13C Suess Effect in the Gulf of Mexico Deep Waters

The increase of atmospheric CO₂ concentrations product of anthropogenic activities has been traced by a depletion in its ¹³C to ¹²C ratio in what is called the ¹³C Suess Effect. As the ocean dissolves the atmospheric CO₂, the Suess effect signal gets printed in the dissolved inorganic carbon isotopic composition (δ¹³C _CID) and can be used as a tracer for the anthropogenic carbon sink in the ocean.

We show the spatial and temporal variation of δ¹³C _CID data from 2010 to 2018 in the Gulf of Mexico deep waters and estimate the Suess Effect in the water masses present in this basin. The δ¹³C _CID values show a Suess Effect as a decreasing tendency of -0.008‰ per year, with the shallower water masses showing the higher anual depletions.