus)) (, ,) (NP (JJ liquid) (, ,) (JJ low) (NN cloud) (NN fraction) (NNS -LRB-))))
Stratus,liquid, low cloud fraction(
(ROOT (S (NP (NNP Stratus) (NNS clouds)) (VP (VBP occur) (PP (IN in) (NP (NP (DT the) (NN low)) (PP (IN of) (NP (DT the) (NNP troposphere)))))) (. .)))