Status of palaeoceanographic transfer functions

A wide variety of microfossil groups have been used to generate quantitative reconstructions of palaeoceanographic conditions. This post lists the species groups used, the variables reconstructed with them, with some comments on the availability of the data.

This list is probably not comprehensive, please let me know if someone is reconstructing a variable, or using an organism group, that I have missed. Transfer functions for coastal environments (for example sea-level or coastal eutrophication) are omitted.

Coccoliths

There does not seem to be much recent work developing transfer functions for coccoliths, the small calcareous plates that make up the cell walls of coccolithophores. Giraudeau & Beaufort (2007) have some suggestions why.

Diatoms

Diatom, siliceous algae identifiable to species level from ornamentation on their valves, have been used for palaeoceanographic reconstructions by several authors.

De Sève (1999) published a calibration set from the Labrador Sea for reconstructing SST and salinity in February and August using Imbrie and Kipp factor analysis. I strongly doubt there is robust evidence for all four calibration functions. February SST seems dubious as there is little growth then, and salinity transfer functions for the salinity range 30-35 psu need supporting evidence to show that diatoms actually respond to salinity over this range.

A diatom-SST calibration set off Iceland was published by Jiang et al (2001) and developed into a WAPLS transfer function by Jiang et al (2005). Both summer and winter SST is reconstructed, the latter is dubious. The calibration-set data are included as an appendix to Jiang et al (2001).

The Tromso group led by Nalan Koç have developed diatom SST (Andersen et al 2004; 52 observations) and sea-ice (Justwan & Koç, 2008; 99 observations) transfer functions for the Nordic Seas.

The North Atlantic diatom calibration sets do not appear to have been combined. Perhaps taxonomic differences prevent this, perhaps there are other issues.

Working in the north east Pacific, Lopes et al (2010) have published a diatom-productivity transfer function, which I find credible, and a diatom-seasonality transfer function, which I find doubtful.

Calibration sets for the Southern Ocean have been published by Crosta et al (1998) (summer-SST, months of sea-ice cover), and Zielinski et al (1998) (summer SST).

Organic-walled Dinocysts

Anne de Vernal and co-workers have published several versions of a Northern Hemisphere dinocyst calibration set, each about 300 observations larger than the previous. Transfer functions have been developed for SST and salinity (de Vernal et al 2005); productivity (Radi & de vernal 2008); and sea ice (de Vernal et al 2013). These variables are reconstructed for both summer and winter. The calibration data are available from geotops.ca. Some of these dinocyst transfer functions are very dubious, as I’ve discussed elsewhere, and on this blog.

Calcareous Dinocysts

About 30 species of extant dinoflagellates produce calcareous cysts. Data sets have been generated by Vink (2004) for the South Atlantic and Richter et al (2007) for the upwelling areas of NW Africa, but transfer functions have not been developed. Data from Vink (2004) are archived at pangaea.de.

Benthic Foraminifera

Benthic foraminifera have been widely used to reconstruct sea-level, but have also been used away from the coastline. For example Sejrup et al (2004) developed transfer functions for benthic temperature and salinity in Nordic Seas. Given the short, 33.5-35.5 psu, salinity gradient, I think the salinity transfer function is doubtful. The calibration-set data are in an appendix to the paper.

Planktonic Foraminifera

Planktonic foraminifera have been widely used for quantitative palaeoenvironmental reconstructions since the early 1970s. The usual practice is to develop calibration sets for each ocean basin to try to minimise problems with cryptic taxa. MARGO with an associated issue of QSR is the most recent publication of the calibration sets (additional samples are available from some areas). According to Morley et al (2005)

Planktonic foraminifera preserved in deep-sea sediments have been used to estimate sea-surface temperature (Imbrie and Kipp, 1971; Kipp, 1976), primary production (Mix, 1989), annual temperature as a function of mixed-layer depth in the tropical Atlantic (Ravelo et al., 1990), thermocline depth in the tropical Pacific (Andreasen and Ravelo, 1997) and carbonate-ion saturation at the seafloor (Anderson and Archer, 2002).

Some of these are probably reasonable, at least in some areas, others are more dubious.

Radiolarians

Haeckel 1904

Radiolarians are siliceous zooplankton related to the foraminifera. Pisias et al (1997) publish a Pacific radiolarian calibration set and develop transfer functions using Imbrie and Kipp factor analysis for mean annual SST and SST seasonality. The latter is more dubious. Data are archived.

Abelmann et al (1999) show a summer-SST radiolarian transfer function for the Atlantic sector of the Southern Ocean, using Imbrie and Kipp factor analysis.

Cortese et al (2003) report a summer-SST radiolarian transfer function from the Nordic Seas using Imbrie and Kipp factor analysis. They report that the data are archived at pangaea.de, but I cannot locate them.

Silicoflagellates

Silicoflagellates are not sufficiently diverse in the modern ocean to support a transfer function, but they are sometimes included in the diatom transfer functions.

