Recent changes in subsurface temperature and salinity in the Canary region

Abstract

Based on hydrographic sections carried out during the last decade in the Canary region at 29º10'N, we show that there has been a statistically significant rise in temperature and salinity on isobars between 1500 and 2300 db. The maximum increase, found at 1600 db, is occurring at a rate of0.29ºC and 0.047 per decade. lsobaric change decomposition into changes on neutral surfaces and changes due to the vertical displacement of the isoneutrals was performed. Results revea] that the lower part ofNorth Atlantic Central Water (NACW) cooled and freshened on neutral surfaces, suggesting changes in the freshwater fluxes at the outcropping region. However, the signa] in deep waters (1500-2300 db) was principally due to a downward displacement ofthe isoneutrals, although water mass modification is observed in the range of Mediterranean Water (MW) influence.