Temporal variability of the anthropogenic CO 2 storage in the Irminger Sea

• Main Authors: H. Mercier, X. A. Padín, E. Louarn, M. Vázquez-Rodríguez, F. F. Pérez, A. F. Ríos
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2008
• Subjects: Ecology; QH540-549.5; Life; QH501-531; Geology; QE1-996.5; Irminger Sea; Irminger Basin; Labrador Sea; North Atlantic; North Atlantic oscillation
• Online Access: https://doaj.org/article/711f5a87814841cd8c2e4c505bbae567

The anthropogenic CO 2 (C ant ) estimates from cruises spanning more than two decades (1981–2006) in the Irminger Sea area of the North Atlantic Subpolar Gyre reveal a large variability in the C ant storage rates. During the early 1990's, the C ant storage rates (2.3±0.6 mol C m −2 yr −1 ) doubled the average rate for 1981–2006 (1.1±0.1 mol C m −2 yr −1 ), whilst a remarkable drop to almost half that average followed from 1997 onwards. The C ant storage evolution runs parallel to chlorofluorocarbon-12 inventories and is in good agreement with C ant uptake rates of increase calculated from sea surface p CO 2 measurements. The contribution of the Labrador Seawater to the total inventory of C ant in the Irminger basin dropped from 66% in the early 1990s to 49% in the early 2000s. The North Atlantic Oscillation shift from a positive to a negative phase in 1996 led to a reduction of air-sea heat loss in the Labrador Sea. The consequent convection weakening accompanied by an increase in stratification has lowered the efficiency of the northern North Atlantic CO 2 sink.