Simulations of acoustic tomography of ocean currents in a coastal region

1995 ◽  
Vol 98 (5) ◽  
pp. 2914-2914
Author(s):  
Oleg A. Godin ◽  
Dmitry Yu. Mikhin
Keyword(s):  
Coastal Region ◽  
Ocean Currents ◽  
Acoustic Tomography

Using acoustic tomography to monitor deep ocean currents in the eastern Gulf of Mexico

OCEANS 2009 ◽  
2009 ◽  
Author(s):  
D. A. Rosenfield ◽  
J. W. Caruthers ◽  
D. A. Nechaev ◽  
G. E. Ioup ◽  
J. W. Ioup ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Deep Ocean ◽  
Ocean Currents ◽  
Acoustic Tomography ◽  
Eastern Gulf Of Mexico ◽  
Deep Ocean Currents

scholarly journals Novel Method for the Estimation of Vertical Temperature Profiles Using a Coastal Acoustic Tomography System

2021 ◽  
Vol 8 ◽  
Author(s):  
Yeongbin Park ◽  
Chanhyung Jeon ◽  
Hajin Song ◽  
Youngseok Choi ◽  
Jeong-Yeob Chae ◽  
...  
Keyword(s):  
Temperature Profile ◽  
Coastal Region ◽  
Ocean Model ◽  
Acoustic Tomography ◽  
Observation Data ◽  
Random Errors ◽  
Vertical Temperature ◽  
Vertical Temperature Profile ◽  
Marine Aquaculture ◽  
Novel Method

Systems based on remote sensing technology, which use reciprocal acoustic signals to continuously monitor changes in the coastal oceanic environment, are referred to as coastal acoustic tomography (CAT) systems. These systems have been applied in regions in which heavy ship traffics, fishing and marine aquaculture activities make it difficult to establish in situ oceanic sensor moorings. Conventionally, CAT measurements were used to successfully produce horizontal maps of the depth-averaged current velocity and temperature in these coastal regions without attempting to produce a vertical temperature profile. This prompted us to propose a new method for vertical temperature profile estimation (VTPE) from CAT data using the available sea surface temperature (SST), near-bottom temperature (NBT), and water depth. The VTPE method was validated using data-assimilated and tide-included high-resolution ocean model outputs, including tide data, by comparing the estimated and simulated temperatures. Measurements were performed in the southern coastal region of Korea, where two CAT stations were moored to establish a continuous coastal ocean monitoring system. The validation results revealed that the algorithm performed well across all seasons. Sensitivity tests of the VTPE method with reasonable realistic random errors in the SST, NBT, and acoustic travel time measurements demonstrate that the method is applicable to CAT observation data because the monthly mean root-mean-squared difference (RMSD) for the vertical profiles for February, May, August, and November were 0.23, 0.30, 0.50, and 0.24°C, respectively. The VTPE method was applied to the CAT observation datasets acquired in February and August. The transceivers at the CAT stations were at depths 11 and 6 m on average. The RMSD between the estimated and observed temperatures in the middle layer (∼3 m depth) between two stations in February and August were 0.08 and 0.60°C, respectively, the accuracy of which is sufficient in largely time-varying coastal environments. We provide a novel method for continuous coastal subsurface environmental monitoring without interrupting maritime traffic, fishing, and marine aquaculture activities.

Mapping of ocean currents in shallow water using moving ship acoustic tomography

2019 ◽  
Vol 145 (2) ◽  
pp. 858-868 ◽  
Author(s):  
Chen-Fen Huang ◽  
Yun-Wen Li ◽  
Naokazu Taniguchi
Keyword(s):  
Shallow Water ◽  
Ocean Currents ◽  
Acoustic Tomography

scholarly journals Retrieval of coastal ocean currents using MCC technique on satellite imagery for supplementing altimeter derived currents

2014 ◽  
Vol XL-8 ◽  
pp. 1483-1489 ◽  
Author(s):  
P. Rajput ◽  
R. Ramakrishnan ◽  
A. S. Rajawat
Keyword(s):  
Suspended Sediment ◽  
Cross Correlation ◽  
Coastal Region ◽  
Surface Current ◽  
Coastal Ocean ◽  
Surface Flow ◽  
Ocean Currents ◽  
Coastal Currents ◽  
Error Statistics ◽  
Error Limit

Maximum Cross Correlation (MCC) technique have been used to derive coastal currents from sequential OCM derived suspended sediment concentration (SSC) maps and the MCC currents are integrated with the Ocean surface current analysis-Real time (OSCAR) ocean currents along the coastal regions of the Southern India. OSCAR currents are mainly depended on the oceanographic measurements from the satellite altimeter which have limitations in the coastal region and in representing the mesoscale properties dominating the coastal ocean. Sequential pair of atmospherically corrected and georeferenced OCM image is used to derive SSC, along the southern coast of India. Maximum Cross-Correlation (MCC) method is applied on the sequential time lapsed images of OCM for matching the suspended sediment dispersion patterns. The MCC technique involves computing of cross-correlation coefficients and identifying correlation peaks. The spatial change of the sediment pattern occurs due to the advection by the currents and the extent of the change corresponds to the speed and direction of the current. From the first image, template window is selected, which is searched in the second image within large region defined as the search window. The movement of the SSC pattern is calculated based on the maximum cross correlation in successive images. Error statistics are calculated between the spatially coherent MCC vectors and OSCAR currents. Based on statistical analysis, an error threshold of 30 degree for current direction and 0.06m/sec for current speed was given to MCC currents and MCC currents beyond the error limit are rejected, while the MCC current within the error limit is merged with the OSCAR ocean currents. The merging of MCC currents has spatially enhanced the OSCAR currents. MCC method is significant in calculating the coastal currents and its mesoscale properties, which dominate the coastal surface flow field and can be used in supplementing the OSCAR ocean currents. Merging of both the currents, have effectively resulted in preparing contiguous maps of coastal ocean currents.