Summary

Some authors (mainly working in high latitudes) are explicit that they are only attempting to reconstruct summer SST as this is what they think is ecologically reasonable given the season of production and the ecology of the organisms. Others seem to try to reconstruct any environmental variable they can find, and because the calibration sets are spatially autocorrelated, they will normally appear to be successful. Many of the more exotic variables reconstructed do not seem to be widely used after the initial application.

Sometimes it is not clear exactly what is being reconstructed. SST – which season, what depth, which data source – it shouldn’t be too hard to include this information.

Several groups try to reconstruct salinity, a very important oceanographic variable, from microfossil assemblages. This might work in coastal environments where there is an long salinity gradient, but I am doubtful that many organisms are particularly sensitive to salinity differences in the range 30-35 psu. They might appear sensitive either because of spatial autocorrelation or because salinity is correlated with some variable the species do care about, for example food supply. If this correlation is not stable over time, reconstructions will be risky.

References

Abelmann, A, Brathauer, U, Gersonde, R, Sieger, R & Zielinski, U (1999) Radiolarian-based transfer function for the estimation of sea surface temperatures in the Southern Ocean (Atlantic Sector). Paleoceanography 14: 410-421

Andersen, C, Koç, N, Jennings, A & Andrews, JT (2004) Nonuniform response of the major surface currents in the Nordic Seas to insolation forcing: Implications for the Holocene climate variability. Paleoceanography 19: PA2003

Cortese G, Bjørklund KR, Dolven JK. (2003) Polycystine radiolarians in the Greenland–Iceland–Norwegian Seas: species and assemblage distribution. Sarsia 88:65–88

Crosta, X, Pichon, J.-J. & Burckle, L. H (1998) Application of modern analog technique to marine Antarctic diatoms: Reconstruction of maximum sea-ice extent at the Last Glacial Maximum. Paleoceanography, 13: 284-297

De Sève, MA (1999) Transfer function between surface sediment diatom assemblages and sea-surface temperature and salinity of the Labrador Sea.Marine Micropaleontology36, 249–267

de Vernal, A., Eynaud, F., Henry, M., Hillaire-Marcel, C., Londeix, L., Mangin, S., Matthiessen, J., Marret, F., Radi, T., Rochon, A., Solignac, S., Turon, J.-L., (2005) Reconstruction of sea-surface conditions at middle to high latitudes of the Northern Hemisphere during the Last Glacial Maximum (LGM) based on dinoflagellate cyst assemblages, Quaternary Science Reviews, 24: 897-924

de Vernal, A, Rochon, A, Fréchette, B, Henry, M, Radi, T & Solignac, S (2013) Reconstructing past sea ice cover of the Northern Hemisphere from dinocyst assemblages: status of the approach. Quaternary Science Reviews

Jiang, H., Seidenkrantz, M.-S., Knudsen, K.L., & Eiríksson, J. (2001) Diatom surface sediment assemblages around Iceland and their relationships to oceanic environmental variables. Marine Micropaleontology, 41: 73-96

Jiang, J, Eiriksson, J, Schulz, M, Knudsen, KL & Seidenkrantz MS (2005) Evidence for solar forcing of sea-surface temperature on the North Icelandic Shelf during the late Holocene. Geology, 33: 73-76

Justwan, A & Koç, N (2008) A diatom based transfer function for reconstructing sea ice concentrations in the North Atlantic. Marine Micropaleontology, 66: 264–278

Pisias, NG, Roelofs, A & Weber, M (1997) Radiolarian-based transfer functions for estimating mean surface ocean temperatures and seasonal range. Paleoceanography 12: 365-379

Radi, T & de Vernal, A (2008) Dinocysts as proxy of primary productivity in mid-high latitudes of the Northern Hemisphere, Marine Micropaleontology, 68, 84-114

Richter, D, Vink, A, Zonneveld, KAF, Kuhlmann H & Willems, H (2007) Calcareous dinoflagellate cyst distributions in surface sediments from upwelling areas off NW Africa, and their relationships with environmental parameters of the upper water column. Marine Micropaleontology 63, 201–228

Sejrup, HP,  Birks, HJB, Klitgaard Kristensen, D & Madsen H (2004) Benthonic foraminiferal distributions and quantitative transfer functions for the northwest European continental margin. Marine Micropaleontology, 53: 197–226 http://dx.doi.org/10.1016/j.marmicro.2004.05.009

Vink, A., 2004. Calcareous dinoflagellate cysts in South and equatorial Atlantic surface sediments: diversity, distribution, ecology and potential for palaeoenvironmental reconstruction. Marine Micropaleontology 50, 43–88

Zielinski, U, Gersonde, R, Sieger, R & Fütterer, D. (1998) Quaternary surface water temperature estimations: Calibration of a diatom transfer function for the Southern Ocean Paleoceanography,13: 365-383

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About richard telford

Ecologist with interests in quantitative methods and palaeoenvironments
This entry was posted in climate, Peer reviewed literature, transfer function and tagged , , , , . Bookmark the permalink.

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