DOI: 10.1016/j.epsl.2018.02.002
Scopus记录号: 2-s2.0-85044766528
论文题名: Boron isotope-based seasonal paleo-pH reconstruction for the Southeast Atlantic – A multispecies approach using habitat preference of planktonic foraminifera
作者: Raitzsch M. ; Bijma J. ; Benthien A. ; Richter K.-U. ; Steinhoefel G. ; Kučera M.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 487 起始页码: 138
结束页码: 150
语种: 英语
英文关键词: boron isotopes
; planktonic foraminifera
; seasonality
Scopus关键词: Alkalinity
; Biomineralization
; Boron
; Calcite
; Cooling systems
; Ecosystems
; Electromagnetic induction
; Isotopes
; Mass spectrometers
; Mass spectrometry
; Boron isotopes
; Foraminiferal shells
; Habitat preferences
; Inductively coupled mass spectrometries
; Isotopic composition
; Multispecies approach
; Planktonic foraminifera
; Seasonality
; Surface waters
; boron isotope
; habitat selection
; isotopic composition
; paleoenvironment
; pH
; planktonic foraminifera
; reconstruction
; seasonality
; Atlantic Ocean
; Atlantic Ocean (Southeast)
; Foraminifera
; Globigerina bulloides
; Globigerinoides ruber
; Orbulina universa
英文摘要: The boron isotopic composition of planktonic foraminiferal shell calcite (δ11BCc) provides valuable information on the pH of ambient water at the time of calcification. Hence, δ11BCc of fossil surface-dwelling planktonic foraminifera can be used to reconstruct ancient aqueous pCO2 if information on a second carbonate system parameter, temperature and salinity is available. However, pH and pCO2 of surface waters may vary seasonally, largely due to changes in temperature, DIC, and alkalinity. As also the shell fluxes of planktonic foraminifera show species-specific seasonal patterns that are linked to intra-annual changes in temperature, it is obvious that δ11BCc of a certain species reflects the pH and thus pCO2 biased towards a specific time period within a year. This is important to consider for the interpretation of fossil δ11BCc records that may mirror seasonal pH signals. Here we present new Multi-Collector Inductively Coupled Mass Spectrometry (MC-ICPMS) δ11BCc coretop data for the planktonic foraminifera species Globigerina bulloides, Globigerinoides ruber, Trilobatus sacculifer and Orbulina universa and compare them with δ11Bborate derived from seasonally resolved carbonate system parameters. We show that the inferred season-adjusted δ11BCc/δ11Bborate relationships are similar to existing calibrations and can be combined with published δ11BCc field and culture data to augment paleo-pH calibrations. To test the applicability of these calibrations, we used a core drilled on the Walvis Ridge in the Southeast Atlantic spanning the last 330,000 years to reconstruct changes in surface-water pCO2. The reconstruction based on G. bulloides, which reflects the austral spring season, was shown to yield values that closely resemble the Vostok ice-core data indicating that surface-water pCO2 was close to equilibrium with the atmosphere during the cooler spring season. In contrast, pCO2 estimated from δ11BCc of O. universa, T. sacculifer and G. ruber that predominantly lived during the warmer seasons, exhibits up to ∼50 ppmv higher values than the Vostok ice-core data. This is probably due to the higher austral summer and fall temperatures, as shown by Mg/Ca to be on average ∼4 °C higher than during the cooler spring season, accounting for an increase in pCO2 of ∼4% per 1 °C. Our results demonstrate that paleo-pH estimates based on δ11BCc contain a significant seasonal signal reflecting the habitat preference of the recording foraminifera species. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110008
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: MARUM – Zentrum für Marine Umweltwissenschaften, Universität Bremen, Leobener Straße, Bremen, 28359, Germany; Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Handelshafen 12, Bremerhaven, 27570, Germany; Leibniz-Universität Hannover, Institut für Mineralogie, Callinstraße 3, Hannover, 30167, Germany
Recommended Citation:
Raitzsch M.,Bijma J.,Benthien A.,et al. Boron isotope-based seasonal paleo-pH reconstruction for the Southeast Atlantic – A multispecies approach using habitat preference of planktonic foraminifera[J]. Earth and Planetary Science Letters,2018-01-01,487