Article
Geosciences, Multidisciplinary
Tiago S. Dotto, Mauricio M. Mata, Rodrigo Kerr, Carlos A. E. Garcia
Summary: The northern Antarctic Peninsula (NAP) is a dynamic transitional zone affected by intense climate change, with water masses mainly originating from the Bellingshausen and Weddell seas. Limited understanding of the region's water masses and dynamic processes is attributed to sparse data coverage. The novel NAPv1.0 data set presented in this work provides a valuable tool for studying climatological changes in the NAP region.
EARTH SYSTEM SCIENCE DATA
(2021)
Article
Meteorology & Atmospheric Sciences
Junying Zhu, Jie Shi, Xinyu Guo
Summary: This study investigated the interannual variation of the bottom cold water mass (INCWM) in Iyo-Nada, Japan, from 1994 to 2015 and its response to air-sea heat flux change. The study found that the average water temperature of INCWM showed a negative correlation with its area and the interannual variation of INCWM was more sensitive to air-sea heat flux during the warming season.
Article
Oceanography
Yusuke Hamao, Kohei Matsuno, Yoko Mitani, Atsushi Yamaguchi
Summary: This study evaluated the species composition and spatial distribution of nano- and micro-protist communities in the southern part of the Okhotsk Sea off Hokkaido during the summer. The results showed that different water masses had distinct effects on the abundance and distribution of these communities.
JOURNAL OF OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Seung-Tae Yoon, JongJin Park
Summary: The East/Japan Sea is a natural laboratory for studying global Meridional Overturning Circulation (MOC) changes. Investigations into winter sea surface temperature (SST) variations are important for characterizing and predicting the East Sea MOC. However, global SST products need to be corrected and optimized for local conditions. A warm bias in cold SSTs was identified in three SST products, and a correction method incorporating Argo float data was suggested. The correction method significantly reduced biases and improved SST data quality.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Chelsea A. Korpanty, Leon Hoffman, Rodrigo da Costa Portilho-Ramos, Juergen Titschack, Claudia Wienberg, Dierk Hebbeln
Summary: Framework-forming scleractinian corals in cold-water areas are important for supporting biodiversity hotspots. This study investigated the impact of habitat variability on diversity over geologic time using sediment cores from a coral reef in the Alboran Sea. It was found that habitat spatial patterns had a significant influence on molluscan diversity.
FRONTIERS IN MARINE SCIENCE
(2023)
Review
Pharmacology & Pharmacy
Yiwen Shou, Chao Feng, Qinpei Lu, Xin Mao, Huisha Huang, Zhiheng Su, Hongwei Guo, Zhaoquan Huang
Summary: Due to their unique properties and activities, marine biological resources are important for producing health products, food, and cosmetics. Collagen, which accounts for approximately 70% of sea cucumber body wall, has small-molecule polypeptides with diverse biological functions. Understanding the composition and structure of sea cucumber polypeptides will aid in the development of these resources.
FRONTIERS IN PHARMACOLOGY
(2023)
Article
Meteorology & Atmospheric Sciences
Kazumasa Sengoku, Hideo Takahashi, Fumiaki Fujibe, Hiroshi G. Takahashi
Summary: This study statistically investigates the climatological characteristics of cold-air damming (CAD) on the Kanto Plain. The results show that CAD is most frequent in autumn and strong CAD is more frequent in the cold season. The long-term trend in CAD frequency is not obvious. CAD with precipitation tends to be stronger and CAD without precipitation is more frequent at night. Six different patterns of synoptic fields in CAD cases are identified based on long-term reanalysis data.
INTERNATIONAL JOURNAL OF CLIMATOLOGY
(2023)
Article
Environmental Sciences
Andrew Loh, Donghwi Kim, Joon Geon An, Narin Choi, Un Hyuk Yim
Summary: Studies on the land-sea-air interactions of aerosols, which play a significant role in global environmental changes, are scarce. In this study, we investigated potential sources of sub-micron aerosols over the East Sea and measured their chemical compositions using a high-resolution aerosol mass spectrometer. The results showed higher aerosol concentrations in industrialized coastal areas compared to offshore regions. Five distinct sources of aerosols were identified, and the spatiotemporal variation of MSA and MSA:SOa- over the East Sea were determined for the first time.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Geochemistry & Geophysics
Andrey A. Sorokin, Victor A. Zaika, Nikolai M. Kudryashov
Summary: The study reveals three stages of granitic magmatism in the eastern Mongol-Okhotsk Belt: Cambrian, Middle Devonian, and Late Permian-Early Triassic. The granites show distinct geochemical signatures, suggesting different tectonic settings for their formation.
