
Development of a regional glycerol dialkyl glycerol tetraether (GDGT)-temperature calibration for Antarctic and sub-Antarctic lakes
- Author
- Louise C. Foster, Emma J. Pearson, Steve Juggins, Dominic A. Hodgson, Krystyna M. Saunders, Elie Verleyen (UGent) and Stephen J. Roberts
- Organization
- Abstract
- A regional network of quantitative reconstructions of past climate variability is required to test climate models. In recent studies, temperature calibration models based on the relative abundances of sedimentary glycerol dialkyl glycerol tetraethers (GDGTs) have enabled past temperature reconstructions in both marine and terrestrial environments. Nevertheless, to date these methods have not been widely applied in high latitude environments due to poor performance of the GDGT–temperature calibrations at lower temperatures. To address this we studied 32 lakes from Antarctica, the sub-Antarctic Islands and Southern Chile to: 1) quantify their GDGT composition and investigate the environmental controls on GDGT composition; and 2) develop a GDGT–temperature calibration model for inferring past temperatures from Antarctic and sub-Antarctic lakes. GDGTs were found in all 32 lakes studied and in 31 lakes branched GDGTs (brGDGTs) were the dominant compounds. Statistical analyses of brGDGT composition in relation to temperature, pH, conductivity and water depth showed that the composition of brGDGTs is strongly correlated with mean summer air temperature (MSAT). This enabled the development of the first regional brGDGT–temperature calibration for use in Antarctic and sub-Antarctic lakes using four brGDGT compounds (GDGT-Ib, GDGT-II, GDGT-III and GDGT-IIIb). A key discovery was that GDGT-IIIb is of particular importance in cold lacustrine environments. The addition of this compound significantly improved the model's performance from , RMSEP-LOO (leave-one-out) = 2.23 °C, RMSEP-H (h-block) = 2.37 °C when applying the re-calibrated global GDGT–temperature calibration to our Antarctic dataset to , RMSEP-LOO = 1.68 °C, RMSEP-H = 1.65 °C for our new Antarctic calibration. This shows that Antarctic and sub-Antarctic, and possibly other high latitude, palaeotemperature reconstructions should be based on a regional GDGT–temperature calibration where specific compounds can be identified and included to improve model performance. Finally, downcore temperature reconstructions using the new Antarctic brGDGT–temperature calibration were tested in sub-Antarctic Fan Lake from South Georgia providing a proof of concept for the new calibration model in the Southern Hemisphere.
- Keywords
- palaeoclimate, temperature reconstruction, GDGTs, Southern Hemisphere, Antarctic, palaeolimnology, CRENARCHAEOTAL MEMBRANE-LIPIDS, GDGT-BASED PROXIES, VI ICE SHELF, HOLOCENE CLIMATE, AFRICAN LAKE, TEMPERATURE VARIABILITY, PALEOTEMPERATURE PROXY, ENVIRONMENTAL CONTROLS, WATER TEMPERATURES, EAST ANTARCTICA
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Citation
Please use this url to cite or link to this publication: http://hdl.handle.net/1854/LU-7244489
- MLA
- Foster, Louise C., et al. “Development of a Regional Glycerol Dialkyl Glycerol Tetraether (GDGT)-Temperature Calibration for Antarctic and Sub-Antarctic Lakes.” EARTH AND PLANETARY SCIENCE LETTERS, vol. 433, 2016, pp. 370–79, doi:10.1016/j.epsl.2015.11.018.
- APA
- Foster, L. C., Pearson, E. J., Juggins, S., Hodgson, D. A., Saunders, K. M., Verleyen, E., & Roberts, S. J. (2016). Development of a regional glycerol dialkyl glycerol tetraether (GDGT)-temperature calibration for Antarctic and sub-Antarctic lakes. EARTH AND PLANETARY SCIENCE LETTERS, 433, 370–379. https://doi.org/10.1016/j.epsl.2015.11.018
- Chicago author-date
- Foster, Louise C., Emma J. Pearson, Steve Juggins, Dominic A. Hodgson, Krystyna M. Saunders, Elie Verleyen, and Stephen J. Roberts. 2016. “Development of a Regional Glycerol Dialkyl Glycerol Tetraether (GDGT)-Temperature Calibration for Antarctic and Sub-Antarctic Lakes.” EARTH AND PLANETARY SCIENCE LETTERS 433: 370–79. https://doi.org/10.1016/j.epsl.2015.11.018.
