Wind-driven circulation for the eastern North Atlantic Subtropical Gyre from Argo data

ÈN]A trans-oceanic section at 24.5°N in the North Atlantic has been sampled at a decadal frequency. This work demonstrates that the wind-driven component of the Meridional Overturning Circulation (MOC) may be monitored using autonomous profiling floats deployed in the eastern North Atlantic Subtropical Gyre. More than 500 CTD vertical profiles from the surface to 2000 m depth, spanning one year (from April 2002 to March 2003), are used to compute the geostrophic transport stream function at 24.5°N. The baroclinic transport obtained from the autonomous profiling floats is not statistically different than that from three hydrographic cruises carried out in 1957, 1981 and 1992. A good agreement is found between the geostrophic transport stream function and the transport derived from the wind field through the Sverdrup relation.

Multiproperty modeling for a set of binary systems. Evaluation of a model to correlate simultaneously several mixing properties of methyl ethanoate+alkanes and new experimental data

[EN] This work makes a theoretical–experimental contribution to the study of ester and alkane solutions. Experimental data of isobaric vapor–liquid equilibria (VLE) are presented at 101.3 kPa for binary systems of methyl ethanoate with six alkanes (from C5 to C10), and of volumes and mixing enthalpies, vE and hE.

Solutions of alkyl methanoates and alkanes: Simultaneous modeling of phase equilibria and mixing properties. Estimation of behavior by UNIFAC with recalculation of parameters.

[EN]Isobaric vapor–liquid equilibria at p = 101.32 kPa (iso-p VLE) and the mixing properties, hE and vE, are determined for a set of twelve binary solutions: HCOOCuH2u+1(1)+CnH2n+2(2) with u = (1–4) and n = (7– 9). The (iso-p VLE) present deviations from the ideal behavior, which augment as u diminishes and n increases. Systems with [u = 2,3 n = 7] and [u =4 , n = 7,8] present a minimum-boiling azeotrope. The nonideality is also reflected in high endothermic values, hE > 0, and expansive effects, vE > 0, for all the binaries, which increase regularly with n