Martina Hollstein

My stu­dy is part of a MARUM pro­ject which aims to un­ra­vel the role of oce­ans in cli­ma­te chan­ge. I try to im­pro­ve our un­der­stan­ding about the in­ter­ac­tions bet­ween oce­an and cli­ma­te in the wes­tern tro­pi­cal Pa­ci­fic Oce­an. This re­gi­on is in­te­res­ting because ocean temperatures here are extremely high. Huge amounts of heat and wa­ter va­por are trans­por­ted to the at­mo­s­phe­re. This may im­pact cli­ma­te world­wi­de. In ad­di­ti­on, Pa­ci­fic wa­ters flow into the In­dian Oce­an via the so cal­led In­do­ne­si­an Through­flow (ITF). The ITF is re­gar­ded as a ma­jor com­po­nent of the glo­bal ocea­nic cir­cu­la­ti­on sys­tem and im­portant for the re­gu­la­ti­on of sal­in­i­ty and heat bud­gets of the Pa­ci­fic and In­dian Oce­ans. Against this back­ground, my stu­dy aims to in­ves­ti­ga­te the in­flu­ence of South Pa­ci­fic wa­ter mas­ses on the ITF, and their pos­si­ble in­ter­ac­tion to the wes­tern Pa­ci­fic hy­dro­cli­ma­te du­ring the past. I use geo­che­mi­cal pro­xies like ele­ment ra­ti­os in plank­tic fo­ra­mi­ni­fe­ra shells. Fo­ra­mi­ni­fe­ra are tiny or­ga­nisms li­ving in the wa­ter co­lumn. Their shell com­po­si­ti­on de­pends on pa­ra­me­ters like tem­pe­ra­tu­re or sal­in­i­ty. When fo­ra­mi­ni­fe­ra die, their shells are bu­ried in the seaf­loor se­di­ment, which we can re­co­ver to ana­ly­ze the shell com­po­si­ti­on.

I am con­vin­ced that it is im­portant that more peop­le get a ba­sic un­der­stan­ding about the oce­ans and cli­ma­te chan­ge. Ex­cit­ing sto­ries have the power to reach peop­le and im­part sci­en­ti­fic fin­dings to the so­cie­ty. For me, this project is a great opportunity to learn how we can make science understandable.