scholarly journals Long-term acoustic tomography measurement of ocean currents at the northern part of the Luzon Strait

2010 ◽  
Vol 37 (7) ◽  
pp. n/a-n/a ◽  
Author(s):  
Naokazu Taniguchi ◽  
Arata Kaneko ◽  
Yaochu Yuan ◽  
Noriaki Gohda ◽  
Hong Chen ◽  
...  
Keyword(s):  
Luzon Strait ◽  
Ocean Currents ◽  
Acoustic Tomography

scholarly journals Cold Water Flow and Upper-Ocean Currents in the Bismarck Sea from December 2001 to January 2002

2011 ◽  
Vol 41 (4) ◽  
pp. 827-834 ◽  
Author(s):  
Takuya Hasegawa ◽  
Kentaro Ando ◽  
Hideharu Sasaki
Keyword(s):  
Papua New Guinea ◽  
Coastal Upwelling ◽  
Cold Water ◽  
Coastal Region ◽  
South Pacific ◽  
Ocean Currents ◽  
Upper Ocean ◽  
Thermal Change ◽  
Budget Analysis ◽  
Thermal Changes

Abstract The authors investigated the upper-ocean currents in the Bismarck Sea and related oceanic thermal changes in the western equatorial South Pacific for December 2001–January 2002; during this period, coastal upwelling occurred along the Papua New Guinea (PNG) coast. Southeastward and northwestward coastal currents toward the central PNG coast appeared along northern and southern PNG, respectively. In addition, westward currents extended toward central PNG in the southern part of the Bismarck Sea. A northeastward outflow toward the equator from the PNG coastal area, which is compensated for by such flows, was also found. Volume budget analysis in the upper ocean showed that, during the analysis period, the northeastward outflow ranged from +1.0 to +2.0 Sv (1 Sv ≡ 106 m3 s−1). This northeastward outflow brought relatively cool coastal water, which is related to PNG coastal upwelling, to the western equatorial South Pacific near PNG during this period. In addition, the upper-ocean temperature in this region showed a cooling tendency in line with a negative heat transport from the PNG coastal region. The present results indicate that northeastward transport of the cold water is related to the complicated upper-ocean currents in the Bismarck Sea and may have strongly affected the upper-ocean thermal change in the western equatorial Pacific near PNG for December 2001–January 2002.

Hormonal stimulation and some risk factors studied to improve bovine pregnancy rate at the Coastal areas of Barisal district of Bangladesh

2018 ◽  
Vol 52 (1-4) ◽  
pp. 22-30
Author(s):  
A K Paul ◽  
S M T Rahman
Keyword(s):  
Pregnancy Rate ◽  
Coastal Region ◽  
Hormonal Treatment ◽  
Coastal Areas ◽  
Pregnancy Rates ◽  
Hormonal Stimulation ◽  
Crossbred Cows ◽  
Treatment Groups ◽  
History Of ◽  
Group A

Hormonal treatment of cows at the coastal region of Barisal district of Bangladesh was performed to assess the improvement of pregnancy rate. A total of 100 cows and heifers with irregular history of cyclicity were selected randomly and divided into five treatment groups. The groups were A (treated with anthelmintic), B (treated with anthelmintic, vitamin ADE and multivitamin powder), C (treated with PGF2α), D (treated with GnRH) and E (treated with GnRH and PGF2α). Each group comprised of 20 animals. The age, breed and parity of experimental cows were considered during treatment. In the study, the cows treated with both GnRH and PGF2α (group E) showed significantly (p<0.05) higher estrus (80%) and pregnancy rate (60%) than that of group A, B, C and D. The overall estrus rates of local and crossbred cows were 64% and 70%, respectively and the pregnancy rates were 40 and 52%, respectively. The crossbred cows responded significantly (p<0.05) to hormonal treatment than that of local cows. Parity-2 cows showed higher estrus sign than that of other parities. However, the pregnancy rates were higher significantly (p<0.05) in parity-2 and parity ≥4 cows than that of parity-0, parity-1 and parity-3 cows. The pregnancy rate was also found higher in case of 4 to <5 years old cows than that of 2 to <3, 3 to <4, 5 to <6, and ≥6 years old. It may conclude that the hormonal regimen increases the pregnancy rate as well as decreases the undesired waiting of estrus and conception. Further study with more sample size will reveal the more effective treatment for cows at the coastal areas of Bangladesh.

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