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Journal of Oceanography
Journal Prestige (SJR): 0.989  Citation Impact (citeScore): 2 Number of Followers: 12  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1573-868X - ISSN (Online) 0916-8370 Published by Springer-Verlag  [2468 journals]
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- Kuroshio surface water intrusion into the eastern part of the transition
domain: its pathways and decadal variations-
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Abstract: The quasi-stationary jets, called “J1” and “J2” in the western North Pacific Ocean, transport the warm and salty waters originating from the Kuroshio and form the transition domain (TD) between the subtropical and subarctic features. Although previous studies have revealed the Kuroshio water pathways from the Kuroshio Extension to the western part of the TD through J1, the pathways to the eastern part of the TD (ETD) have not been revealed yet. We use the backward particle-tracking method to evaluate the Kuroshio water pathways from the Kuroshio Extension to the ETD. Our results identify that the Kuroshio Extension Northern Branch is the dominant pathway. The subarctic Front, the main jet of the Kuroshio Extension, and J1 also contribute to the Kuroshio water intrusion with the aid of eddy transports. We also find that the Kuroshio water intrusion affects the decadal sea surface temperature and surface heat flux variations. When the Kuroshio water intrusion is enhanced, the heat transport into the transition domain from the Kuroshio Extension and the heat release to the atmosphere from the transition domain are enhanced. The decadal variation of Kuroshio water intrusion correlates with the J2 strength and not with the Kuroshio Extension latitude. Using the Hilbert Empirical Orthogonal Function, we show that the remote force in the Gulf of Alaska and the central North Pacific Ocean possibly drives the decadal variation of J2 strength. In addition to this remote mechanism, the geostrophic anomalies forced by the local wind stress anomalies are also important.
PubDate: 2025-05-17
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- Air-sea oxygen fluxes in mid-latitude western North Pacific quantified by
the array of biogeochemical Argo floats-
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Abstract: The oxygen fluxes between the atmosphere and ocean were quantified using Argo profiling floats equipped with a RINKO oxygen sensor in the western North Pacific (24°–46°N, 127°–166°E) from 2021 to 2023. Oxygen was significantly undersaturated in winter, particularly in the subtropical mode water formation region, due to the increase in oxygen solubility with cooling and the entrainment of deep water into the surface mixed layer. On the other hand, oxygen was supersaturated during almost all seasons except in winter in all latitudinal ranges. This is due to primary production and decrease in saturation levels caused by the increase in water temperature in spring and summer. Additionally, during autumn when water temperature drops, the entrainment of subsurface oxygen maxima into the surface mixed layer further contributed to surface oxygen supersaturation and oceanic oxygen emission. Surface apparent oxygen utilization exhibited significant short-term fluctuations (> 10 μmol kg−1) on timescales of several days especially in winter and spring. Similar fluctuations in the fluxes were estimated primarily in winter, corresponding to higher wind speeds, and to a lesser extent in spring, characterized by weaker winds. While oxygen tended to be absorbed at higher latitudes and released at lower latitudes, there was significant variation in fluxes within the same latitudinal range. Annual fluxes were strongly influenced by winter sea surface conditions characterized by high wind speeds. Moreover, the varying wind speeds during winter exerted a notable influence on the interannual variability of the oxygen fluxes.
PubDate: 2025-05-09
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- Spatial structure of rain pool observed on the Kuroshio and Baiu fronts in
the East China Sea-
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Abstract: Spatial three-dimensional structure of low-salinity water on the Baiu and Kuroshio fronts is shown using intensive observation results by three ships in the East China Sea. The surface low-salinity pool along the Kuroshio front was formed by rainfall of the Baiu front during the observations. The horizontal distribution of the low-salinity pool with about 130 km long, 40 km wide, and 9–12 m thick along the Kuroshio front is consistent with the precipitation map of the weather radar. The relationship between the surface low-salinity water and precipitation was also quantitatively explained by the conservation of volume. Barrier layer below the surface rain pool had a thickness from several meters to a maximum of 46 m. Subsurface (~ 20-m depth) low-salinity patches were observed below the barrier layer. Based on the order of vertical flow, it is considered that the low-salinity patches moved from the sea surface to the subsurface layer in about 1 day, and their origin is presumed to be rainfall several days earlier. Below the low-salinity patches, we detected temperature inversion layer with warm and saline water, which is thought to have an effect similar to the barrier layer.
