Reconstruction of the Gulf Stream since 1900 and correlation with the North Atlantic Oscillation

• Main Authors: Watelet, Sylvain, Beckers, Jean-Marie, Barth, Alexander, Ouberdous, Mohamed, Troupin, Charles
• Format: Conference Object
• Language: English
• Published: European Geosciences Union 2014
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://hdl.handle.net/10261/123198

Trabajo presentado en la EGU General Assemby 2014, celebrada del 27 de abril al 2 de mayo de 2014 en Viena (Austria) Prevailing winds over the North Atlantic (NA) have a direct influence on the location and intensity of the Gulf Stream (GS) by the transfer of momentum between atmosphere and ocean. Therefore, the study of interannual variability of the GS requires the identification of sources of variability within the atmospheric circulation. Various studies have highlighted the impact of the North Atlantic Oscillation (NAO) on the variability of the GS transport. However, there is still no scientific consensus thereupon. On the one hand, several scientific papers (Sato & Rossby, 1995; Curry & McCartney, 2001; deCoëtlogon et al., 2006) exhibit a decrease of the GS transport during low NAO periods, as well as a higher transport during high NAO phases. On the second hand, studies of Gangopadhyay et al. (1992), Baringer & Larsen (2001) and DiNezio et al. (2009) suggest a lower transport during positive phases of the NAO. Finally, Chaudhuri et al. (2011) obtained a more complex conclusion, whereby the influence of the NAO is different upstream and downstream of Cape Hatteras. This currently limited understanding of the links between the NAO and the GS in NA, impels us to further analyze the spatial and temporal distribution of the GS. Our main purpose in this study is to reconstruct a spatially continuous field of ocean (sub)surface circulation in the NA from in situ time series of discrete steps, in order to accurately quantify the position and intensity of the GS since 1900. From there, we will be able to examine the correlation of this current with the NAO. To this end, we used the DIVA (Data-Interpolating Variational Analysis) tool, which is a numerical implementation of the variational inverse method (VIM) using the finite elements method to reconstruct continuous fields from discrete measurements. These measurements of temperature, salinity and currents since the beginning of the last century ...