<prompt> Qedela umusho olandelayo: Ukuguquguquka kwe-PMM akuguquki. Kokubili isimo sesimo sezulu esijwayelekile - ikakhulukazi amandla okuguquguquka kokushisa kwamanzi olwandle okubangelwa izinguquko zomoya kanye nobubanzi be-ITCZ - kanye nesiphepho ezindaweni ezingaphandle kwe-tropic kuthonya ukuguquguquka kwaso. I-ITCZ ivimbela ubukhulu be-PMM eningizimu, ngakho-ke ukuguquguquka kwesimo se-ITCZ ngenxa yezinguquko zesimo sezulu kungathinta ukubonakaliswa kwe-PMM. Ukulingiswa kukaSanchez et al. 2019 kutholakale ukwanda kokuguquguquka kwe-PMM kokubili ekuphenduleni ukuqhuma kwentaba-mlilo, njengokushaywa kwe-  <response>: Ukuqhuma kwe-Samalas ngo-1257 nokuphendula kumagesi abamba ukushisa. Ukuncipha komsebenzi we-PMM phakathi ne-Holocene kungachaza ukuguquguquka kwe-ENSO ebuthakathaka ngaleso sikhathi; ukwehla okunjalo kungenzeka ukuthi kwabangelwa ukuphoqelelwa komjikelezo. UBramante et al. 2020 uthole ukuhlukahluka okuhle kwe-PMM ngesikhathi se-Medieval Climate Anomaly kanye ne-PMM engemihle ngesikhathi se-Little Ice Age futhi wasisebenzisa ukuchaza izinguquko emsebenzini weziphepho eJaluit eMarshall Islands nasolwandle lwaseNingizimu China. 