Activities
Daily re-analysis of temperatures and salinity records, from MERCATOR GLORYS2V3, are used to analyze the variabilities of Density Mixed Layer Depth (MLD), Isothermal Layer Depth (ILD) and Barrier Layer Thickness (BLT) at PIRATA buoys locations in tropical Atlantic Ocean from 2000 to 2008. Seasonal cycles have gone from 1993 to 2013 to validate data results with previous studies. The presence of significant barrier layer is noticed at 8 positions, where correlations between the Isotherm Layer Depth and density Mixed Layer Depth are significants, but with coefficients less than 0.90, except at 0°N-35°W. At 19°S-34°W, we noticed a strong vertically Compensated Layer (CL), especially in summer-autumn in the northern hemisphere. Study of intra-seasonal variability shows the influence of Tropical Instabilities Waves (TIWs) on Isotherm Layer Depth variability at 4°N-38°W. Correlations between density Mixed Layer Depth and Isotherm Layer Depth show that seasonal variability of Barrier layer (BL) is linked with Isotherm Layer Depth at 20°N-38°W, 15°N-38°W and 4°N-38°W. At 8°N-38°W, the influence of North Equatorial Counter Current (NECC) which transports Amazon fresh water, on Sea Surface Salinity (SSS) is the main mechanism that explains seasonal variability of Barrier Layer (BL). Inter-annual variability of the Isotherm Layer at positions 12°N-38°W, 4°N-38°W, 4°N-23°W and 0°N-35°W is associated to sea level variability, and especially the intensification of westward wind at 0°N-35°W.
Skills
Training on mixe and barrier layers variabilities in tropical Atlantic