scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2021 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels, which are characterized by a low salinity and high dissolved oxygen (DO) are observed by Seaglider in the main thermocline (26.0–27.0 sq) south of the Kuroshio Extension (KE), have horizontal and vertical scales of a few ten kilometers and a few ten meters, respectively. Water mass analyses revealed larger negative salinity anomalies (<−0.05) and positive DO anomalies (>15 μmol kg−1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (<26.7 σθ) while low salinity parcels appear in the lower layer (>26.7 sq). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a fast process for water mass migration via meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2020 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels with low salinity and high dissolved oxygen (DO) are observed in the main thermocline south of the Kuroshio Extension (KE). The Seaglider data, which was collected for four months beginning in late winter 2014 with fine spatial and temporal resolutions, identified small water parcels characterized by low salinity and high DO in the subsurface layer (26.0–27.0 σθ) with a few ten kilometers and a few ten meters in the horizontal and vertical scales, respectively. Water mass analyses revealed larger negative salinity anomalies (< − 0.05 PSS-78) and positive DO anomalies (> 15 µmol kg− 1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (< 26.7 σθ) while low salinity parcels appear in the lower layer (> 26.7 σθ). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a faster process for water mass migration by meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

AbstractSmall water parcels, which are characterized by a low salinity and high dissolved oxygen (DO) are observed by Seaglider in the main thermocline (26.0–27.0 σθ) south of the Kuroshio Extension (KE), have horizontal and vertical scales of a few tens of kilometers and a few tens of meters, respectively. Water mass analyses revealed larger negative salinity anomalies (<− 0.05) and positive DO anomalies (> 15 μmol kg−1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (< 26.7 σθ) while low salinity parcels appear in the lower layer (> 26.7 σθ). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in 1 month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a fast process for water mass migration via meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates that a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

scholarly journals Rapid water parcel transport across the Kuroshio Extension in the lower thermocline from dissolved oxygen measurements by Seaglider

2020 ◽  
Author(s):  
Shigeki Hosoda ◽  
Ryuichiro Inoue ◽  
Masami Nonaka ◽  
Hideharu Sasaki ◽  
Yoshikazu Sasai ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Dissolved Oxygen ◽  
Water Mass ◽  
Kuroshio Extension ◽  
Exchange Process ◽  
Surrounding Water ◽  
Small Water ◽  
Low Salinity ◽  
Mass Migration ◽  
The Kuroshio

Abstract Small water parcels, which are characterized by a low salinity and high dissolved oxygen (DO) are observed by Seaglider in the main thermocline (26.0–27.0 sq) south of the Kuroshio Extension (KE), have horizontal and vertical scales of a few ten kilometers and a few ten meters, respectively. Water mass analyses revealed larger negative salinity anomalies (<−0.05 PSS-78) and positive DO anomalies (>15 μmol kg−1) than those of the surrounding water. The characteristics are similar to those of water mass with low salinity and high DO in the subpolar Northwestern Pacific Ocean. Additionally, higher DO anomaly water parcels appear in the upper layer (<26.7 σθ) while low salinity parcels appear in the lower layer (>26.7 sq). Oxygen consumption rates from the apparent oxygen utility suggest that the small water parcels consume less oxygen than the surrounding water, implying that they migrate in a shorter time across the KE after subduction and their characteristics may reflect the sea surface temperature, salinity, and DO in the subduction region. Similar small water parcels represented by high-resolution numerical simulations indicate that they pass through the KE in one month. The simulations support the oxygen consumption rate from the Seaglider observations. The existence of a fast process for water mass migration via meso- and submesoscale subduction processes across the KE affects the amount, subduction, and exchange process of water mass. Our study indicates a small water mass contributes to the exchange process across the KE rapidly, which had not been identified in previous studies. Consequently, detailed observations using multiple Seagliders should capture detailed spatial and temporal variability of the water mass exchange process.

scholarly journals Ventilation revealed by the observation of dissolved oxygen concentration south of the Kuroshio Extension during 2012–2013

2016 ◽  
Vol 72 (6) ◽  
pp. 837-850 ◽  
Author(s):  
Akira Nagano ◽  
Toshio Suga ◽  
Yoshimi Kawai ◽  
Masahide Wakita ◽  
Kazuyuki Uehara ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Kuroshio Extension ◽  
Dissolved Oxygen Concentration ◽  
The Kuroshio

Cold air outbreak over the Kuroshio extension region

OCEANS 2009 ◽  
2009 ◽  
Author(s):  
T. G. Jensen ◽  
T. Campbell ◽  
T. A. Smith ◽  
R. J. Small ◽  
R. Allard
Keyword(s):  
Kuroshio Extension ◽  
Cold Air ◽  
Cold Air Outbreak ◽  
The Kuroshio ◽  
Kuroshio Extension Region

scholarly journals Variability of the nutrient stream near Kuroshio's origin

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chen-Tung Arthur Chen ◽  
Ting-Hsuan Huang ◽  
Chi-Hsuan Wu ◽  
Haiyan Yang ◽  
Xinyu Guo
Keyword(s):  
Pacific Ocean ◽  
Continental Shelf ◽  
East China Sea ◽  
Kuroshio Extension ◽  
Subsurface Water ◽  
East China ◽  
The East China Sea ◽  
High Productivity ◽  
China Sea ◽  
The Kuroshio

AbstractThe Kuroshio—literally “the Black Stream”—is the most substantial current in the Pacific Ocean. It was called the Black Stream because this oligotrophic current is so nutrient-poor in its euphotic zone that the water appears black without the influence of phytoplankton and the associated, often colored dissolved organic matter. Yet, below the euphotic layer, nutrient concentrations increase with depth while current speed declines. Consequently, a core of maximum nutrient flux, the so-called nutrient stream, develops at a depth of roughly between 200 and 800 m. This poorly studied nutrient stream transports nutrients to and supports high productivity and fisheries on the East China Sea continental shelf; it also transports nutrients to and promotes increased productivity and fisheries in the Kuroshio Extension and the subarctic Pacific Ocean. Three modes of the Kuroshio nutrient stream are detected off SE Taiwan for the first time: one has a single-core; one has two cores that are apparently separated by the ridge at 120.6–122° E, and one has two cores that are separated by a southward flow above the ridge. More importantly, northward nutrient transports seem to have been increasing since 2015 as a result of a 30% increase in subsurface water transport, which began in 2013. Such a nutrient stream supports the Kuroshio's high productivity, such as on the East China Sea continental shelf and in the Kuroshio Extension SE of Japan.

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