Ship and Satellite Studies of Mesoscale Circulation and Sperm Whale Habitats in the Northeast Gulf of Mexico During GulfCet II

Eighty-three encounters with sperm whales (Physeter macrocephalus) occurred on two cruises that made expendable bathythermograph + conductivity-temperature-depth surveys of cyclone-anticyclone eddy pairs in the Northeast Gulf of Mexico (NEGOM). In late summer 1996, 41 sightings of sperm whales were made and 10 acoustic contacts were registered. Of these 51 encounters, 90% were in a cyclonic area of lower than average dynamic height offshore that was surveyed from space by near-real-time altimetric sea surface height anomaly and then mapped in high resolution with shipboard measurements or within 100 km of SW Pass of the Mississippi River. In midsummer 1997, 23 sightings and nine acoustic contacts were made. Of these 32 encounters, 81% were in an offshore cyclonic area of lower than average dynamic height or within 100 km of the mouth of the Mississippi River. Time series animation of the 1996 and 1997 altimetric data indicated these cyclones are typically associated with Loop Current excursions into the NEGOM and that the two cyclones we surveyed had spun up 4-6 mo previous to our fieldwork. Although cyclones in the NEGOM are temporally persistent, their geographic location is spatially variable: the cyclone surveyed in 1996 was centered 150-200 km south and east of the Mississippi River delta in water 2-3 km deep, whereas that surveyed in 1997 was centered farther east in water 2-3 km deep over DeSoto Canyon. Sperm whales appear to have affinity for cyclonic eddies because the largest numbers of encounters with sperm whales also shifted east in 1997 compared with 1996

The Meanings of Consonants

Proceedings of the Twenty-Ninth Annual Meeting of the Berkeley Linguistics Society: General Session and Parasession on Phonetic Sources of Phonological Patterns: Synchronic and Diachronic Explanations (2003

Variability of satellite-derived sea surface height anomaly, and its relationship with Bigeye tuna (Thunnus obesus) catch in the Eastern Indian Ocean

We analyzed the variability of sea surface height anomaly (SSHA), and its relationship with Bigeye tuna catch in the eastern Indian Ocean (EIO) off of Java Island (Indonesia). Both time series of SSHA and Bigeye tuna HR show dominant signals corresponding to the annual and inter-annual variability. During the southeast monsoon the wind blows along southern coast of Java and produces coastal upwelling. This causes sea level to drop due to an offshore Ekman transport, and thermocline becomes shallower. During El Niño and Indian Ocean Dipole (IOD) positive phase, upwelling is more intense and a large cold eddy forms in the EIO off Java. Generally, Bigeye tuna HR tends to increase during upwelling seasons and becomes even higher during El Niño and the positive phase of the IOD. The increased Bigeye tuna HR during the southeast monsoon, El Niño and the IOD positive phase can be attributed to the shallower thermocline depth and the enhancement of biological productivity due to development of eddies and strong upwelling in the EIO. The spatial distribution of SSHA indicates that Bigeye tuna catches are abundant in the frontal regions between cold and warm eddies

