Transports and budgets of anthropogenic CO2 in the tropical North Atlantic in 1992–1993 and 2010–2011

• Published in: Global Biogeochemical Cycles
• Main Authors: Zunino, P., Pérez, Fiz F., Fajar, Noelia, Fernández-Guallart, E., Ríos, Aida F., Pelegrí, Josep Lluís, Hernández Guerra, Alonso
• Other Authors: Ministerio de Economía y Competitividad (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2015
• Subjects: Las Palmas; North Atlantic Deep Water; North Atlantic
• Online Access: http://hdl.handle.net/10261/121690; https://doi.org/10.1002/2014GB005075; https://doi.org/10.13039/501100003329

17 páginas, 8 figuras, 5 tablas The meridional transport of anthropogenic CO2 (Cant) in the tropical North Atlantic (TNA) is investigated using data from transoceanic sections along 7.5°N and 24.5°N, carried out in the early 1990s and 2010s. The net Cant transport across both sections is northward. At 7.5°N, this transport increased from 315 ± 47 kmol s−1 in 1993 to 493 ± 51 kmol s−1 in 2010; similarly, across 24.5°N it grew from 530 ± 46 kmol s−1 in 1992 to 662 ± 49 kmol s−1 in 2011. These changes result from modifications in the intermediate and deep circulation patterns, as well as from Cant increase within the thermocline waters. In deep waters, lateral advection causes a net Cant input of 112 ± 60 kmol s−1 (234 ± 65 kmol s−1) in 1992–1993 (2010–2011); within these deep waters, the storage rate of Cant is not statistically different from the net Cant input, 139 ± 21 kmol s−1 (188 ± 21 kmol s−1) in 1992–1993 (2010–2011). The Cant increase in deep waters is due to the large injection of Cant across the 24.5°N by the Deep Western Boundary Current and the northward recirculation of North Atlantic Deep Water along 7.5°N. In contrast, a large net Cant output in the upper layer is caused by the Florida Current. Despite this net Cant output, the Cant accumulates at a rate of 215 ± 24 kmol s−1 (291 ± 24 kmol s−1) referenced to year 1993 (2010). From the two Cant budgets, we infer a Cant air-sea flux of 0.23 ± 0.02 Pg yr−1in the TNA, much larger than previous estimates The first author received a grant from the Tricontinental Atlantic Campus spending a 6 month period at the Universidad de Las Palmas de Gran Canaria where this study was carried out. This work has been performed under the projects MOC2 (CTM2008- 06438), Malaspina (CSD2008-00077), BOCATS (CTM2013-41048-P), and TIC-MOC (CTM2011-28867) supported by the Spanish Government and cofounded by the European Regional Development Fund (FEDER) Peer reviewed