- Chicago author-date (all authors)
- Foster, Louise C., Emma J. Pearson, Steve Juggins, Dominic A. Hodgson, Krystyna M. Saunders, Elie Verleyen, and Stephen J. Roberts. 2016. “Development of a Regional Glycerol Dialkyl Glycerol Tetraether (GDGT)-Temperature Calibration for Antarctic and Sub-Antarctic Lakes.” EARTH AND PLANETARY SCIENCE LETTERS 433: 370–379. doi:10.1016/j.epsl.2015.11.018.
- Vancouver
- 1.Foster LC, Pearson EJ, Juggins S, Hodgson DA, Saunders KM, Verleyen E, et al. Development of a regional glycerol dialkyl glycerol tetraether (GDGT)-temperature calibration for Antarctic and sub-Antarctic lakes. EARTH AND PLANETARY SCIENCE LETTERS. 2016;433:370–9.
- IEEE
- [1]L. C. Foster et al., “Development of a regional glycerol dialkyl glycerol tetraether (GDGT)-temperature calibration for Antarctic and sub-Antarctic lakes,” EARTH AND PLANETARY SCIENCE LETTERS, vol. 433, pp. 370–379, 2016.
@article{7244489, abstract = {{A regional network of quantitative reconstructions of past climate variability is required to test climate models. In recent studies, temperature calibration models based on the relative abundances of sedimentary glycerol dialkyl glycerol tetraethers (GDGTs) have enabled past temperature reconstructions in both marine and terrestrial environments. Nevertheless, to date these methods have not been widely applied in high latitude environments due to poor performance of the GDGT–temperature calibrations at lower temperatures. To address this we studied 32 lakes from Antarctica, the sub-Antarctic Islands and Southern Chile to: 1) quantify their GDGT composition and investigate the environmental controls on GDGT composition; and 2) develop a GDGT–temperature calibration model for inferring past temperatures from Antarctic and sub-Antarctic lakes. GDGTs were found in all 32 lakes studied and in 31 lakes branched GDGTs (brGDGTs) were the dominant compounds. Statistical analyses of brGDGT composition in relation to temperature, pH, conductivity and water depth showed that the composition of brGDGTs is strongly correlated with mean summer air temperature (MSAT). This enabled the development of the first regional brGDGT–temperature calibration for use in Antarctic and sub-Antarctic lakes using four brGDGT compounds (GDGT-Ib, GDGT-II, GDGT-III and GDGT-IIIb). A key discovery was that GDGT-IIIb is of particular importance in cold lacustrine environments. The addition of this compound significantly improved the model's performance from , RMSEP-LOO (leave-one-out) = 2.23 °C, RMSEP-H (h-block) = 2.37 °C when applying the re-calibrated global GDGT–temperature calibration to our Antarctic dataset to , RMSEP-LOO = 1.68 °C, RMSEP-H = 1.65 °C for our new Antarctic calibration. This shows that Antarctic and sub-Antarctic, and possibly other high latitude, palaeotemperature reconstructions should be based on a regional GDGT–temperature calibration where specific compounds can be identified and included to improve model performance. Finally, downcore temperature reconstructions using the new Antarctic brGDGT–temperature calibration were tested in sub-Antarctic Fan Lake from South Georgia providing a proof of concept for the new calibration model in the Southern Hemisphere.}}, author = {{Foster, Louise C. and Pearson, Emma J. and Juggins, Steve and Hodgson, Dominic A. and Saunders, Krystyna M. and Verleyen, Elie and Roberts, Stephen J.}}, issn = {{0012-821X}}, journal = {{EARTH AND PLANETARY SCIENCE LETTERS}}, keywords = {{palaeoclimate,temperature reconstruction,GDGTs,Southern Hemisphere,Antarctic,palaeolimnology,CRENARCHAEOTAL MEMBRANE-LIPIDS,GDGT-BASED PROXIES,VI ICE SHELF,HOLOCENE CLIMATE,AFRICAN LAKE,TEMPERATURE VARIABILITY,PALEOTEMPERATURE PROXY,ENVIRONMENTAL CONTROLS,WATER TEMPERATURES,EAST ANTARCTICA}}, language = {{eng}}, pages = {{370--379}}, title = {{Development of a regional glycerol dialkyl glycerol tetraether (GDGT)-temperature calibration for Antarctic and sub-Antarctic lakes}}, url = {{http://doi.org/10.1016/j.epsl.2015.11.018}}, volume = {{433}}, year = {{2016}}, }
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