Article
Environmental Sciences
Tetsuya Matsunaka, Seiya Nagao, Mutsuo Inoue, Rodrigo Mundo, Saki Tanaka, Ning Tang, Masa-aki Yoshida, Masanori Nishizaki, Masaya Morita, Tetsutaro Takikawa, Nobuo Suzuki, Shouzo Ogiso, Kazuichi Hayakawa
Summary: This study monitored the concentrations of phase-partitioned polycyclic aromatic hydrocarbons (PAHs) in seawater off Oki Island, Japan, from 2015 to 2019, aiming to understand the seasonal variations, main sources, and transport pathways of PAHs in the southwestern Sea of Japan. The results showed that combustion products were the main sources of both dissolved and particulate PAHs. Higher concentrations of PAHs were observed in summer-autumn, and it was found that the area around southern Oki Island was impacted by PAH-rich summer continental-shelf water transported by the Tsushima Warm Current flowing from the East China Sea.
MARINE POLLUTION BULLETIN
(2022)
Article
Environmental Sciences
Mahmoud Pirooznia, Mehdi Raoofian Naeeni, Alireza Atabati, Mohammad J. Tourian
Summary: This study aims to improve the sea surface current predictions in the Persian Gulf and the Oman Sea by calibrating the MIKE 21 numerical ocean model. The calibration process involved assimilating the model with altimetry and hydrographic observations, and optimizing the weights of the objective functions using metaheuristic optimization methods. The results showed that the calibration led to a significant improvement in the model's accuracy, allowing for more accurate evaluations of model parameters and potential applications such as electricity generation.
Article
Engineering, Environmental
Masato Ito, Kay I. Ohshima, Yasushi Fukamachi, Genta Mizuta, Yoshimu Kusumoto, Takashi Kikuchi
Summary: This study used ADCP backscatter data to examine the suspension depth of frazil ice in the Sea of Okhotsk. It was found that frazil ice can extend down the water column to capture seafloor sediment at depths up to 35 meters, indicating a significant role in the bio-related material cycle.
COLD REGIONS SCIENCE AND TECHNOLOGY
(2021)
Article
Food Science & Technology
Michela Pellegrini, Lucilla Iacumin, Jelka Pleadin, Greta Kresic, Elisabetta Orecchia, Andrea Colautti, Ana Vulic, Nina Kudumija, Cristian Bernardi, Giuseppe Comi
Summary: The aim of this study was to investigate the microbial and physico-chemical characteristics of cold smoked sea bass (CSSB), a novel italian fish product. The results showed the presence of bacterial contamination from raw materials, the environment, and the production process. High levels of lactic acid bacteria (LAB) and total bacteria count (TBC) were observed during storage, but did not significantly affect the total volatile basic nitrogen (TVB-N). Pathogenic bacteria were not detected. Cold smoked sea bass offers high nutritional value and excellent microbial quality, making it a beneficial food source.
Article
Food Science & Technology
Wenmin Ji, Man Li, Tianbao Yang, Hongyan Li, Wenxiang Li, Jing Wang, Meng Ma
Summary: Cold plasma treatment can promote the germination of soybean seeds and enhance the biomass and nutritional content of soybean sprouts.
FOOD RESEARCH INTERNATIONAL
(2022)
Article
Engineering, Marine
Yuliya Koudryashova, Tatiana Chizhova, Mutsuo Inoue, Kazuichi Hayakawa, Seiya Nagao, Evgeniya Marina, Rodrigo Mundo
Summary: This study examined the vertical distribution of polycyclic aromatic hydrocarbons (PAHs) in the Japan Basin in the Sea of Japan. The highest concentration of PAHs was found in the mesopelagic realm, likely due to deep convection and/or subduction of intermediate water, as well as the biogeochemical setting in the western Japan Basin. Dissolved PAHs were more prevalent than particulate PAHs at all depths, and hydrophobicity played a role in the distribution of higher-molecular-weight PAHs. The flux calculations showed that biological pumps and overturning circulation contribute equally to removing PAHs from the deep waters of the Japan Basin.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Limnology
Kuo Hong Wong, Hajime Obata, Taejin Kim, Yoshiko Kondo, Jun Nishioka
Summary: This study provides new insights into the biogeochemical cycling of Cu in the subarctic Pacific based on chemical speciation and size fractionation analyses. The research shows that Cu in the subarctic Pacific is strongly bound to organic ligands of various sizes and binding strengths throughout the water column, with different characteristics at different depths.
