( ( ( ( The reason ) ( for ( ( the ( large numbers ) ) ( of ( ( sunspots and ) ( solar outburts ) ) ) ) ) ) ( is ( that ( ( the Sun ) ( is ( at ( ( the peak ) ( of ( its ( 11-year ( sunspot cycle ) ) ) ) ) ) ) ) ) ) ) ( , ( ( called ( the ( Solar Maximum ) ) ) . ) ) )
(ROOT (SINV (S (NP (NP (DT The) (NN reason)) (PP (IN for) (NP (NP (DT the) (JJ large) (NNS numbers)) (PP (IN of) (NP (NP (NNS sunspots)) (CC and) (NP (JJ solar) (NNS outburts))))))) (VP (VBZ is) (SBAR (IN that) (S (NP (DT the) (NNP Sun)) (VP (VBZ is) (PP (IN at) (NP (NP (DT the) (NN peak)) (PP (IN of) (NP (PRP$ its) (JJ 11-year) (NN sunspot) (NN cycle)))))))))) (, ,) (VP (VBD called)) (NP (DT the) (NNP Solar) (NN Maximum)) (. .)))
The reason for the large numbers of sunspots and solar outburts is that the Sun is at the peak of its 11-year sunspot cycle, called the Solar Maximum .
(ROOT (S (NP (NNS Sunspots)) (VP (VBP occur) (PP (IN in) (NP (DT a) (CD 11) (NN year) (NN cycle)))) (. .)))