Eddies de mesoescala en el frente Subantártico, Atlántico sudoeste

Satellite and ship observations in the southern southwest Atlantic (SSWA) reveal an intense eddy field and highlight the potential for using continuous real-time satellite altimetry to detect and monitor mesoscale phenomena with a view to understanding the regional circulation. The examples presented suggest that mesoscale eddies are a dominant feature of the circulation and play a fundamental role in the transport of properties along and across the Antarctic Circumpolar Current (ACC). The main ocean current in the SSWA, the Falkland-Malvinas Current (FMC), exhibits numerous embedded eddies south of 50°S which may contribute to the patchiness, transport and mixing of passive scalars by this strong, turbulent current. Large eddies associated with meanders are observed in the ACC fronts, some of them remaining stationary for long periods. Two particular cases are examined using a satellite altimeter in combination with in situ observations, suggesting that cross-frontal eddy transport and strong meandering occur where the ACC flow intensifies along the sub-Antarctic Front (SAF) and the Southern ACC Front (SACCF).Observaciones in situ y satélites en el sudoeste del Océano Atlántico Sur revelan un intenso campo de eddies e indican la utilidad de la altimetría satelital para detectar, monitorizar y mejorar la comprensión de fenómenos de mesoescala en la región. Los ejemplos presentados sugieren que los eddies de mesoescala son una característica dominante de la circulación y juegan un papel fundamental en el transporte de propiedades a lo largo y a través de la Corriente Circumpolar Antártica (CCA). Al sur de 50°S la principal corriente en esta región, la Corriente de Malvinas exhibe numerosos eddies, los que pueden contribuir al patrón de manchas, y al transporte y la mezcla de trazadores pasivos de esta intensa y turbulenta corriente. En los frentes de la CCA se observan grandes eddies asociados con meandros, algunos de estos eddies permanecen estacionarios durante largos períodos de tiempo. Se analizan dos casos particulares empleando altimetría satelital en combinación con observaciones in situ que sugieren que donde la CCA se intensifica, a lo largo del Frente Subantártico y el Frente Sur de la CCA, se producen intensos transportes a través de la corriente y fuertes meandramientos

Ship and Satellite Studies of Mesoscale Circulation and Sperm Whale Habitats in the Northeast Gulf of Mexico During GulfCet II

Eighty-three encounters with sperm whales (Physeter macrocephalus) occurred on two cruises that made expendable bathythermograph + conductivity-temperature-depth surveys of cyclone-anticyclone eddy pairs in the Northeast Gulf of Mexico (NEGOM). In late summer 1996, 41 sightings of sperm whales were made and 10 acoustic contacts were registered. Of these 51 encounters, 90% were in a cyclonic area of lower than average dynamic height offshore that was surveyed from space by near-real-time altimetric sea surface height anomaly and then mapped in high resolution with shipboard measurements or within 100 km of SW Pass of the Mississippi River. In midsummer 1997, 23 sightings and nine acoustic contacts were made. Of these 32 encounters, 81% were in an offshore cyclonic area of lower than average dynamic height or within 100 km of the mouth of the Mississippi River. Time series animation of the 1996 and 1997 altimetric data indicated these cyclones are typically associated with Loop Current excursions into the NEGOM and that the two cyclones we surveyed had spun up 4-6 mo previous to our fieldwork. Although cyclones in the NEGOM are temporally persistent, their geographic location is spatially variable: the cyclone surveyed in 1996 was centered 150-200 km south and east of the Mississippi River delta in water 2-3 km deep, whereas that surveyed in 1997 was centered farther east in water 2-3 km deep over DeSoto Canyon. Sperm whales appear to have affinity for cyclonic eddies because the largest numbers of encounters with sperm whales also shifted east in 1997 compared with 1996

Shelf break Exchange Events near the De Soto Canyon

Observations of currents, temperature, sea-surface height, sea-surface temperature and ocean color, derived from moorings, surface and deep drifters, hydrographic surveys, and satellites, are used to characterize shelf-slope exchange events near the apex of the De Soto Canyon in the northeast Gulf of Mexico. During the winter of 2012–2013, shelf-break time series showed a number of events where cold shelf water extruded over the slope. These events were largely consistent with slope eddies of both signs influencing shelf break currents. Larger-scale circulations, derived from the Loop Current and a separating Loop Current eddy, strongly influenced circulation over the De Soto slope during summer 2012, with flow patterns consistent with potential vorticity conservation over shoaling topography. Statistical investigation into shelf-slope exchange using large numbers of surface drifters indicated that export from the shelf is larger than vice-versa, and is more uniformly distributed along the shelf break. Import onto the shelf appears to favor a region just east of the Mississippi Delta, which is also consistent with the observed onshore transport of surface oil from the Deepwater Horizon disaster