d18O_model {ShellChron}

Function to convert SST data to d18O

Description

Takes a matrix of SST data (in degrees C) against time (in days), information about the d18O value (in permille VSMOW) of the water and how it changes through the year and the transfer function used for of the record (e.g. Kim and O'Neil, 1997 or Grossman and Ku, 1986). Converts the SST data to d18O data using the supplied empirical transfer function.

Usage

d18O_model(SST, d18Ow = 0, transfer_function = "KimONeil97")

Arguments

SST

Matrix with a time column (values in days) and an SST column (values in degrees C)

d18Ow

Either a single value (constant d18Ow) or a vector of length equal to the period in SST data (365 days by default) containing information about seasonality in d18Ow. Defaults to constant d18Ow of 0 permille VSMOW (the modern mean ocean value)

transfer_function

String containing the name of the transfer function (for example: "KimONeil97" or "GrossmanKu86"). Defaults to Kim and O'Neil (1997).

Value

A vector containing d18O values for each SST value in "SST"

References

Grossman, E.L., Ku, T., Oxygen and carbon isotope fractionation in biogenic aragonite: temperature effects, Chemical Geology 1986, 59.1, 59-74. doi: 10.1016/0168-9622(86)90057-6 Kim, S., O'Niel, J.R., Equilibrium and nonequilibrium oxygen isotope effects in synthetic carbonates, Geochimica et Cosmochimica Acta 1997, 61.16, 3461-3475. doi: 10.1016/S0016-7037(97)00169-5 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. doi: 10.1016/S0016-7037(99)00020-4 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. doi: 10.1515/pac-2013-1023

Examples

# Create dummy SST data
t <- seq(1, 40, 1)
T <- sin((2 * pi * (seq(1, 40, 1) - 8 + 10 / 4)) / 10)
SST <- cbind(t, T)
# Run d18O model function
d18O <- d18O_model(SST, 0, "KimONeil97")