Frontal Waves in the East of the Tsugaru Strait Revealed by the High-Frequency Radar Observation DOI Creative Commons
Hitoshi Kaneko, Takahiro Tanaka, Hiroto Abe

et al.

Research Square (Research Square), Journal Year: 2021, Volume and Issue: unknown

Published: June 29, 2021

Abstract Surface velocity observations of the eastern part Tsugaru Strait made by high-frequency radar revealed frequent occurrence frontal waves along axis Warm Current in 2017–2019. The current (maximum zonal meridional direction) disturbed north–south direction with period ~ 13.7 days that is dominant timescale tide modulation strait, addition to 27.3 days. amplitude fluctuation increased downstream direction, from neck channel (~ 141.0°E) outlet strait adjacent Pacific Ocean 141.5°E). propagation speed disturbance was slower than due surface advection especially seasons when stratification developed, and agreed well estimated theory based on two-layer baroclinic instability model except for winter. at 141.5°E) could cause short-term (from 20 1 month) variations an anticyclonic gyre developed east summer autumn reported previous studies.

Language: Английский

Rapid increase of surface water pCO2 revealed by settling particulate organic matter carbon isotope time series during 2001–2009 in Sagami Bay, Japan DOI
Yoshihisa Mino, Chiho Sukigara, Atsushi Watanabe

et al.

Journal of Oceanography, Journal Year: 2023, Volume and Issue: 79(3), P. 317 - 331

Published: April 11, 2023

Language: Английский

Citations

2
Protist dynamics in the eastern Tsugaru Strait, Japan from 2010 to 2018: Implications for the relationship between decadal climatology and aquaculture production DOI Creative Commons
Koji Sugie, Masahide Wakita,

Shoko Tatamisashi

et al.

Environmental Research, Journal Year: 2023, Volume and Issue: 244, P. 115691 - 115691

Published: May 19, 2023

Environmental changes such as seasonality, decadal oscillation, and anthropogenic forcing may shape the dynamics of lower trophic-level organisms. In this study, 9-years (2010-2018) monitoring data on microscopic protists diatoms dinoflagellates, environmental variables were analyzed to clarify relationships between plankton local/synoptic changes. We found that time-series temperature increased in May, whereas it decreased August November. Nutrients (e.g., phosphate) remained unchanged August, November from 2010 2018. The partial pressure CO

Language: Английский

Citations

2
Development of a high-resolution marine ecosystem model for predicting the combined impacts of ocean acidification and deoxygenation DOI Creative Commons
Lawrence Patrick C. Bernardo, Masahiko Fujii, Tsuneo Ono

et al.

Frontiers in Marine Science, Journal Year: 2023, Volume and Issue: 10

Published: Sept. 27, 2023

An approach was developed to help evaluate and predict the combined effects of ocean acidification deoxygenation on calcifying organisms along coast Japan. The Coastal Regional Ocean COmmunity (CROCO) modeling system set up couple Modeling System (ROMS) Pelagic Interaction Scheme for Carbon Ecosystem Studies (PISCES) biogeochemical model used reproduce physical biochemical processes in area around Miyako Bay, Iwate Prefecture, Future scenario cases were also up, which initial boundary conditions based Projection (FORP) simulations. Present day simulations able general features observed parameters, except some rapid decreases salinity, pH aragonite saturation state (Ω arag ). This suggests that more local factors have not been introduced into model, such as submarine groundwater discharge, may be involved, or river inputs underestimated. Results future projections suggest a significant impact global warming worst case climate change under Representative Concentration Pathway (RCP) 8.5 scenario. In particular, it is feared values Ω would critical level < 1.1) throughout year, decreased larval shell lengths malformation experimentally locally grown Haliotis discus hannai (Ezo Abalone) species. However, these findings true different coastal locality, this study highlights continues stress importance developing setups capable incorporating both regional affecting deoxygenation.

