version 2.1.0, 2009-04-21

- the pHscales were added in option to calculate the constants of acidity and in the functions : carb, buffer, pgas, pTA, pCa, ppH, pmix and psi.
- the choice of the method of calculation for K1, K2 and Kf was added in option in the functions : carb, buffer, pgas, pTA, pCa, ppH, pmix and psi.
- two bugs were fixed in the function carb: one about effect of pressure (P) and the other one in the computation of pCO2 and fCO2 when (P>0).
- pHconv was changed in order to fix a bug and facilitate his using.

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version 2.0.9, 2009-04-20
- added function psi

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version 2.0.8, 2009-04-16
- changed the help file of seacarb_test to remove the use of \item (it prevented compilation on CRAN).

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version 2.0.7, 2009-04-07
- changed the help file of ppH to correct an error concerning the addition of acid (the normality was wrong).

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version 2.0.6, 2009-02-09
Changes made thanks to comments kindly provided by Andreas Hofmann (A.Hofmann@nioo.knaw.nl):
- Kf was modified in order to convert Kf from free scale to total scale after pressure corrections in the Dickson and Goyet Method.

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version 2.0.5, 2008-12-08

Changes made thanks to comments kindly provided by Andreas Hofmann (A.Hofmann@nioo.knaw.nl):
- K2 modified to fix a bug which provided warnings when several pressures were used.
- Khs modified to fix a bug (in coefficient a2).
- The value of the R constant was updated according to Dickson et al. (2007). The new value is 8.314475 J/(K*mol).
- kconv was modified in order to include pressure correction.

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version 2.0.4, 2008-11-06

- pH, pTA, pmix, pCa, and pgas now accept Sit (concentration of silicate) and Pt (concentration of total phosphate) as input arguments.
- Various style changes in the help files.

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version 2.0.3, 2008-11-04

- The code of all functions which calculate constants was modified in order to be able to use vectors as input arguments.
- The man files were changed accordingly by adding a "details" section.

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version 2.0.1, 2008-10-28

- added the data set seacarb_test
- added and example to use carb with a data frame
- various cosmetic changes in the help files

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version 2.0, 2008-10-27

- added function "pCa" which calculates the changes in the saturation states of aragonite and calcite resulting from the manipulation of the calcium concentration
- added function "pgas" which calculates the carbonate chemistry after changes in pCO2 generated by gas bubbling
- added function "pmix" which calculates the carbonate chemistry after mixing of two water samples with different pCO2
- added function "ppH" which calculates the carbonate chemistry after pH manipulations through addition of acid or base
- added function "pTA" which calculates the carbonate chemistry following addition of CO3 or HCO3
- carb function modified to return only S, T, P, pH, pCO2, fCO2, HCO3, CO3, DIC, ALK, OmegaAragonite and OmegaCalcite.
- added function "buffer" which calculates the buffer parameters of the seawater carbonate system. 
- carb function modified in order to closely follow the recommendations of the "Guide to Best Practices for Ocean CO2 Measurements" (Dickson et al., 2007). Phosphate ans ilicate concentrations are now taken into account.
- K1 function uses the equation of Lueker et al. (2000) by default
- K2 function uses the equation the method of Lueker et al. (2000) by default
- Kf function uses, by default, the equation of Perez and Fraga (1987). The equation of Dickson and Roy can be used with the argument kf = 'dg'.

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version 1.2.3, 2007-11-27

- carb function modified to allow NA values in the input data. A warning is returned if this happens but all other data rows are processed. Change made by Bernard Gentili.

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version 1.2.2, 2007-09-09

- correction of the definition of PiH and PhiH in the "carb" documentation file
- BetaD is the Revelle factor (the "carb" documentation has been updated
- cosmetic changes to some documentation files

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version 1.2.1, 2007-08-21

- cosmetic changes to some documentation files

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version 1.2, 2007-08-21

- added function "speciation" which estimates the concentration of the various ionic forms of a molecule as a function of pH (contributed by Karline Soetaert)
- added function "kconv" which provides conversion factors to change the pH scale of dissociation constants (contributed by Karline Soetaert)
- added function "pHconv" which provides conversion factors for changing the pH scale (contributed by Karline Soetaert)
- added function "Kn" which provides the ammonium dissociation constant (contributed by Karline Soetaert)
- added function "Khs" which provides the dissociation constant of hydrogen sulfide (contributed by Karline Soetaert)
- added function "Ksi" which provides the Si(OH)4 dissociation constant (contributed by Karline Soetaert)
- added function "bjerrum" which makes a bjerrum plot (contributed by Karline Soetaert)

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version 1.1.1, 2007-08-14

- bor(), K1(), K1p() and K2() now return the values
- return values are now set for all variables
 
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version 1.1, 2007-07-24

- carb() has now 5 more flags (code contributed by Jim Orr):
	# flag = 21     pH-pCO2 given
	# flag = 22     pCO2-HCO3 given
	# flag = 23     pCO2-CO3 given
	# flag = 24     pCO2-ALK given
	# flag = 25     pCO2-DIC given 

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version 1.0.5, 2007-07-23

- minor changes to the documentation (tried to have the superscripts right)

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version 1.0, 2007-01-08

- added function phinsi which calculates the pH at in situ temperature from pH values measured in the laboratory and other ancillay data

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version 1.0, 2007-01-08

- a test data file is now provided
- various cosmetic changes

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version 0.98, 2006-05-07

- data entry via a file is NO LONGER possible
- results of the carb command are no longer automatically saved in a file