PubDate: 2025-05-07
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- Journal of Oceanography Most Cited Paper Award 2025
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PubDate: 2025-04-25
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- Intercomparison of bias of global sea surface temperature products
associated with tropical cyclone passages in the western North Pacific-
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Abstract: Sea surface temperature (SST) is crucial for tropical cyclones (TCs). However, accurately capturing SST responses to TCs using satellite-based products remains challenging. Nevertheless, such SST products are frequently used in TC studies. This study compared six SST products during TC passages in the western North Pacific from September 1, 2007 to December 31, 2021, and characterized their spatiotemporal differences. Composite analyses of 355 TC cases revealed that SST differences between products increased during TC passages, with mean differences ranging from 0.1 to 1 °C one day after TC passage. These differences were particularly pronounced in the case of larger surface cooling, when TCs were decaying. Similar characteristics were confirmed through comparison with in situ observations, mainly using drifting buoys. Further investigation into the spatiotemporal variation in bias showed that the SST bias of most products, except for J-OFURO3 SST, fluctuated significantly during TC passages. J-OFURO3 SST had the smallest spatiotemporal variation in bias among the six products. This is because the J-OFURO3 SST is an ensemble median of multiple SST products based on satellite observations and includes data without spatiotemporal interpolation in its ensemble members. This study also evaluated higher temporal resolution data from ERA5 hourly skin temperature. However, the characteristics of this product were similar to those of the daily satellite-based products, with the issue of more pronounced temporal bias variations observed during TC passages. These findings underscore the importance of careful SST product selection in TC research and provide valuable insights for the further development of satellite-based SST products.
PubDate: 2025-04-14
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- High-turbidity bottom mixed-layer water on the shelf off Hokkaido in the
Okhotsk Sea: distribution, seasonal variations, and spreading-
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Abstract: The Okhotsk Sea coast of Hokkaido and the Kuril Basin exhibit high primary production, supported by nutrient supply through material circulation. As part of this circulation, we focused on high turbidity water in the bottom mixed layer (BML) on the shelf off Hokkaido and its spreading. Our observations in spring and autumn showed a thick, high-turbidity BML across the shelf, originating mostly from the Soya Strait and flowing toward the Shiretoko Peninsula and into the Kuril Basin. Analysis of past observation data and an ocean model output revealed that the thick BML was present year-round, suggesting the continuous supply of high-turbidity waters. BML thickness and density were highest in spring and lowest in winter and peaked offshore of the Soya Warm Current. Using the model output, we conducted Lagrangian tracking of BML water. BML waters with low density mostly flowed into the North Pacific quickly through shallow straits near Hokkaido, whereas higher-density BML waters spread into the Kuril Basin, remaining there longer before eventually flowing into the North Pacific through deep straits. We also showed seasonal variations primarily driven by density variations, interannual changes associated with flow field variation, and sensitivity to sinking rates for sinking particles. The results suggest that high-turbidity bottom waters off Hokkaido in the Okhotsk Sea are transported to the Kuril Basin and North Pacific, potentially impacting material circulation and ecosystems. In particular, high-turbidity waters lighter than 26.7 σθ may be entrained into the euphotic zone by winter mixing, contributing to the next spring bloom.
PubDate: 2025-04-12
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- Northeast Pacific marine heatwaves link climate modes in a coupled model
simulation-
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Abstract: Coupled atmosphere–ocean phenomena known as northeast Pacific marine heatwaves (MHWs) simulated in a climate model with an eddy-permitting ocean model were examined. During the analyzed 270-years of the preindustrial control run, 13 events of MHW (defined here by warm annual-mean SST anomalies with over 1.5 times of the standard deviation) were detected. The simulated MHWs are linked to the decadal-scale climate modes of PDO, inverted NPGO (IV-NPGO), and the central Pacific El Niño (CP-El-Niño): IV-NPGO and then PDO changed the signs from negative to positive a few years before the MHWs at around which PDO took the maxima, when CP-El-Niño occurred. Air–sea interactions between subtropical-tropical and within mid-latitudes suggest playing crucial roles in the evolution of the MHWs.