LIMNOLOGY AND OCEANOGRAPHY
(2021)
Review
Oceanography
Youhei Yamashita, Tetsu Tosaka, Rise Bamba, Ryuichi Kamezaki, Shuji Goto, Jun Nishioka, Ichiro Yasuda, Toru Hirawake, Joji Oida, Hajime Obata, Hiroshi Ogawa
Summary: The study highlights the Sea of Okhotsk as the major source region of allochthonous FDOM in the North Pacific Intermediate Water (NPIW), rather than the Bering Sea. Allochthonous FDOM derived from shelf sediments in the Sea of Okhotsk is conservatively distributed throughout the North Pacific via the circulation of intermediate water, especially the upper part of NPIW. Furthermore, the study demonstrates that FDOM can aid in determining the spatiotemporal distribution of NPIW and its mixing with other water masses in the deep ocean.
PROGRESS IN OCEANOGRAPHY
(2021)
Article
Multidisciplinary Sciences
Youhei Yamashita, Motohiro Nakane, Yutaro Mori, Jun Nishioka, Hiroshi Ogawa
Summary: The study reveals the distribution of dissolved black carbon in the Pacific Ocean, indicating a negative correlation between its concentration and deep-ocean circulation. The removal process of black carbon to abyssal sediments is estimated to account for a small percentage of anthropogenic CO2 uptake by the ocean.
NATURE COMMUNICATIONS
(2022)
Article
Oceanography
Kuo Hong Wong, Jun Nishioka, Taejin Kim, Hajime Obata
Summary: In this study, comprehensive distributions of dissolved manganese (dMn) in the subarctic Pacific were presented and compared with the data of dissolved iron (dFe) in the same region. The study revealed different vertical profiles for dMn and dFe and observed different forms in the size fractionation of these two micronutrients. The transport distances of dMn found in this study were the highest in the Pacific region, and this long-range transport could potentially impact phytoplankton growth through upwelling processes.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Review
Oceanography
Jun Nishioka, Ichiro Yasuda, Toru Hirawake, Tomohiro Nakamura, Yoshiko Kondo, Yuri N. Volkov
Summary: The memorial addresses for Mr. Alexey Fedorovich Shcherbinin and Captain Evgeniy Anikovich Sklizkov highlight their significant roles and leadership in Russian-Japanese collaborative expeditions, expressing deep condolences and honoring their achievements.
PROGRESS IN OCEANOGRAPHY
(2022)
Review
Oceanography
Dong Yan, Jun Nishioka, Takenobu Toyota, Koji Suzuki
Summary: The Sea of Okhotsk plays a key role in the seawater circulation of the North Pacific Ocean. During winter, sea ice forms in the northern shelf and is transported to the southern part of the sea by the East Sakhalin Current. Diatoms are the dominant microalgae in the sea ice ecosystem, with Thalassiosira spp., Porosira glacialis, and Fragilariopsis cylindrus being the major species. The presence of the East Sakhalin Current influences the composition and abundance of microalgae in the seawater stations, with higher concentrations of dissolved Fe and ammonia. The study suggests that the winter phytoplanktonic communities in the southern Sea of Okhotsk are largely dependent on the presence of the East Sakhalin Current.
PROGRESS IN OCEANOGRAPHY
(2022)
Article
Environmental Sciences
Hirofumi Tazoe, Hajime Obata, Takuya Hara, Mutsuo Inoue, Takahiro Tanaka, Jun Nishioka
Summary: For the first time, the vertical activity concentration distributions of radium isotopes, Ra-226 and Ra-228, were obtained in the western Subarctic Pacific Gyre (WSAG). The distributions were influenced by upwelling of deeper water, vertical mixing, and lateral transport.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Oceanography
Ryosuke Futsuki, Toru Hirawake, Amane Fujiwara, Hisatomo Waga, Takashi Kikuchi, Shigeto Nishino, Tomonori Isada, Koji Suzuki, Yutaka W. Watanabe
Summary: This study evaluated the optical and productivity data in the Arctic Ocean during summer and autumn and investigated the performance and sensitivity of absorption-based algorithms. The results showed that the methods had little bias for in situ input parameters and reflectance, but there were problems with estimating quantum yield from only optical parameters.
