Abstract
The major control upon abundance of planktonic foraminifera and their stable oxygen isotope (δ 18 O) signature is the seasonally linked variation in water hydrography, key to the proliferation or attenuation of ecologically beneficial constraints. The range and variance σ(δ 18 O) of planktonic foraminifera can reflect changes in either the season or depth of calcification. For a detailed reconstruction of ocean changes we employed multispecies single-specimen analysis, which allows extraction of the isotopic variability within the species for the time covered by the sample. Previous studies with pooled specimens have shown that the multiannual temperature range may be extracted. Here we investigate how seasonality can be deduced from single-specimen analysis of planktonic foraminifera combined with multiple other proxies (IRD percent, faunal abundance) from Termination III. Our single-shell isotope results show that the variance in Globigerina bulloides oxygen isotope values corresponds to the insolation at the core site. Furthermore, faunal and isotopic analyses of the polar-subpolar neogloboquadrinid species, N. pachyderma (NPS) and N. incompta, reveal an intriguing result. These species are sister taxa, representing genetically distinct species, whose relative abundance reflects warm and cold conditions. While the difference between their isotopic means should reflect the temperature difference between their distinct growing seasons, we show that this difference also has a statistically significant relationship with the spread in individual NPS δ 18 O. At an appropriate core site, this approach could be used to further constrain the length of the growing season and therefore the inherent variability recorded within proxy records.
| Original language | English |
|---|---|
| Pages (from-to) | 374-393 |
| Number of pages | 20 |
| Journal | Paleoceanography and Paleoclimatology |
| Volume | 34 |
| Issue number | 3 |
| Early online date | 8 Feb 2019 |
| DOIs | |
| Publication status | Published - Mar 2019 |
Fingerprint
Keywords
- individual foraminiferal analysis
- planktonic foraminifera
- seasonality
- single-shell analysis
- stable isotopes
- Termination III
Cite this
}
Oxygen isotope variability of planktonic foraminifera provide clues to past upper ocean seasonal variability. / Metcalfe, Brett; Feldmeijer, Wouter; Ganssen, Gerald M.
In: Paleoceanography and Paleoclimatology, Vol. 34, No. 3, 03.2019, p. 374-393.Research output: Contribution to Journal › Article › Academic › peer-review
TY - JOUR
T1 - Oxygen isotope variability of planktonic foraminifera provide clues to past upper ocean seasonal variability
AU - Metcalfe, Brett
AU - Feldmeijer, Wouter
AU - Ganssen, Gerald M.
PY - 2019/3
Y1 - 2019/3
N2 - The major control upon abundance of planktonic foraminifera and their stable oxygen isotope (δ 18 O) signature is the seasonally linked variation in water hydrography, key to the proliferation or attenuation of ecologically beneficial constraints. The range and variance σ(δ 18 O) of planktonic foraminifera can reflect changes in either the season or depth of calcification. For a detailed reconstruction of ocean changes we employed multispecies single-specimen analysis, which allows extraction of the isotopic variability within the species for the time covered by the sample. Previous studies with pooled specimens have shown that the multiannual temperature range may be extracted. Here we investigate how seasonality can be deduced from single-specimen analysis of planktonic foraminifera combined with multiple other proxies (IRD percent, faunal abundance) from Termination III. Our single-shell isotope results show that the variance in Globigerina bulloides oxygen isotope values corresponds to the insolation at the core site. Furthermore, faunal and isotopic analyses of the polar-subpolar neogloboquadrinid species, N. pachyderma (NPS) and N. incompta, reveal an intriguing result. These species are sister taxa, representing genetically distinct species, whose relative abundance reflects warm and cold conditions. While the difference between their isotopic means should reflect the temperature difference between their distinct growing seasons, we show that this difference also has a statistically significant relationship with the spread in individual NPS δ 18 O. At an appropriate core site, this approach could be used to further constrain the length of the growing season and therefore the inherent variability recorded within proxy records.
AB - The major control upon abundance of planktonic foraminifera and their stable oxygen isotope (δ 18 O) signature is the seasonally linked variation in water hydrography, key to the proliferation or attenuation of ecologically beneficial constraints. The range and variance σ(δ 18 O) of planktonic foraminifera can reflect changes in either the season or depth of calcification. For a detailed reconstruction of ocean changes we employed multispecies single-specimen analysis, which allows extraction of the isotopic variability within the species for the time covered by the sample. Previous studies with pooled specimens have shown that the multiannual temperature range may be extracted. Here we investigate how seasonality can be deduced from single-specimen analysis of planktonic foraminifera combined with multiple other proxies (IRD percent, faunal abundance) from Termination III. Our single-shell isotope results show that the variance in Globigerina bulloides oxygen isotope values corresponds to the insolation at the core site. Furthermore, faunal and isotopic analyses of the polar-subpolar neogloboquadrinid species, N. pachyderma (NPS) and N. incompta, reveal an intriguing result. These species are sister taxa, representing genetically distinct species, whose relative abundance reflects warm and cold conditions. While the difference between their isotopic means should reflect the temperature difference between their distinct growing seasons, we show that this difference also has a statistically significant relationship with the spread in individual NPS δ 18 O. At an appropriate core site, this approach could be used to further constrain the length of the growing season and therefore the inherent variability recorded within proxy records.
KW - individual foraminiferal analysis
KW - planktonic foraminifera
KW - seasonality
KW - single-shell analysis
KW - stable isotopes
KW - Termination III
UR - http://www.scopus.com/inward/record.url?scp=85063336229&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85063336229&partnerID=8YFLogxK
U2 - 10.1029/2018PA003475
DO - 10.1029/2018PA003475
M3 - Article
VL - 34
SP - 374
EP - 393
JO - Paleoceanography and Paleoclimatology
JF - Paleoceanography and Paleoclimatology
SN - 2572-4517
IS - 3
ER -