marelac: Tools for Aquatic Sciences

marelac-packageR Documentation

Tools for Aquatic Sciences


R-package marelac has been designed as a tool for use by scientists working in the MArine, Riverine, Estuarine, LAcustrine and Coastal sciences.

It contains:

  • chemical and physical constants, e.g. atomic weights, gas constants.

  • conversion factors, e.g. from salinity to chlorinity, from mol to gram, etc.,

  • utility functions, e.g. to estimate concentrations of conservative substances as a function of salinity, ...

About the symbols used.

Here we adopt the symbolism as in McDougall et al., 2009:

  • S for practical (-) or absolute salinity, (g/kg)

  • P for absolute (total) pressure (bar)

  • p for sea pressure (also called gauge or applied pressure (bar), the pressure relative to P0, one standard atmosphere (=1.01325 bar)

  • t for temperature in ^\circC

  • T for absolute temperature, in ^\circK; T = t + 273.15

Many of the functions are from the UNESCO 1983 paper, or from Feistel, 2008. Note that in these papers, pressure is expressed in dbar.


Karline Soetaert (Maintainer)

Thomas Petzoldt

with contributions from Lorenz Meire and Filip Meysman


For solubilities, atmospheric composition, gas exchange coefficients:

Sarmiento JL and Gruber N, 2006. Ocean Biogeochemical Dynamics. Princeton University Press, Princeton. p 85.

For diffusion coefficients, viscosity

Boudreau BP, 1996. A method-of-lines code for carbon and nutrient diagenesis in aquatic sediments. Computers & Geosciences 22 (5), 479-496.

For many other fundamental properties of seawater, either the UNESCO report (1983):

Fofonoff NP and Millard RC Jr, 1983. Algorithms for computation of fundamental properties of seawater. UNESCO technical papers in marine science, 44, 53 pp.

or the more recent report and papers:

Feistel R, 2008. A Gibbs function for seawater thermodynamics for -6 to 80 dgC and salinity up to 120 g/kg. Deep-Sea Research I, 55, 1639-1671.

McDougall TJ, Feistel R, Millero FJ, Jackett DR, Wright DG, King BA, Marion GM, Chen C-T A and Spitzer P, 2009. Calculation of the Thermophysical Properties of Seawater, Global Ship-based Repeat Hydrography Manual, IOCCP Report No. 14, ICPO Publication Series no. 134.

Millero FJ, Feistel R, Wright DG, and McDougall TJ, 2008. The composition of Standard Seawater and the definition of the Reference-Composition Salinity Scale, Deep-Sea Res. I, 55, 50-72.

See Also

for seawater properties:

sw_adtgrad, sw_alpha, sw_beta, sw_comp, sw_conserv, sw_cp, sw_dens, sw_depth, sw_enthalpy, sw_entropy, sw_gibbs, sw_kappa, sw_kappa_t, sw_sfac, sw_svel, sw_tfreeze, sw_tpot

for atmospheric gasses:

gas_satconc, gas_O2sat, gas_schmidt, gas_solubility, gas_transfer, atmComp, vapor, air_spechum, air_density


convert_AStoPS, convert_PStoAS, convert_RtoS, convert_StoCl, convert_StoR, convert_p, convert_T


AtomicWeight, Bathymetry, Constants, Oceans

physical properties:

earth_surf, coriolis, viscosity, diffcoeff, ssd2rad, vertmean, gravity

molecular properties:

AtomicWeight, molvol, molweight, redfield


## Not run: 
## show examples (see respective help pages for details)

## open the directory with documents
browseURL(paste(system.file(package="marelac"), "/doc", sep=""))

## End(Not run)

marelac documentation built on Sept. 25, 2023, 5:06 p.m.