PubDate: 2025-04-11
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- Impact of sea surface temperature anomalies in the East China Sea and
western subtropical pacific on the august 2021 Northern Kyushu heavy
precipitation-
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Abstract: The effects of extratropical sea surface temperature (SST) heterogeneity on various atmospheric phenomena have received much attention recently. In this study, the effects of SST anomalies on heavy precipitation that occurred in northern Kyushu Island, Japan, in August 2021 are investigated with a convection–permitting regional atmospheric model. The mid–August SST anomalies are found to provide the following favorable conditions for the intense precipitation. Mesoscale cyclones and associated moisture fluxes intensified over a warm SST anomaly in the northern East China Sea (ECS). The vertical shear of horizontal winds also intensified over a pair of warm and cool SST anomalies in the eastern ECS. The SST anomaly in the western subtropical North Pacific affected the static stability of the air parcels entering the precipitation area. The air parcels became more unstable even though they passed over the cool SST anomalies south of the precipitation area. This seemingly counterintuitive result can be explained by the stability of the atmospheric boundary layer (ABL) and the height of the air parcels. The less unstable ABL over the cool SST anomaly kept the air parcels at lower altitudes, and thus they tended to be more susceptible to the influence of heat fluxes from the sea surface and, therefore, becoming more unstable. The results of this study thus provide new insight into the role of the complex SST distribution during heavy precipitation events in extratropics, suggesting the need for further studies to deepen our understanding of the atmospheric responses to the extratropical SST.
PubDate: 2025-04-04
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- Kuroshio volume transport over the past 3 decades estimated from combined
satellite altimetry and hydrography data-
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Abstract: Time series of Kuroshio transport across a section off Shikoku, Japan are derived. Fluctuations of the whole eastward transport are primarily caused by an offshore local stationary anticyclonic eddy. In contrast, throughflow transport, excluding the eddy’s contribution, reflects variations of western-boundary transport expected to compensate for interior Sverdrup transport (WBST). The mean throughflow transport is considerably smaller than the mean WBST. Throughflow transport exhibits a long-term decreasing trend, consistent with WBST. On an interannual scale, throughflow transport lags behind WBST by approximately 5 years. Mean throughflow transports during large meander periods and non-largemeander periods are almost the same.
PubDate: 2025-04-04
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- The Kuroshio large meander and its various impacts: a review
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Abstract: The Kuroshio south of Japan exhibits bimodal variations between large meander (LM) and non-LM paths. The Kuroshio LM drastically changes the distribution of currents and water temperature in the surface and subsurface layers, affecting atmospheric conditions, marine ecosystems, and fisheries resources. The most recent Kuroshio LM event occurred in August 2017 and is still continuing as of March 2025 (LM2017). Through studies of the long-lived LM2017, many new insights into the Kuroshio LM and its impact have been gained in recent years. This study aims to organize and share our current understanding of the Kuroshio LM and its impacts by reviewing past and present studies. Future directions for research on the Kuroshio LM and its impacts are also presented. This review advances the literature by covering not only the oceanic dynamics of the Kuroshio LM, but also its impacts on ocean conditions, atmospheric phenomena, lower ecosystems, and fisheries resources, thereby presenting the first attempt at such a comprehensive review of the Kuroshio LM.
PubDate: 2025-03-29
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- Sensitivity of the Arctic sea ice representation to the ice thickness
category resolution in an OGCM-
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Abstract: The sea ice representation in ocean and climate models must be improved to better understand and predict the global climate system. Here, we investigate the sensitivity of the large-scale sea ice field to the resolution of the sea ice thickness distribution (ITD) categories used by an ocean general circulation model (OGCM). We conduct a baseline experiment with the five widely used thickness categories and a series of sensitivity experiments with higher resolutions for thick, middle, and thin ice sections of the ITD. Increasing the resolutions of the thick and middle ITD sections had little effect, but increasing the resolution of the thin ice section caused a marked increase in the Arctic sea ice volume (by about 10% of the absolute summertime volume). In that experiment, both subgrid-scale transport from thin to thicker ice in winter and openings in the thin ice cover were enhanced, easing ice movement and deformation in the melting season and increasing the amount of thicker multi-year ice. This accumulated multi-year ice affected the total Arctic sea ice volume interannually. Adding more thin ice categories to the conventional five categories improved the representation of the observed lognormal ice thickness distribution when the OGCM used a simple ice strength formulation, whereas in previous studies using a nonlinear ice strength formulation, a high-resolution ITD unrealistically reduced ice strength in the central Arctic. We expect our results to be useful in the development of sea ice models and the evaluation of international ensemble climate predictions.
