Temporal variability of the anthropogenic CO₂ storage in the Irminger Sea

F. F. Pérez (1) , M. Vázquez-Rodríguez (1) , E. Louarn (2) , X. A. Padín (1) , H. Mercier (3) , A. F. Ríos (1)

1 Instituto de Investigaciones Marinas
2 AD2M - Adaptation et diversité en milieu marin
3 LPO - Laboratoire de physique des océans

The anthropogenic CO₂ (C_ant) estimates from cruises spanning more than two decades (1981–2006) in the Irminger Sea area reveal a large variability of the C_ant storage rates in the North Atlantic Subpolar Gyre. During the early 1990's, the C_ant uptake rates doubled the average rate for 1981–2006, whilst a remarkable drop to almost half that average followed from 1997 onwards. The C_ant storage evolution runs parallel to CFC12 inventories and is in good agreement with C_ant uptake rates of increase calculated from sea surface pCO₂ measurements. The North Atlantic Oscillation shift from a positive to a negative phase in 1996 led to a reduction of the air-sea heat loss in the Labrador Sea. The consequent convection weakening accompanied by an increase in stratification lowered the efficiency of the northern North Atlantic CO₂ sink.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

F. F. Pérez, M. Vázquez-Rodríguez, E. Louarn, X. A. Padín, H. Mercier, et al.. Temporal variability of the anthropogenic CO₂ storage in the Irminger Sea. Biogeosciences Discussions, 2008, 5 (2), pp.1587-1606. ⟨hal-00330294⟩