In this modeling study we investigate the dynamical mechanisms controlling the spreading of the Magellan Plume, which is a low-salinity tongue that extends along the Patagonian Shelf. Our results indicate that the overall characteristics of the plume (width, depth, spreading rate, etc.) are primarily influenced by tidal forcing, which manifests...
This study shows that simulations of bottom-trapped plumes in periodic or closed domains generate a spurious cyclonic current that arrests the natural tendency of the plume to move upstream. Furthermore, it also shows that attempts to obstruct the upstream spreading lead to a bias of the fundamental characteristics of the...
This note considers the decay of a bottom-trapped freshwater plume after the causative freshwater inflow
has ceased. It is shown that shortly after the low-density inflow stops, the barotropic pressure field that it
created radiates away and the ocean circulation becomes controlled by baroclinic pressure gradients generated
by the remnants...
It is well known that numerical simulations of freshwater discharges produce plumes that spread in the
direction opposite to that of the propagation of coastally trapped waves (the upstream direction). The lack of
a theory explaining these motions in unforced environments deemed the numerical results suspect. Thus, it
became a...
The term “downwelling currents” refers to currents with a downslope mass flux in the bottom boundary layer. Examples are the Malvinas and Southland Currents in the Southern Hemisphere and the Oyashio in the Northern Hemisphere. Although many of these currents generate the same type of highly productive ecosystems that is...
The objective of this study is to evaluate the performance of several
open boundary conditions applied to the Princeton ocean model. The focus is on
passive open boundary conditions applied to the external mode, i.e., conditions that
are applied when the mean flow at the open boundary is unknown and...
Tl1is article discusses the results of an experimental survey on the
performance of a select group of open boundary conditions (OBCs) for three-dimensional,
primitive equation models. The focus is on passive conditions, where
the model response at the open boundaries is dictated by the interior dynamics. The
performance of the...
Alongshore flow in the direction of propagation of coastal trapped waves can result in upwelling at the shelfbreak. The intensity of this upwelling can be comparable in magnitude to wind-driven coastal upwelling, with its associated ecological features. Recent numerical experiments by Matano & Palma indicate that this upwelling results from...
Alongshore flow in the direction of propagation of coastal trapped waves can result in upwelling at the shelfbreak. The intensity of this upwelling can be comparable in magnitude to wind-driven coastal upwelling, with its associated ecological features. Recent numerical experiments by Matano & Palma indicate that this upwelling results from...
We compare the oceanic circulation patterns over the
Southwestern Atlantic Shelf (SWAS) forced by nine
different wind stress climatologies. The largest differences
are observed in experiments forced with the Hellerman
and Rosenstein [1983, hereafter HR83] and Trenberth
et al. [1990, hereafter TR90] winds. HR83 shows a
general northeastward flow near...
This article discusses the results of a suite of numerical simulations of the oceanic
circulation in the Southwestern Atlantic Shelf region that are aimed to characterize its
mean circulation and seasonal variability and to determine the dynamical mechanisms
controlling them. Our experiments indicate that south of 40°S the mean circulation...
This article analyzes the barotropic circulation in the Southwestern Atlantic Shelf using
a three-dimensional numerical model forced with winds and tides. South of 40°S, the shelf
circulation is dominated by the propagation of the semidiurnal tides. In this region the
diurnal tides are generally weak, except at the shelf edge...
The influence of the Plata, the second largest river in
South America, extends along a coastal strip of 1300 km.
Historical hydrographic and wind data and numerical
simulations are combined to determine the seasonal and
interannual variability of the Plata plume and its relationship
to the magnitude of the river...
Satellite-derived sea surface salinity (SSS) data from Aquarius and SMOS are used to study the
shelf-open ocean exchanges in the western South Atlantic near 35°S. Away from the tropics, these
exchanges cause the largest SSS variability throughout the South Atlantic. The data reveal a well-defined
seasonal pattern of SSS during...
Full Text:
. R., Fenco, H., Matano, R. P., Combes, V., Chao, Y.,
James, C., Palma, E. D., Saraceno, M., & Ted
Satellite-derived sea surface salinity (SSS) data from Aquarius and SMOS are used to study the
shelf-open ocean exchanges in the western South Atlantic near 35°S. Away from the tropics, these
exchanges cause the largest SSS variability throughout the South Atlantic. The data reveal a well-defined
seasonal pattern of SSS during...
Full Text:
on 27 May 2010 (a) and 25 January
2011 (b), SSS distributions from Aquarius (c) and SMOS (d) for 12
Altimeter sea surface height (SSH) fields are analyzed to define and discuss the seasonal circulation over the wide continental shelf in the SW Atlantic Ocean (27°–43°S) during 2001–2012. Seasonal variability is low south of the Rio de la Plata (RdlP), where winds and currents remain equatorward for most of the...
Satellite‐derived sea surface salinity (SSS) data from Aquarius and SMOS are used to study the shelf‐open ocean exchanges in the western South Atlantic near 35°S. Away from the tropics, these exchanges cause the largest SSS variability throughout the South Atlantic. The data reveal a well‐defined seasonal pattern of SSS during...
This article presents a semianalytic method to investigate the properties of energy transmission across bottom topography by barotropic Rossby waves. The method is first used to revisit the analytical estimates derived from wave-matching techniques and Wentzel–Kramers–Brillouin (WKB) approximations. The comparison between the semianalytic method and WKB indicates that the results...
A new enhanced swing class-D VCO which operates from a supply voltage as low as 300 mV is presented. The architectural advantages are described along with an analysis for the oscillation frequency. Prototype differential and quadrature variants of the proposed VCO have been implemented in a 65 nm RF CMOS...