optimization_seasonality: Function for sample size optimization based clumped isotope...

In seasonalclumped: Toolbox for Clumped Isotope Seasonality Reconstructions

Description

Combines records of stable oxygen isotope ratios (δ18Oc) and clumped isotope ratios (Δ47) through subannually resolved carbonate archives (e.g. mollusk shells or corals) to reconstruct monthly variability in temperature and salinity (through the δ18O composition of the precipitation fluid), using the sample size optimization method detailed in de Winter et al., 2020 (Climate of the Past).

Usage

optimization_seasonality(
  d18Oc,
  D47,
  ages,
  SD_d18Oc = 0.1,
  SD_D47 = 0.04,
  N = 1000,
  p = 0.05,
  d18O_fun = "KimONeil97",
  D47_fun = "Bernasconi18",
  export = FALSE,
  export_raw = FALSE
)

Arguments

d18Oc	Vector containing subannually resolved δ18Oc data
D47	Vector containing subannually resolved Δ47 data
ages	Vector containing ages for of all samples in years relative to the shell chronology
SD_d18Oc	Error on the δ18Oc measurements. Either a single value (constant uncertainty) or a vector of length equal to the period in SST data (365 days by default) containing information about the error of each datapoint (1 standard deviation; default = 0.1 permille).
SD_D47	Error on the Δ47 measurements. Either a single value (constant uncertainty) or a vector of length equal to the period in SST data (365 days by default) containing information about the error of each datapoint (1 standard deviation; default = 0.04 permille).
N	Number of datapoints for Monte Carlo simulation (defaults to 1000)
p	Threshold value for the p value of separating summer from winter reconstructions. Defaults to 0.05 (95% confidence level)
d18O_fun	String containing the name of the transfer function used to convert temperature and δ18Ow to δ18Oc data (for example: "KimONeil97" or "GrossmanKu86"). Defaults to Kim and O'Neil (1997).
D47_fun	String containing the name of the transfer function used to convert temperature to Δ47 data (for example: "Bernasconi18" or "Jautzy20"). Defaults to Bernasconi et al., 2018).
export	Export table summary of result (CSV format)? TRUE/FALSE
export_raw	Export tables containing all raw model results before being merged into tidy tables? TRUE/FALSE

Value

A data frame containing monthly reconstructions of Δ47, temperature, δ18O of the precipitation fluid and δ18Oc.

References

package dependencies: TTR Grossman, E.L., Ku, T., Oxygen and carbon isotope fractionation in biogenic aragonite: temperature effects, Chemical Geology 1986, 59.1, 59–74. https://doi.org/bvpzws

Kim, S., O'Niel, J.R., Equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates, Geochimica et Cosmochimica Acta 1997, 61.16, 3461–3475. https://doi.org/c7bwbp

Dettman, D.L., Reische, A.K., Lohmann, K.C., Controls on the stable isotope composition of seasonal growth bands in aragonitic fresh–water bivalves (Unionidae), Geochimica et Cosmochimica Acta 1999, 63.7–8, 1049–1057. https://doi.org/cbb7zc

Brand, W.A., Coplen, T.B., Vogl, J., Rosner, M., Prohaska, T., Assessment of international reference materials for isotope–ratio analysis (IUPAC Technical Report), Pure and Applied Chemistry 2014, 86.3, 425–467. https://doi.org/fpc2

Kele, S., Breitenbach, S. F., Capezzuoli, E., Meckler, A. N., Ziegler, M., Millan, I. M., Kluge, T., Deák, J., Hanselmann, K. and John, C. M., Temperature dependence of oxygen– and clumped isotope fractionation in carbonates: a study of travertines and tufas in the 6–95 C temperature range, Geochimica et Cosmochimica Acta 2015, 168, 172–192. https://doi.org/f7sgn6

Bernasconi, S.M., Müller, I.A., Bergmann, K.D., Breitenbach, S.F., Fernandez, A., Hodell, D.A., Jaggi, M., Meckler, A.N., Millan, I. and Ziegler, M., Reducing uncertainties in carbonate–clumped isotope analysis through consistent carbonate based standardization. Geochemistry, Geophysics, Geosystems 2018, 19–9, 2895–2914. https://doi.org/gfmjrw

Petersen, S. V., Defliese, W. F., Saenger, C., Daëron, M., Huntington, K. W., John, C. M., Kelson, J. R., Bernasconi, S. M., Colman, A. S., Kluge, T., Olack, G. A., Schauer, A. J., Bajnai, D., Bonifacie, M., Breitenbach, S. F. M., Fiebig, J., Fernandez, A. B., Henkes, G. A., Hodell, D., Katz, A., Kele, S., Lohmann, K. C., Passey, B. H., Peral, M. Y., Petrizzo, D. A., Rosenheim, B. E., Tripati, A., Venturelli, R., Young, E. D. and Winkelstern, I. Z., Effects of Improved 17O Correction on Interlaboratory Agreement in Clumped Isotope Calibrations, Estimates of Mineral–Specific Offsets, and Temperature Dependence of Acid Digestion Fractionation, Geochemistry, Geophysics, Geosystems *2019, 20–7, 3495–3519. https://doi.org/ggrc39

Jautzy, J. J., Savard, M. M., Dhillon, R. S., Bernasconi, S. M. and Smirnoff, A., Clumped isotope temperature calibration for calcite: Bridging theory and experimentation, Geochemical Perspectives Letters 2020, 14, 36–41. https://doi.org/fpc3

de Winter, N. J., Agterhuis, T., Ziegler, M., Optimizing sampling strategies in high–resolution paleoclimate records, Climate of the Past Discussions 2020, 1–52. https://doi.org/fpc4

Examples

# find attached dummy data
Case1 <- seasonalclumped::Case1
d18Oc <- Case1[, 29]
d18Oc <- d18Oc[-which(is.na(d18Oc))]
D47 <- Case1[, 30]
D47 <- D47[-which(is.na(D47))]
ages <- Case1[, 27]
ages <- ages[-which(is.na(ages))]
# Run function
monthly <- optimization_seasonality(d18Oc = d18Oc,
D47 = D47,
ages = ages,
SD_d18Oc = 0.1,
SD_D47 = 0.04,
N = 100, # Use small amount of samples for quick testing (recommended N = 1000)
p = 0.05,
d18O_fun = "KimONeil97",
D47_fun = "Bernasconi18",
export = FALSE,
export_raw = FALSE)

seasonalclumped documentation built on Jan. 16, 2021, 5:26 p.m.