@article{fdi:010085012,
  title = {{G}eneration mechanism of spiciness anomalies : an {OGCM} analysis in the {N}orth {A}tlantic subtropical gyre},
  author = {{L}aurian, {A}. and {L}azar, {A}lban and {R}everdin, {G}.},
  editor = {},
  language = {{ENG}},
  abstract = {{O}ceanic teleconnections between the low and midlatitudes are a key mechanism to understanding the climate variability. {S}piciness anomalies (density-compensated anomalies) have been shown to transport temperature and salinity signals when propagating along current streamlines in the subtropical gyres of the {A}tlantic and {P}acific {O}ceans. {T}he generation mechanism of spiciness anomalies in the {N}orth {A}tlantic subtropical gyre is investigated using an analytical model based on the late-winter subduction of salinity and temperature anomalies along isopycnal surfaces. {T}he keystone of this approach is the change of the coordinates frame from isobaric to isopycnic surfaces, suited for subduction problems. {T}he isopycnal nature of spiciness anomalies and the use of a linear density equation allows for the analytical model to depend only upon surface temperature and salinity anomalies, the mean thermocline currents, and the surface density ratio. {T}his model clarifies and above all quantifies the mechanism by which surface temperature and salinity anomalies are modulated by density ratios to produce fully different isopycnal temperature and salinity anomalies. {A} global run from the ocean {GCM} ({OGCM}) {O}cean {P}arallelise ({OPA}) over the period 1948-2002 provides the reference data in which the {N}orth {A}tlantic subtropical thermocline spiciness variability is analyzed. {T}wo {EOF} modes are sufficient to explain half of the low-frequency variability in the {OGCM}: one is maximum over the northeastern subtropics, and the other is in the central basin. {T}he analytical model reproduces well the spatial pattern, amplitude, and sign of these two main modes. {I}t confirms that the two centers of action of the anomalies are conditioned by the surface density ratio, the first corresponding to null salinity gradients and the second to near-density-compensated temperature gradients. {C}onsidering that the analytical model has good skills at reproducing the decadal variability of the {OGCM} spiciness anomalies in the permanent thermocline, it is believed that this is an interesting tool to understand and forecast the ventilation of the {N}orth {A}tlantic subtropical gyre at this time scale.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {P}hysical {O}ceanography},
  volume = {39},
  numero = {4},
  pages = {1003--1018},
  ISSN = {0022-3670},
  year = {2009},
  DOI = {10.1175/2008jpo3896.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010085012},
}