Language: Английский

Citations

2
Subinertial frequency variations in the axis of the Tsugaru Warm Current east of the Tsugaru Strait DOI Creative Commons
Hitoshi Kaneko, Takahiro Tanaka, Hiroto Abe

et al.

Progress in Earth and Planetary Science, Journal Year: 2022, Volume and Issue: 9(1)

Published: Oct. 15, 2022

Abstract The eastern part of the Tsugaru Strait (located at ~ 41.5° N) is a remarkable region coastal flow system around Japan due to Warm Current (TgWC), an intensive eastward current that flows over its complex topography and exhibits marked tidal variation. TgWC has jetlike structure demonstrates drastic seasonal changes in path vertical structure. Using high-resolution dataset obtained from high-frequency radar (HFR) data assimilation experiment (JCOPE-T DA), we focused on frontal variation, which shorter than timescale, along axis relation meanders jet. We found variations with multiple timescales between 1 14 days, especially summer autumn. 14-day occurrence west side Strait, was consistent variation strait. zonal scale meander estimated by HFR matched several times larger internal deformation radius, JCOPE-T DA outputs showed crest such greater depths progresses surface. also suggested instabilities, indicating potential kinetic energy conversion mean eddy field. propagation speed several-day two-layer baroclinic instability. relatively high coherence wind autumn, during time strait switched easterly westerly. These imply effect north–south water mass mixing strait, including rapid acidification intensification stratification.

Language: Английский

Citations

4
Deep-sea bottom-water environment change caused by sediment resuspension on the continental slope off Sanriku, Japan, before and after the 2011 Tohoku Earthquake DOI Creative Commons
Masahide Wakita,

Shuichi Watanabe,

Jun Yoshino

et al.

Progress in Earth and Planetary Science, Journal Year: 2022, Volume and Issue: 9(1)

Published: Oct. 22, 2022

Abstract The 2011 off the Pacific coast of Tohoku Earthquake occurred southern Sanriku, Japan, on March 11 and generated strong shaking huge tsunami along entire eastern Tohoku. mainshock numerous large aftershocks caused mass-wasting sedimentation events continental shelf, slope, trench bottom. To investigate impacts deep-sea bottom-water environment we conducted shipboard surveys up to ~ 2000 dbar during 2011–2018 long-term monitoring seafloor slope using a station (~ 1000 dbar) Otsuchi Bay 2012–2018. high turbidity (maximum 6%) was observed for bottom water deeper than 500 area Sanriku This by sporadic sediment resuspension induced frequent aftershocks. Furthermore, dissolved oxygen concentrations in layer from 1500 dropped significantly about 10% after earthquake, while nutrients inorganic carbon showed no significant changes but exhibited wide variations. associated with increase phosphate, carbon, methane, as well decrease those nitrate. suggests that remineralization suspended organic matter resulting respiration denitrification microbial communities earthquake chemical properties bottom-water. change maintained due continued likely variations phosphate. There are two peaks concentration isotope ratio methane near hypocenter, which were advected isopycnal surfaces 27.38σ θ (1000 27.56σ (1500 dbar). source shallower peak input is considered be shallow Graphical abstract

Language: Английский

Citations

4
Seasonal changes in the protist communities of Hakodate Bay, southern Hokkaido, from 2020 to 2022 DOI
Yusuke Hamao,

Kyosei Morimoto,

Shoko Tatamisashi

et al.

Regional Studies in Marine Science, Journal Year: 2024, Volume and Issue: 78, P. 103775 - 103775

Published: Aug. 27, 2024

Language: Английский

Citations

0
Interannual sea-level variation around mainland Japan forced by subtropical North Pacific wind and its possible impact on the Tsugaru warm current DOI
Akira Nagano, Hitoshi Kaneko, Masahide Wakita

et al.

Ocean Dynamics, Journal Year: 2023, Volume and Issue: 73(12), P. 761 - 771

Published: Nov. 9, 2023

Language: Английский

Citations

1
Comment on bg-2023-80 DOI Creative Commons
Tsuneo Ono, Daisuke Muraoka, Masahiro Hayashi

et al.