PubDate: 2025-03-17
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- Impact of Eighteen Degree Water thickness variation on the thermal and
biogeochemical structure in the euphotic layer-
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Abstract: It has been recently found that North Pacific Subtropical Mode Water impacts the overlying thermal structure by uplifting the isotherms when it thickens. How the thickness variation of North Atlantic Subtropical Mode Water, also known as Eighteen Degree Water (EDW), affects the overlying thermal and biogeochemical structure through such uplifting effect has been investigated using Argo float data and shipboard observation data at Bermuda Atlantic Time-series Study site. When EDW was thicker, the overlying isotherms were uplifted, leading to a decrease in temperature centered at 50–100 dbar in the warm season; in addition, the oxycline existing around 100 dbar and the nitracline at 100–150 dbar also tended to be uplifted, leading to an increase of apparent oxygen utilization and nitrate concentrations in the lower euphotic layer; furthermore, there is a tendency that chlorophyll-a maximum around 100 dbar shallowed, and primary production integrated in the euphotic layer increased during the spring bloom season. Thus, although the core of thicker EDW tends to have less nitrate as shown by previous studies, thicker EDW tends to increase biological production in the euphotic layer through the enhanced uplifting effect.
PubDate: 2025-03-08
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- Status and prospects of biogeochemical Argo observations of chlorophyll-a
in the northwest Pacific-
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Abstract: Biogeochemical Argo (BGC-Argo) floats are autonomous marine observing platforms that monitor chlorophyll-a and other indicators of ocean ecosystem health globally. Since 2018, there has been an increase in the number of chlorophyll-a observations in the northwest Pacific due to the deployment of BGC-Argo floats. Such progress offers an unprecedented opportunity to develop a skillful operational ocean biogeochemical model. Here, we assess the performance of BGC-Argo floats in measuring chlorophyll-a concentrations and their spatiotemporal structures via comparison with satellite and shipboard data. Results show a good correlation (r = 0.61) between the float and satellite observations and an excellent correlation (r = 0.87) between the satellite and shipboard observations of sea surface concentrations. The float data have a bias of about 0.04 mg m−3 or 59 % with respect to the satellite observations. Rare matchups between the float and shipboard observations of winter and summer profiles in the upper 200 m reveal an excellent correlation (r = 0.86), demonstrating the reliability of the vertical structure obtained from these floats. Concurrent two-year time series from five BGC-Argo floats reveal the prevalence of subsurface chlorophyll-a maxima in the subtropical northwest Pacific that can persist throughout the year. These findings stress the importance of subsurface monitoring to better quantify biological productivity and carbon export. We discuss the status of BGC-Argo floats in the northwest Pacific and recommend possible directions for modelling work and deployment efforts in achieving the proposed global array of 1000 floats in this decade, which has significant potential to improve predictability.
PubDate: 2025-02-28
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- Dominant contribution of Arctic sea ice cover to the bimodally interannual
variation of the polar night jet in late November-
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Abstract: The polar night jet (PNJ), characterized by strong zonal-mean zonal winds at 60–80° N and 50 hPa, shows interannual variability that is distinctively observed in late November. The autumnal acceleration tendency of the PNJ exhibits the alternative of monotonous acceleration and temporary deacceleration marked by a “short break” and consequently represents bimodal fluctuations. Statistical analyses using reanalysis and objective analysis datasets in this study reveal that the reduction of Arctic sea ice concentration (SIC) predominantly contributes to the PNJ short break, rather than other potential factors such as the quasi-biennial oscillation (QBO) and the El Niño-Southern Oscillation (ENSO) variability. The PNJ short break is usually accompanied by the upward propagation of Rossby waves from the troposphere to the stratosphere over Siberia. When the Arctic SIC is lower than climatology, particularly in the Barents–Kara Sea, the increased heat flux at the sea surface causes deceleration events inherent to late November. In contrast, the intensity of the submonthly-scale PNJ deceleration and acceleration is affected little by the phase of the QBO, while the phase of the QBO is thought to contribute to the seasonal means of the PNJ. While ENSO variability can also give favorable conditions for the deceleration of the zonal-mean westerly winds, the upward wave propagation is observed mainly over the North Atlantic and Europe rather than over Siberia.
