Abstract:
To study the anthropogenic carbon penetration in the Mediterranean Sea and in the Algerian
basin particularly, we have calculated it by using the TrOCA method (Touratier et al., 2007),
the ∆C* method (Gruber et al. 1996) and a method derived from that of Chen and Millero,
1979 using the METEOR 51/2 data with an adaptation to the Mediterranean particularities.
From the obtained results, we have established multi-parameter equation linking dissolved
inorganic carbon to temperature, salinity and oxygen, which allow us to calculate the
anthropogenic carbon in the Algerian basin and see its evolution from 1957 to 1999 based on
the MEDAR/MEDATLAS data.
After validation on DYFAMED data, we can conclude that the TrOCA method
overestimates the anthropogenic carbon penetration, and the well adapted method to the
Mediterranean Sea seems to be that derived from of Chen and Millero, 1979. The results for
the Algerian basin show that the anthropogenic carbon penetration is increasingly deeper with
time in the water column and that it is play rather a source role. The surface pH decrease
progressively controlled by the surface pCO 2 . This diminution causes a weak diminution in
aragonite and calcite saturation state but it remains about 3.5 and 5 times oversaturated
respectively. The previsions for the year 2100 for 563 and 788 ppm in pCO 2 show that the
Algerian basin would still be oversaturated in calcium carbonate.
Keywords : Algérian basin, anthropigenic carbon, pCO 2 , pH, Calcite, Aragonite