Published: July 19, 2023

Abstract. The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, these forcings can change along with global climate change. Understanding the mechanism variation in each area is thus important for a realistic future projection that considers changes forcings. From 2020 to 2021, we performed parallel year-round observations related ocean parameters at five stations around Japanese coast (Miyako Bay, Shizugawa Kashiwazaki Coast, Hinase Archipelago, Ohno Strait) understand characteristics short-term variations their Annual variability (~1 standard deviation) aragonite saturation state (Ωara) were 0.05–0.09 0.25–0.29, respectively, three areas low anthropogenic loadings Bay), while it increased 0.16–0.21 0.52–0.58, two medium (Hinase Archipelago Strait Seto Inland Sea). Statistical assessment temporal various timescales revealed most annual variabilities both Ωara derived by timescale < 10 days, rather than seasonal-scale variation. Our analyses further illustrated was caused thermodynamic processes equally contributed Ωara. observed results showed acidification 1.5 occurred occasionally Miyako Bays, frequently Strait. Most acidified events low-salinity events. amplitude linearly correlated salinity variation, its regression coefficient time high freshwater input positively nutrient concentration main river flows into area.

Language: Английский

Citations

0
Responses to comments from Reviewer 1 DOI Creative Commons
Tsuneo Ono

Published: Aug. 16, 2023

Abstract. The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, these forcings can change along with global climate change. Understanding the mechanism variation in each area is thus important for a realistic future projection that considers changes forcings. From 2020 to 2021, we performed parallel year-round observations related ocean parameters at five stations around Japanese coast (Miyako Bay, Shizugawa Kashiwazaki Coast, Hinase Archipelago, Ohno Strait) understand characteristics short-term variations their Annual variability (~1 standard deviation) aragonite saturation state (Ωara) were 0.05–0.09 0.25–0.29, respectively, three areas low anthropogenic loadings Bay), while it increased 0.16–0.21 0.52–0.58, two medium (Hinase Archipelago Strait Seto Inland Sea). Statistical assessment temporal various timescales revealed most annual variabilities both Ωara derived by timescale < 10 days, rather than seasonal-scale variation. Our analyses further illustrated was caused thermodynamic processes equally contributed Ωara. observed results showed acidification 1.5 occurred occasionally Miyako Bays, frequently Strait. Most acidified events low-salinity events. amplitude linearly correlated salinity variation, its regression coefficient time high freshwater input positively nutrient concentration main river flows into area.

Language: Английский

Citations

0
Responses to comments from Reviewer 2 DOI Creative Commons
Tsuneo Ono

Published: Aug. 16, 2023

Abstract. The pH of coastal seawater varies based on several local forcings, such as water circulation, terrestrial inputs, and biological processes, these forcings can change along with global climate change. Understanding the mechanism variation in each area is thus important for a realistic future projection that considers changes forcings. From 2020 to 2021, we performed parallel year-round observations related ocean parameters at five stations around Japanese coast (Miyako Bay, Shizugawa Kashiwazaki Coast, Hinase Archipelago, Ohno Strait) understand characteristics short-term variations their Annual variability (~1 standard deviation) aragonite saturation state (Ωara) were 0.05–0.09 0.25–0.29, respectively, three areas low anthropogenic loadings Bay), while it increased 0.16–0.21 0.52–0.58, two medium (Hinase Archipelago Strait Seto Inland Sea). Statistical assessment temporal various timescales revealed most annual variabilities both Ωara derived by timescale < 10 days, rather than seasonal-scale variation. Our analyses further illustrated was caused thermodynamic processes equally contributed Ωara. observed results showed acidification 1.5 occurred occasionally Miyako Bays, frequently Strait. Most acidified events low-salinity events. amplitude linearly correlated salinity variation, its regression coefficient time high freshwater input positively nutrient concentration main river flows into area.

Language: Английский

Citations

0