Temporal patterns in detections of sperm whales (Physeter macrocephalus) in the North Pacific Ocean based on long-term passive acoustic monitoring

2014 ◽  
Vol 136 (4) ◽  
pp. 2153-2153
Author(s):  
Karlina Merkens ◽  
Anne Simonis ◽  
Erin Oleson
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Passive Acoustic Monitoring ◽  
The North ◽  
Passive Acoustic ◽  
The North Pacific

Increasing anthropogenic nitrogen in the North Pacific Ocean

Science ◽  
2014 ◽  
Vol 346 (6213) ◽  
pp. 1102-1106 ◽  
Author(s):  
Il-Nam Kim ◽  
Kitack Lee ◽  
Nicolas Gruber ◽  
David M. Karl ◽  
John L. Bullister ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Limited Region ◽  
The North ◽  
Term Change ◽  
Rate Of Increase ◽  
Anthropogenic Nitrogen ◽  
The North Pacific

The recent increase in anthropogenic emissions of reactive nitrogen from northeastern Asia and the subsequent enhanced deposition over the extensive regions of the North Pacific Ocean (NPO) have led to a detectable increase in the nitrate (N) concentration of the upper ocean. The rate of increase of excess N relative to phosphate (P) was found to be highest (∼0.24 micromoles per kilogram per year) in the vicinity of the Asian source continent, with rates decreasing eastward across the NPO, consistent with the magnitude and distribution of atmospheric nitrogen deposition. This anthropogenically driven increase in the N content of the upper NPO may enhance primary production in this N-limited region, potentially leading to a long-term change of the NPO from being N-limited to P-limited.

scholarly journals Trends of the Pathways and Intensities of Surface Equatorial Current System in the North Pacific Ocean

2016 ◽  
Vol 29 (18) ◽  
pp. 6693-6710 ◽  
Author(s):  
Yi-Chia Hsin
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Current System ◽  
North Equatorial Current ◽  
Ocean Reanalysis ◽  
The North ◽  
Equatorial Current ◽  
The North Pacific

Abstract An ensemble of ocean reanalysis products is utilized to quantify the long-term tendencies of pathways and along-pathway transports of the three surface equatorial currents (North Equatorial Current, North Equatorial Countercurrent, and northern branch of the South Equatorial Current) in the North Pacific Ocean during the period of the 1900s–2000s. This study uses 12 ocean reanalysis products in the ensemble for the period after the 1960s, while only 2 Simple Ocean Data Assimilation (SODA) products are taken into consideration for the period prior to 1960s. The analyses indicate that the three currents in the western (eastern) Pacific Ocean have more southern (northern) mean central positions and tend to move southward (northward) over the past 100 years. All three currents have weakening tendencies, with the exception of the North Equatorial Current having intensified in the western Pacific Ocean. The Sverdrup dynamics, which directly relates the wind-driven circulation in the interior ocean to wind stress curl and Earth rotation, can be applied to simply address the long-term changes of intensities and pathways of the three surface currents in the tropical North Pacific Ocean.

scholarly journals Neural Network Approach to Retrieving Ocean Subsurface Temperatures from Surface Parameters Observed by Satellites

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 388
Author(s):  
Hao Cheng ◽  
Liang Sun ◽  
Jiagen Li
Keyword(s):  
Neural Network ◽  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Sea Surface ◽  
Satellite Measurements ◽  
Surface Parameters ◽  
The North ◽  
The North Pacific ◽  
Bpnn Model

The extraction of physical information about the subsurface ocean from surface information obtained from satellite measurements is both important and challenging. We introduce a back-propagation neural network (BPNN) method to determine the subsurface temperature of the North Pacific Ocean by selecting the optimum input combination of sea surface parameters obtained from satellite measurements. In addition to sea surface height (SSH), sea surface temperature (SST), sea surface salinity (SSS) and sea surface wind (SSW), we also included the sea surface velocity (SSV) as a new component in our study. This allowed us to partially resolve the non-linear subsurface dynamics associated with advection, which improved the estimated results, especially in regions with strong currents. The accuracy of the estimated results was verified with reprocessed observational datasets. Our results show that the BPNN model can accurately estimate the subsurface (upper 1000 m) temperature of the North Pacific Ocean. The corresponding mean square errors were 0.868 and 0.802 using four (SSH, SST, SSS and SSW) and five (SSH, SST, SSS, SSW and SSV) input parameters and the average coefficients of determination were 0.952 and 0.967, respectively. The input of the SSV in addition to the SSH, SST, SSS and SSW therefore has a positive impact on the BPNN model and helps to improve the accuracy of the estimation. This study provides important technical support for retrieving thermal information about the ocean interior from surface satellite remote sensing observations, which will help to expand the scope of satellite measurements of the ocean.

scholarly journals Nursery origin and population connectivity of swordfish Xiphias gladius in the North Pacific Ocean

2021 ◽  
Author(s):  
R. J. David Wells ◽  
Veronica A. Quesnell ◽  
Robert L. Humphreys ◽  
Heidi Dewar ◽  
Jay R. Rooker ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Population Connectivity ◽  
The North ◽  
Xiphias Gladius ◽  
The North Pacific
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