JOURNAL OF OCEANOGRAPHY
(2022)
Article
Limnology
Shunyan Cheung, Kailin Liu, Kendra A. Turk-Kubo, Jun Nishioka, Koji Suzuki, Michael R. Landry, Jonathan P. Zehr, Szeki Leung, Lixia Deng, Hongbin Liu
Summary: Recent studies have found active nitrogen fixation in high-latitude waters, but the ecological controls on nitrogen-fixing organisms in such systems are still unclear. This study detected abundant UCYN-A, a nitrogen-fixing cyanobacteria, in the Gulf of Anadyr and identified a correlation between its abundance and the ratio of dissolved iron to dissolved inorganic nitrogen. The study also found selective grazing of UCYN-A in nitrogen-depleted waters and highlighted the importance of the Fe : DIN ratio in determining the abundance of UCYN-A in high-latitude waters.
LIMNOLOGY AND OCEANOGRAPHY LETTERS
(2022)
Article
Meteorology & Atmospheric Sciences
Kaori Kawana, Yuzo Miyazaki, Yuko Omori, Hiroshi Tanimoto, Sara Kagami, Koji Suzuki, Youhei Yamashita, Jun Nishioka, Yange Deng, Hikari Yai, Michihiro Mochida
Summary: This study conducted a cruise observation in the western North Pacific to characterize atmospheric aerosols and gaseous air/seawater compounds. The results showed high variability in size distribution and cloud condensation nuclei (CCN) activity of aerosols from different sources.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Environmental Sciences
Naoya Kanna, Shin Sugiyama, Takuto Ando, Yefan Wang, Yuta Sakuragi, Toya Hazumi, Kohei Matsuno, Atsushi Yamaguchi, Jun Nishioka, Youhei Yamashita
Summary: An increasing body of work has shown the potential impacts of subglacial discharge from marine-terminating glaciers on the marine environment around Greenland. Upwelling of nutrients associated with rising buoyant plumes near the front of marine-terminating glaciers plays a key role in maintaining the high productivity of connected fjords. However, the response of protist communities to subglacial discharges into fjords remains poorly understood.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Limnology
Kailin Liu, Jun Nishioka, Bingzhang Chen, Koji Suzuki, Shunyan Cheung, Yanhong Lu, Huijun Wu, Hongbin Liu
Summary: This study investigates phytoplankton growth and microzooplankton grazing, two critical processes in marine food webs, in the subarctic western Pacific and the Bering Sea. Results show that phytoplankton growth is primarily determined by nutrient availability and temperature. In the high-nutrient, low-chlorophyll regions, iron availability is the limiting factor. In the Gulf of Anadyr and Kamchatka Strait, phytoplankton growth is mainly limited by inorganic nitrogen. Microzooplankton grazing rate is influenced by temperature and prey availability. The study reveals different food web structures in areas with and without riverine iron input.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Oceanography
Takenobu Toyota, Noriaki Kimura, Jun Nishioka, Masato Ito, Daiki Nomura, Humio Mitsudera
Summary: The sea ice in the southern Sea of Okhotsk has significant impacts on freshwater input and primary production, but its interannual variability is not well understood yet. Long-term field observations and satellite data analysis revealed that the sea ice in this region is uncorrelated with that in the northern and central regions, and its thickness and volume are mainly controlled by dynamical pile-up processes, rather than the thermodynamical freezing conditions.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Environmental Sciences
Youhei Yamashita, Jun Nishioka
Summary: Through circulation of intermediate water, the marginal seas have been identified as important external sources of dissolved iron (Fe) in the North Pacific. This study presents comprehensive spatial distributions of dissolved Fe concentrations and Fe(III) solubilities over the North Pacific, including the marginal seas, the Sea of Okhotsk, and the Bering Sea. The results suggest that the major dissolved Fe chemical form derived from shelf and slope sediments in the marginal seas changed from colloidal Fe to FDOMH-Fe complexes.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2023)
Article
Environmental Sciences
Atsushi Ooki, Keita Minamikawa, Fanxing Meng, Naoya Miyashita, Toru Hirawake, Hiromichi Ueno, Yuichi Nosaka, Tetsuya Takatsu
Summary: Elevated methyl and ethyl iodide concentrations in bottom waters may be linked to diatom aggregates and phytodetritus settling to the sea floor. Dark incubation experiments suggest that diatom aggregates are a source of methyl and ethyl iodide to the ambient water. These findings reveal that phytodetritus at the seafloor is a potential source of volatile organic iodine compounds in polar and subpolar coastal oceans.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
