Eddies, Topography, and the Abyssal Flow by the Kyushu-Palau Ridge Near Velasco Reef

Andres, Magdalena; Siegelman, Mika; Hormann, Verena; Musgrave, Ruth; Merrifield, Sophia; Rudnick, Daniel L.; Merrifield, M. A.; Alford, Matthew H.; Voet, Gunnar; Wijesekera, H. W.; MacKinnon, Jennifer A.; Centurioni, Luca; Nash, Jonathan D.; Terrill, Eric

doi:10.5670/oceanog.2019.410

Cited by 9 publications

(3 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…They found that understanding the vorticity associated with the interactions of eddies on different temporal and spatial scales is important for ocean forecasting and more work needs to be done. Seasonal recirculation of the NECC to the NEC in relation to the Mindanao Dome (Masumoto and Yamagata 1991;Kashino et al 2011) and eddies associated with the recirculation patterns around Palau add to the complexity of the circulation (Kashino et al 2013;Andres et al 2019;Schönau et al 2019). These recent studies suggest that in situ observations are required for understanding the physical processes associated with flow past topography and for comparison with the models.…”

Section: Discussionmentioning

confidence: 99%

Current observations on and around a deep-ocean island/reef: northern Palau and Velasco Reef

Teague¹,

Wijesekera

Wang

et al. 2022

J Oceanogr

View full text Add to dashboard Cite

Current and hydrographic measurements were made in the equatorial Pacific Ocean between the westward-flowing North Equatorial Current and the eastward-flowing North Equatorial Counter Current. Nine moorings containing current profilers and hydrographic sensors were deployed on and around Velasco Reef, just north of Palau Island, from May 2016 to March 2017, when the Pacific Ocean was relaxing after the 2015/16 El Niño. Currents and their interactions with this abrupt bathymetric feature are characterized on spatial scales of 10–30 km, and frequencies from semidiurnal to intraseasonal. Currents near the reef displayed a two-layer structure and were not stationary due to the shifting of the major currents and eddy passages. Energy was significant at tidal and inertial periods, and at periods longer than ten days. Tides and higher frequency currents were responsible for about half the energy on the reef but for only about 20% of the energy in the deep water. Cyclonic (anticyclonic) vorticity occurred on the western (eastern) side of the reef during westward (eastward) flows, indicating recirculation on the leeward side of the reef. Vorticity west of the reef was much stronger than vorticity on the east side. When the cyclonic vorticity was large, the divergence flow patterns supported strong upwelling in the upper layer. Differences in both vertical and horizontal velocity coherences and correlations between moorings indicated that the reef affected the currents. The reef seemed to significantly impact water exchange. Currents near the reef are difficult to be described, particularly at depth by satellite products, making their prediction problematic.

show abstract

Section: Discussionmentioning

confidence: 99%

Current observations on and around a deep-ocean island/reef: northern Palau and Velasco Reef

Teague¹,

Wijesekera

Wang

et al. 2022

J Oceanogr

View full text Add to dashboard Cite

show abstract

“…6a). Slopes of the phase lines on this plot indicate that some of this variability is either propagating very rapidly across the entire basin (e.g., as barotropic Rossby waves; Andres et al 2012) or it is associated with large-scale zonal processes like seasonal heating and cooling. One particularly striking feature that stretches across much of the western basin, is a broadscale SSH sat increase by about 30 cm in early 2016.…”

Section: ) Satellite Sshmentioning

confidence: 99%

“…Prior to the standard processing, we subsample the RPIESs' pressure records to mimic the regular sampling schedule. The hourly records are each dedrifted using the method described in Andres et al (2005) to obtain corrected, hourly bottom pressures p at each of the eight sites, with p 5 p B_meas 2 p drift (e.g., Fig. A1, bottom).…”

Section: A Processing the Pies Recordsmentioning

confidence: 99%

On the Predictability of Sea Surface Height around Palau

Andres

Musgrave

Rudnick

et al. 2020

Journal of Physical Oceanography

Self Cite

View full text Add to dashboard Cite

As part of the Flow Encountering Abrupt Topography (FLEAT) program, an array of pressure-sensor equipped inverted echo sounders (PIESs) was deployed north of Palau where the westward-flowing North Equatorial Current encounters the southern end of the Kyushu-Palau Ridge in the tropical North Pacific. Capitalizing on concurrent observations from satellite altimetry, FLEAT Spray gliders and shipboard hydrography, the PIESs’ 10-month duration hourly bottom pressure (p) and round-trip acoustic travel time (τ) records are used to examine the magnitude and predictability of sea level and pycnocline depth changes and to track signal propagations through the array. Sea level and pycnocline depth are found to vary in response to a range of ocean processes, with their magnitude and predictability strongly process-dependent. Signals characterized here comprise the barotropic tides, semidiurnal and diurnal internal tides, southeastward propagating super-inertial waves, westward propagating mesoscale eddies, and a strong signature of sea level increase and pycnocline deepening associated with the region’s relaxation from El Niño to La Niña conditions. The presence of a broad band of super-inertial waves just above the inertial frequency was unexpected and the FLEAT observations and output from a numerical model suggest that these waves detected near Palau are forced by remote winds east of the Philippines. The PIES-based estimates of pycnocline displacement are found to have large uncertainties relative to overall variability in pycnocline depth, as localized deep current variations arising from interactions of the large-scale currents with the abrupt topography around Palau have significant travel time variability.

show abstract

Latitudinal gradient and influencing factors of deep-sea particle export along the Kyushu-Palau Ridge in the Philippine Sea

Wang,

Fang,

Yang

et al. 2024

Science of The Total Environment

View full text Add to dashboard Cite

Eddies, Topography, and the Abyssal Flow by the Kyushu-Palau Ridge Near Velasco Reef

Cited by 9 publications

References 18 publications

Current observations on and around a deep-ocean island/reef: northern Palau and Velasco Reef

Current observations on and around a deep-ocean island/reef: northern Palau and Velasco Reef

On the Predictability of Sea Surface Height around Palau

Latitudinal gradient and influencing factors of deep-sea particle export along the Kyushu-Palau Ridge in the Philippine Sea

Contact Info

Product

Resources

About