EGU2020-19481, updated on 10 Jan 2024
EGU General Assembly 2020
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Deciphering the Signal of Arctic Climate Change

Audrey Morley1,2,3, Markus Raitzsch1,4, Jelle Bijma4,5, Szabina Karancz4,6, and Michal Kucera1
Audrey Morley et al.
  • 1MARUM - Centre for Marine Environmental Sciences, University of Bremen, Bremen, Germany (
  • 2National University of Ireland Galway, Geography, Galway, Ireland
  • 3iCRAG Irish Centre for Research in Applied Geosciences, Ireland
  • 4Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar-und Meeresforschung, Bremerhaven, Germany
  • 5Jacobs University, Bremen, Germany
  • 6Royal Netherlands Institute for Sea Research and Utrecht University, The Netherlands

Whether or not Arctic regions remain(ed) a carbon sink or source to the atmosphere during rapidly warming climates (in the past) is a fundamental question with regards to future global warming and ocean acidification. The boron isotopic composition of planktonic foraminiferal shell calcite (δ11BCc) can potentially provide valuable information of past seawater pH if information on a second carbonate system parameter, temperature, and salinity is available. However, most applications of palaeoceanographic proxies to the cold polar oceans are limited due to a paucity of calibration data, limited information on the calcification habitat, and secondary effects of the carbonate system on the temperature recorded by Mg/Ca values measured in the dominant Arctic species Neogloboquadrina pachyderma sinistral (NPS). Here we present a new Multi-Collector Inductively Coupled Mass Spectrometry (MC-ICPMS) δ11B dataset measured on live NPS collected via plankton tows from the Labrador Sea and Baffin Bay. We compare our results with δ11Bborate derived from pH measurements, δ13C DIC seawater values, temperature and salinity collected at the time and depth the foraminifera calcified. To quantify the control of low carbonate ion concentration on Mg/Ca derived temperatures we measured B/Ca alongside Mg/Ca in the calibration dataset. We are thus able to present a new geochemical correction scheme that can isolate non-thermal controls on the Mg/Ca-temperature relationship for NPS, allowing us for the first time the reconstruction of carbonate system parameters in the Arctic Ocean.

How to cite: Morley, A., Raitzsch, M., Bijma, J., Karancz, S., and Kucera, M.: Deciphering the Signal of Arctic Climate Change , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-19481,, 2020.