INVESTIGADORES
NUÑEZ Mario Nestor
artículos
Título:
Barotropic tide and baroclinic waves observations in the Río de la Plata Estuary
Autor/es:
SIMIONATO, C; MECCIA, V; DRAGANI, W; NUÑEZ, M. N.
Revista:
JOURNAL OF GEOPHYSICAL RESEARCH
Editorial:
American Geophysical Union
Referencias:
Lugar: Washington, D.C.; Año: 2005 vol. 110 p. 1 - 16
ISSN:
0148-0227
Resumen:
[1] The first long-period ADCP series collected in two locations of the salinity front of
the Rý´o de la Plata estuary are explored for periods less than 30 hours. Barotropic velocity
shows tidal and mean currents consistent with what is known about the estuarine
circulation in tidal and seasonal scales. Baroclinic currents provide the first evidence of the
occurrence of internal waves, which can account for half of the total variance. In the
northernmost location, predominantly zonal oscillations with semidiurnal period, and
oscillations with a dominant meridional component and diurnal period, are found.
Whereas the first ones can be related to the semidiurnal tide, the second ones seem to be
atmospherically forced by the land/sea breeze. In the southernmost location, more
rotational oscillations are observed, with periods around the inertial and diurnal ones.
Inertial oscillations could result from wind relaxation, whereas diurnal oscillations also
seem to be forced by breeze. Wave activity in the diurnal band was less frequent in the
northernmost than in the southernmost location. This can be attributed to less frequent
favorable stratification conditions in that area during the observed period. Wave activity in
the southernmost location resulted weaker during the observed fall than during the
summer. This could be a typical feature given that in autumn both the number of storms
destroying the thermohaline structure increases and land/sea breeze is less frequent. This
suggests a likely seasonal cycle in the diurnal wave activity in this area, given that those
unfavorable conditions are even more marked during winter.
the Rý´o de la Plata estuary are explored for periods less than 30 hours. Barotropic velocity
shows tidal and mean currents consistent with what is known about the estuarine
circulation in tidal and seasonal scales. Baroclinic currents provide the first evidence of the
occurrence of internal waves, which can account for half of the total variance. In the
northernmost location, predominantly zonal oscillations with semidiurnal period, and
oscillations with a dominant meridional component and diurnal period, are found.
Whereas the first ones can be related to the semidiurnal tide, the second ones seem to be
atmospherically forced by the land/sea breeze. In the southernmost location, more
rotational oscillations are observed, with periods around the inertial and diurnal ones.
Inertial oscillations could result from wind relaxation, whereas diurnal oscillations also
seem to be forced by breeze. Wave activity in the diurnal band was less frequent in the
northernmost than in the southernmost location. This can be attributed to less frequent
favorable stratification conditions in that area during the observed period. Wave activity in
the southernmost location resulted weaker during the observed fall than during the
summer. This could be a typical feature given that in autumn both the number of storms
destroying the thermohaline structure increases and land/sea breeze is less frequent. This
suggests a likely seasonal cycle in the diurnal wave activity in this area, given that those
unfavorable conditions are even more marked during winter.
1] The first long-period ADCP series collected in two locations of the salinity front of
the Rý´o de la Plata estuary are explored for periods less than 30 hours. Barotropic velocity
shows tidal and mean currents consistent with what is known about the estuarine
circulation in tidal and seasonal scales. Baroclinic currents provide the first evidence of the
occurrence of internal waves, which can account for half of the total variance. In the
northernmost location, predominantly zonal oscillations with semidiurnal period, and
oscillations with a dominant meridional component and diurnal period, are found.
Whereas the first ones can be related to the semidiurnal tide, the second ones seem to be
atmospherically forced by the land/sea breeze. In the southernmost location, more
rotational oscillations are observed, with periods around the inertial and diurnal ones.
Inertial oscillations could result from wind relaxation, whereas diurnal oscillations also
seem to be forced by breeze. Wave activity in the diurnal band was less frequent in the
northernmost than in the southernmost location. This can be attributed to less frequent
favorable stratification conditions in that area during the observed period. Wave activity in
the southernmost location resulted weaker during the observed fall than during the
summer. This could be a typical feature given that in autumn both the number of storms
destroying the thermohaline structure increases and land/sea breeze is less frequent. This
suggests a likely seasonal cycle in the diurnal wave activity in this area, given that those
unfavorable conditions are even more marked during winter.