Theoretical fluctuation predictions for low-frequency acoustical propagation ranges of 25 to 107 km in the 2009-2010 Philippine Sea experiment

2012 ◽  
Vol 131 (4) ◽  
pp. 3354-3354
Author(s):  
Rex Andrew ◽  
Andrew White ◽  
James Mercer ◽  
Peter Worcester ◽  
Matthew Dzieciuch ◽  
...  
Keyword(s):  
Low Frequency ◽  
Philippine Sea

Vertical directionality of low‐frequency ambient noise in the Philippine Sea.

2010 ◽  
Vol 128 (4) ◽  
pp. 2387-2387
Author(s):  
Kathleen E. Wage ◽  
Matthew A. Dzieciuch ◽  
Peter F. Worcester
Keyword(s):  
Ambient Noise ◽  
Low Frequency ◽  
Philippine Sea

scholarly journals Observations of low-frequency, long-range acoustic propagation in the Philippine Sea and comparisons with mode transport theory

2020 ◽  
Vol 147 (2) ◽  
pp. 877-897
Author(s):  
Tarun K. Chandrayadula ◽  
Sivaselvi Periyasamy ◽  
John A. Colosi ◽  
Peter F. Worcester ◽  
Matthew A. Dzieciuch ◽  
...  
Keyword(s):  
Long Range ◽  
Transport Theory ◽  
Low Frequency ◽  
Acoustic Propagation ◽  
Philippine Sea

Measured low frequency intensity fluctuations over a 107 km path in the 2009-2010 Philippine Sea experiment

2012 ◽  
Vol 131 (4) ◽  
pp. 3354-3354
Author(s):  
Andrew W. White ◽  
Rex K. Andrew ◽  
James A. Mercer ◽  
Peter F. Worcester ◽  
Matthew A. Dzieciuch
Keyword(s):  
Low Frequency ◽  
Philippine Sea ◽  
Intensity Fluctuations ◽  
Frequency Intensity

State estimates and forecasts of the northern Philippine Sea circulation including ocean acoustic travel times

2021 ◽  
Author(s):  
Ganesh Gopalakrishnan ◽  
Bruce D. Cornuelle ◽  
Matthew R. Mazloff ◽  
Peter F. Worcester ◽  
Matthew A. Dzieciuch
Keyword(s):  
General Circulation ◽  
Mesoscale Eddy ◽  
Low Frequency ◽  
Circulation Model ◽  
The State ◽  
Sea Surface ◽  
Massachusetts Institute Of Technology ◽  
Travel Times ◽  
Philippine Sea ◽  
Institute Of Technology

AbstractThe 2010–2011 North Pacific Acoustic Laboratory (NPAL) Philippine Sea experiment measured travel times between six acoustic transceiver moorings in a 660–km diameter ocean acoustic tomography array in the Northern Philippine Sea (NPS). The travel-time series compare favorably with travel times computed for a yearlong series of state estimates produced for this region using the Massachusetts Institute of Technology general circulation model–Estimating the Circulation and Climate of the Ocean four-dimensional variational (MITgcm-ECCO 4DVAR) assimilation system constrained by satellite sea surface height and sea surface temperature observations and by Argo temperature and salinity profiles. Fluctuations in the computed travel times largely match the fluctuations in the measurements caused by the intense mesoscale eddy field in the NPS, providing a powerful test of the observations and state estimates. The computed travel times tend to be shorter than the measured travel times, however, reflecting a warm bias in the state estimates. After processing the travel times to remove tidal signals and extract the low-frequency variability, the differences between the measured and computed travel times were used in addition to SSH, SST, and Argo temperature and salinity observations to further constrain the model and generate improved state estimates. The assimilation of the travel times reduced the misfit between the measured and computed travel times, while not increasing the misfits with the other assimilated observations. The state estimates that used the travel times are more consistent with temperature measurements from an independent oceanographic mooring than the state estimates that did not incorporate the travel times.

Low-frequency pulse propagation over 510 km in the Philippine Sea: A comparison of observed and theoretical pulse spreading

2016 ◽  
Vol 140 (1) ◽  
pp. 216-228 ◽  
Author(s):  
Rex K. Andrew ◽  
Andrew Ganse ◽  
Andrew W. White ◽  
James A. Mercer ◽  
Matthew A. Dzieciuch ◽  
...  
Keyword(s):  
Pulse Propagation ◽  
Low Frequency ◽  
Philippine Sea ◽  
Frequency Pulse

scholarly journals Interannual Variations of Subsurface Spiciness in the Philippine Sea: Observations and Mechanism

2012 ◽  
Vol 42 (6) ◽  
pp. 1022-1038 ◽  
Author(s):  
Yuanlong Li ◽  
Fan Wang ◽  
Fangguo Zhai
Keyword(s):  
North Pacific ◽  
Low Frequency ◽  
Phase Changes ◽  
Enso Cycle ◽  
Western Boundary ◽  
Ekman Pumping ◽  
Wind Stress Curl ◽  
Central Pacific ◽  
Philippine Sea ◽  
Salinity Changes

Abstract The Philippine Sea (PS) is a key region connecting North Pacific subtropics to the equator via western boundary currents. Using available measurements from Argo profiling floats, satellite altimeters, and research surveys, the authors investigate the characteristics and mechanism of subsurface spiciness variability (represented by salinity changes between 23.5 and 24.5 σθ) in the PS. During the past decade, low-frequency salinity variability was dominated by interannual signals characterized by out-of-phase changes between the southern and northern PS with peak-to-peak amplitudes exceeding 0.1 psu. These salinity anomalies are mainly generated locally by anomalous cross-front geostrophic advections. In 2003, an anomalous cyclonic circulation developed in the PS, which transported greater (less) than normal high-salinity North Pacific Tropical Water to the northern (southern) PS and produced positive (negative) salinity anomalies there. In 2009, an anomalous anticyclone emerged, which produced negative (positive) salinity anomalies in the northern (southern) PS. These year-to-year variations are closely associated with ENSO cycle. During strong El Niño (La Niña) episodes, positive (negative) wind stress curl anomalies between 8° and 18°N evoke westward-propagating upwelling (downwelling) Rossby waves in the central Pacific and positive (negative) anomalous Ekman pumping in the western Pacific, resulting in the observed current and salinity changes in the PS. Further analysis suggests that these locally generated spiciness anomalies disperse quickly while propagating to the equatorial Pacific in the Mindanao Current (MC). In the meantime, anomalies advected from higher latitudes are nearly diminished upon reaching the PS. The western boundary of the North Pacific seems quite efficient in damping extratropical signals.

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