PubDate: 2025-02-22
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- The behaviour of nickel, copper, zinc, and cadmium in the subarctic
Pacific Ocean: East–West differences-
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Abstract: Nickel (Ni), copper (Cu), zinc (Zn), and cadmium (Cd) are trace metals classified as nutrient-type elements in the oceans. This study reports the full-depth distribution of dissolved (d) Ni, Cu, Zn, and Cd during the 2017 GEOTRACES Japan KH-17-3 cruise, aiming to augment the knowledge of chemical oceanography of the nutrient-type elements and highlight the east–west differences in the subarctic Pacific Ocean. The linear relationship of dCd and PO4 reflects a concurrent influence of ocean circulation and biogeochemical cycling. For the other metals, the dM/PO4 ratios reflect preferential uptake by phytoplankton, fluvial inputs, reversible scavenging, and release from the bottom. The east–west differences in the dM/PO4 ratios suggest supplies of Ni and Cu from marginal seas and the North American continent. East–west gradient of the dZn/PO4 ratio shows severer depletion of dZn in the surface water of the eastern subarctic Pacific, which is consistent with previous research. We calculate the enrichment factor (EF) that is the dM/dAl ratio normalised with the M/Al ratio in the crust for dNi, dCu, dZn, and dCd. The EF values are substantially high in the central part of the Subarctic Gyre, implying the presence of anthropogenic atmospheric input via the westerly wind.
PubDate: 2025-02-15
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- Fukushima-derived radiocesium tracks the mode waters in the western
subtropical area of the North Pacific-
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Abstract: Radiocesium released from the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) in 2011 resulted in radioactive contamination in the North Pacific Ocean. A portion of the FNPP1-derived radiocesium settled in the North Pacific had been transported by the mode waters, the subtropical mode water (STMW) and central mode water (CMW). We measured radiocesium concentration in the western subtropical area from 2015 to 2021 and revealed the temporal changes in the FNPP1-derived radiocesium by 2021. The FNPP1-derived radiocesium circulated along the anti-cyclonic circulation of STMW within the western subtropical area in the time-scale of 3‒6 years. During the circulation, the inventory of the FNPP1-derived radiocesium in the western subtropical area decreased with the time constant of 4‒8 years, which agrees with the renewal time of STMW. The inventory was estimated to be 4.6 ± 1.8 PBq in 2017‒2018 and 3.3 ± 1.1 PBq in 2019‒2021. We also observed the FNPP1-derived radiocesium in the western tropical area for the first time in 2020. It is suggested that the FNPP1-derived radiocesium in the western tropical area had not been transported southward from the western subtropical area but eastward from the subarctic/subtropical boundary area in the eastern North Pacific. In that case, the approximate 1.3 PBq of the inventory loss in the western region was probably transported to the eastern region within the western subtropical area between 2017‒2018 and 2019‒2021. The FNPP1-derived radiocesium will be usable for studies on the thermocline circulations in the North Pacific Ocean in the future.
PubDate: 2025-02-15
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- Influence of extreme northward meandered Kuroshio Extension during
2023–2024 on ocean–atmosphere conditions in the Sanriku offshore
region, Japan-
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Abstract: The ocean off the Sanriku coast, Japan, where the Kuroshio Extension (KE) meets the Oyashio, has unique dynamics and hosts rich marine resources. Since April 2023, the KE, typically flowing eastward around 36°N, exhibited an extreme northward meander, reaching 40°N by the winter of 2024. An anticyclonic eddy pinched off from the KE’s northern edge in late May 2024. The Japan Meteorological Agency conducted hydrographic surveys that cross this eddy and the KE along about 145°E in late May 2024. The hydrographic data revealed that thick warm-salty subtropical water replaced the cold-fresh subarctic water off the Sanriku coast, with temperatures 10 °C warmer at depths of 50–400 dbar compared to past decades. The Subtropical Mode Water, characterized by vertical uniformity, existed north of 40°N, more than 500 km further north of its conventional distribution area. From April 2023 to August 2024, satellite data indicated record-high sea surface temperature off the Sanriku coast (+ 4.9 °C), with intense marine heatwave conditions almost every day. In the winter of 2024, over the very warm ocean off the Sanriku coast, 300 W m–2 more heat than usual in the form of turbulent heat flux was released from the ocean to the atmosphere, and air temperature and humidity increased up to around 800 hPa level, from atmospheric reanalysis data. In addition to monitoring these unprecedented ocean conditions off the Sanriku coast, it is important to assess their impact on the marine environment, fisheries, and, ultimately, the local economy.
