BODC volume to mass conversion factor
The parameter TOKGPR01 is provided to enable the conversion of data from units per litre to units per kilogram. It is supplied as a standardised conversion factor and may not necessarily be the same as that used by the data originator, which is not always provided. BODC store this conversion factor to enable the derivation of comparable datasets when units are not equivalent. TOKGPR01 was calculated by BODC as follows:
TOKGPR01 = 1000/(sigmaθ+1000)
Where sigmaθ = potential density based on salinity, potential temperature and a reference pressure of 0db (Fofonoff and Millard, 1983). Salinity and temperature data used in this calculation were obtained by BODC software that extracts calibrated CTD downcast data (or upcast data if the downcast is unavailable) at depths corresponding to those at which the bottles were fired. CTD data used in this calculation are also available from BODC.
| Parameter | Units | Description |
|---|---|---|
| TOKGPR01 | L/kg | Conversion factor (volume to mass) for the water body by CTD and computation of density (in-situ potential temperature surface pressure) reciprocal from pressure, temperature and salinity |
Reference
Fofonoff, N.P. and Millard Jr., R.C., 1983. Algorithms for computations of fundamental properties of seawater, UNESCO Technical Papers in Marine Science, 44, 53.
