Team

Project owner:

Kucera @, Hillebrand @

Team members:

Anne Strack @

Other Researchers:

...

Project Description

Over the last 600 ka, Ear­t­h’s cli­ma­te is do­mi­na­ted by chan­ges in the or­bi­tal geo­me­try (ec­centri­ci­ty) cau­sing gla­ci­al-in­ter­gla­ci­al cy­cles with a fre­quen­cy of ap­pro­xi­mate­ly 100 ka. The­se cy­cles are asym­metri­cal mea­ning long gla­ci­al pe­ri­ods are fol­lo­wed by ra­pid war­mings. Du­ring the­se tran­si­ti­ons – also re­fer­red to as de­gla­cia­ti­ons – the glo­bal cli­ma­te is ra­pidly chan­ging on a mul­ti-mill­en­ni­al-sca­le which ma­kes the­se time pe­ri­ods ide­al to stu­dy po­ten­ti­al ad­ap­ta­ti­on to en­vi­ron­men­tal chan­ge.

Ma­ri­ne plank­ton are of fun­da­men­tal im­port­an­ce when it co­mes to the un­der­stan­ding of the pace and im­pacts that cli­ma­te chan­ge will have on this pla­net. The­re are not only se­veral feed­back me­cha­nisms which high­light the abili­ty of ma­ri­ne plank­ton to cont­ri­bu­te to glo­bal cli­ma­te, but ma­ri­ne plank­ton are also very good in­di­ca­tors for cli­ma­te chan­ge its­elf. They of­ten have short live cy­cles and show a high evo­lu­tio­na­ry di­ver­gence; thus, it ap­pears that plank­ton dy­na­mics may be tight­ly cou­p­led to en­vi­ron­men­tal chan­ge. Also, ma­ri­ne plank­ton – by its de­fi­ni­ti­on – is free floa­ting, so en­vi­ron­men­tal chan­ge might be re­cor­ded by plank­ton dis­tri­bu­ti­on chan­ges and shifts in their geo­gra­phi­cal ran­ge.

A ba­sic goal of the pre­sent PhD pro­ject is to be­ne­fit from the vast amount of plank­ton as­sem­bla­ge data that have been pu­blis­hed in en­vi­ron­men­tal data ar­chi­ves such as PAN­GAEA and NCEI and to uti­li­ze the­se data to bet­ter un­der­stand the va­ria­bi­li­ty in na­tu­ral time sca­les. In par­ti­cu­lar, this PhD pro­ject aims to spa­ti­al­ly and tem­pora­ri­ly in­ves­ti­ga­te the ra­tes of ad­ap­ta­ti­on of ma­ri­ne plank­ton to en­vi­ron­men­tal chan­ge. For that, as­sem­bla­ge as well as mor­pho­lo­gi­cal data extrac­ted from the fos­sil re­cord will be ana­ly­sed.

Duration:

1.2.2019-31.01.2022

Problem statement

Understanding the response of marine ecosystems to climate change requires knowledge of processes that operate over long time scales. Over the last decades, abundant data have been generated on the change in the composition of marine microplankton assemblages across the last deglaciation. These data were used to reconstruct various aspects of the ocean and climate system during this climatic upheaval; however, their potential to evaluate biotic response to climatic forcing has been rarely explored.

Yasuhara et al. (2020) showed a compositional shift in planktonic foraminifera from low to mid latitudes during the last deglaciation by analysing global census data (ForCenS, MARGO). Since they only looked at two time slices (LGM, pre-industrial), they were not able to analyse the timing of this shift in more detail. However, they assume that this shift probably started after the onset of the postglacial warming around 15 ka ago. Here, we use a data set of planktonic foraminifera records (see description below) to analyse the timing and the nature of this transition.

Main Scientific Questions (of first manuscript)

Working Area

North Atlantic Ocean

Data set

We compiled records of plankton response to the last deglaciation covering the entire North Atlantic Ocean. The records comprise assemblage composition data of marine zooplankton (planktonic foraminifera; n = 25) and phytoplankton (coccolithophores and dinoflagellate cysts; n = 5 and 6, respectively) covering the last 24 ka with a resolution of at least 1 ka. The comparability of the data is ensured as follows: For all sites, which are included in the PALMOD 130k marine palaeoclimate data synthesis V1.0 (Jonkers et al., 2020), the provided revised age models are used. For all other sites, which are not included in this synthesis, the same approach was used to revise the published age models to ensure the comparability of all analysed sites.

References

Jonkers, L., Cartapanis, O., Langner, M., McKay, N., Mulitza, S., Strack, A., & Kucera, M. (2020). Integrating palaeoclimate time series with rich metadata for uncertainty modelling: strategy and documentation of the PalMod 130k marine palaeoclimate data synthesis. Earth System Science Data, 12(2), 1053–1081. doi:10.5194/essd-12-1053-2020

Yasuhara, M., Wei, C.-L., Kucera, M., Costello, M. J., Tittensor, D. P., Kiessling, W., … Kubota, Y. (2020). Past and future decline of tropical pelagic biodiversity. Proceedings of the National Academy of Sciences, 117(23), 12891–12896. doi:10.1073/pnas.1916923117