PubDate: 2025-02-13
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- Development of Eucampia zodiacus blooms associated with salinity
stratification in Ariake Bay during winter-
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Abstract: To elucidate the mechanism of winter diatom blooms in Ariake Bay, particularly Eucampia zodiacus Ehrenberg blooms, field observations of the entire bay and observations using an automated observation buoy system at a fixed point were conducted from November 2018 to March 2019. Chaetoceros spp., Skeletonema spp., and E. zodiacus blooms were observed during the study period. The vertical distribution of the physical parameters in Ariake Bay showed that vertical mixing occurred throughout the bay from November to December. In contrast, density stratification gradually occurred in the inner part of the bay from February as precipitation and water temperature increased. Monitoring data from automated observation buoys showed that salinity stratification occurred during neap tides in February, and the blooms of E. zodiacus developed during this event. Although E. zodiacus was distributed throughout the water column, the vertical distribution of dissolved oxygen indicated that it increased in the upper mixed layer. However, populations in the bottom layer may be transported inshore to estuaries via estuarine circulation. In summary, the formation of salinity stratification owing to increased river discharge from February and the associated estuarine circulation are essential factors in developing E. zodiacus blooms.
PubDate: 2025-02-05
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- HYCOM-ECOSMO for the Indian Ocean: a simulation of oxygen minimum zone
variability over the last two decades-
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Abstract: The Arabian Sea oxygen minimum zone (OMZ) has the smallest horizontal area of all open ocean OMZs but is the world's third most intense OMZ with the largest vertical extent. This study used a regional physical-biogeochemical coupled model, HYbrid Coordinate Ocean Model- ECOSystem (HYCOM-ECOSMO), to investigate the variations in Arabian Sea OMZ and deoxygenation for the period 2000–2020. The model was evaluated against BGC-Argo data and World Ocean Atlas 2018 (WOA18) to check the consistency of eddy-permitting simulation. It accurately simulated dissolved oxygen (DO) profiles, with RMSE of 16.5 µmol kg−1 for WOA18 and 21 µmol kg−1 for BGC-Argo. Model efficiency was estimated at 0.81 with percentage bias of 31% indicating that model performs well with observations. Interannual and seasonal variabilities showed good agreement with BGC-Argo profiling floats, but with slight DO overestimation. Despite a slight decreasing trend in the model's OMZ DO, Argo data indicated a minor increase. Sensitivity experiments identified detritus remineralization and sinking rates as key factors influencing DO levels. Surface DO, temperature, and Brunt-Väisälä frequency showed spatial warming impacts. OMZ exhibited seasonal variation, with higher DO concentrations during the winter monsoon due to convective mixing. ENSO and Indian Ocean Dipole (IOD) phases minimally influence surface DO levels, with lagged impacts (1–10 months) on temperature, productivity, organic matter sinking, and microbial respiration. The system responds more promptly to IOD than to ENSO. These findings establish a baseline for future research on marine ecosystems, fishery and regional climate projections in the Arabian Sea.
PubDate: 2025-02-01
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- Experimental study of the effect of slope topography on the optical remote
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Abstract: The internal breaking and waveform inversion of the depression internal solitary waves (ISWs) over slope-shelf have been observed in many laboratory experiments and field studies. However, it is difficult to match the data of ISWs of field measurement with remote sensing observation data, and the variation of optical remote sensing imaging characteristics during the propagation of ISWs on the continental slope is still unknown. In this paper, based on the observation results of 50 groups of ISWs in 32 remote sensing images during the climbing process, laboratory physical simulation is carried out to simulate the evolution of ISWs crossing the slope-shelf in the flume and obtain the optical images. The results show that when ISWs propagate on the slope-shelf, the waveform gradually becomes asymmetric, the front edge of ISWs becomes gentle, and the back edge of ISWs becomes steep, and the amplitude of ISWs will become smaller. The imaging effect of stripes of ISWs in optical images will become worse as ISWs propagate on the slope, and the relative gray value difference and the brightness-darkness distance will also become smaller, which is consistent with the variations of the optical imaging characteristics of ISWs extracted from the remote sensing image. In addition, the stratification ratios of water layers affect the optical imaging characteristics of ISWs with the same initial energy.
PubDate: 2025-01-24
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