Article
Geosciences, Multidisciplinary
Mingfang Miao, Zhiwei Zhang, Bo Qiu, Zhiyu Liu, Xincheng Zhang, Chun Zhou, Shoude Guan, Xiaodong Huang, Wei Zhao, Jiwei Tian
Summary: Based on 2-year moored measurements in the northeastern South China Sea, this study quantified the contributions of multiscale dynamic processes to steric height at 60 m. The analysis showed that different dynamic processes have different relative contributions to steric height, and their effects vary seasonally.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Hideharu Sasaki, Bo Qiu, Patrice Klein, Masami Nonaka, Yoshikazu Sasai
Summary: Recent studies have reported the impacts of oceanic submesoscale circulations on oceanic circulation, marine ecosystem, and air-sea heat flux. This study shows the interannual variations of active submesoscale circulations in winter and their mechanism in the subtropical northeastern Pacific. The submesoscale kinetic energy varies synchronously with the available potential energy release in a process of mixed layer instability (MLI), and El Nino events appear to modulate the interannual variations.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Oceanography
Shihong Wang, Zhenya Song, Weidong Ma, Qi Shu, Fangli Qiao
Summary: Submesoscale turbulence (1-50 km) plays a key role in the ocean energy cascade, functioning as an intermit between geostrophic-balanced mesoscale eddies and three-dimensional dissipation. In this study, the mesoscale and submesoscale turbulence in the upper ocean and the kinetic energy cascade between them are investigated using the output of a simulation. The inverse kinetic energy cascade, through which mesoscale kinetic energy is transferred from small scales to larger scales, is found to extend into the submesoscale range, with a minimum scale of about 15 km.
DEEP-SEA RESEARCH PART II-TOPICAL STUDIES IN OCEANOGRAPHY
(2022)
Article
Oceanography
Haijin Cao, Zhiyou Jing
Summary: This study reveals the existence of strong submesoscale ageostrophic motions in the upper pycnocline of the Kuroshio Extension region through high-resolution simulations. These motions exhibit enhanced lateral buoyancy gradient and vigorous vertical velocity. The study further examines the mechanisms for the large vertical velocity and suggests that high-frequency, high-wavenumber processes dominate the vertical motions and significantly enhance the net vertical heat transport between the mixed layer and the ocean interior.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Oceanography
Zifei Chen, Fei Yu, Zhiwu Chen, Jianfeng Wang, Feng Nan, Qiang Ren, Yibo Hu, Anzhou Cao, Tongtong Zheng
Summary: This study investigates the interactions between near-inertial waves and a westward-moving anticyclonic eddy. It is found that near-inertial waves can propagate deep into the eddy and become trapped near the base of the eddy. The study also shows that the net energy transfer from the eddy to the near-inertial waves plays a crucial role in their propagation and deep-ocean mixing.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2023)
Article
Geosciences, Multidisciplinary
S. Sugimoto
Summary: The depth of the deep winter mixed layer in the northwestern North Pacific subtropical gyre has decreased by about 6% over the last six decades. The decrease in the mixed layer depth is attributed to the strengthening of ocean stratification due to global warming, and climate projections suggest further decreases in the future.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geography, Physical
Fang Qian, Fengming Chang, Tiegang Li, Anchun Li, Hanjie Sun, Junru Zhang
Summary: Thermocline conditions in the tropical western Pacific play a critical role in global climate evolution. However, the long-term changes in thermocline hydrology in the subtropical northwestern Pacific and its connection to the tropical Pacific are still unclear. Based on planktonic foraminiferal Mg/Ca and delta(18O), this study reconstructed the temperature and salinity of thermocline water in the subtropical northwestern Pacific since the last deglaciation. The results showed a close relationship between thermocline hydrology and changing conditions in the tropical western Pacific, indicating a significant role of the ENSO-like process in regulating thermocline dynamics.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2023)
Article
Oceanography
Zhiyou Jing, Baylor Fox-Kemper, Haijin Cao, Ruixi Zheng, Yan Du
Summary: Research has found active submesoscale density fronts in the northwest Pacific subtropical countercurrent system, with frontogenesis and symmetric instability processes playing important roles in shaping and enhancing these fronts.
JOURNAL OF PHYSICAL OCEANOGRAPHY
(2021)
Article
Multidisciplinary Sciences
Yong-Fu Lin, Chuen-Teyr Terng, Chau-Ron Wu, Jin-Yi Yu
Summary: This study identifies seasonally-reversed trends in Kuroshio strength and sea surface temperatures (SSTs) within the western North Pacific (WNP) since the 1990s, specifically in the 22°N-28°N region. The seasonally-reversed trends are a result of the asymmetric responses of the WNP to a shift towards the positive phase of the Atlantic multidecadal oscillation (AMO) around the same period. The associated responses of the East Asian monsoon and China Coastal Current contribute to the observed seasonally-reversed SST trends.
SCIENTIFIC REPORTS
(2023)
Article
Geosciences, Multidisciplinary
Xiao Liu, Jiyao Xu, Jia Yue, Masaru Kogure
Summary: This study investigates a unique type of gravity waves induced by the Tonga volcano eruption, using temperature profiles obtained from the Sounding of the Atmosphere using Broadband Emission Radiometry. The eruption was found to produce strong gravity waves in the mesosphere, with characteristics differing from those associated with other volcanic eruptions and extreme weather events.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
Jianmin Lin, Sunke Fang, Wen Xu, Sidao Ni, Han Zhang, Ting Yang
Summary: This study presents a comprehensive investigation of microseisms generated by typhoon Kalmaegi in 2014, revealing two different generation mechanisms. The findings are crucial for future tracking and monitoring of typhoons.
EARTH AND PLANETARY SCIENCE LETTERS
(2022)
Article
Environmental Sciences
Hui Zhou, William Dewar, Wenlong Yang, Hengchang Liu, Xu Chen, Rui Li, Chenglong Liu, Ganesh Gopalakrishnan
Summary: Symmetric instability is a mechanism that transfers geostrophic kinetic energy to overturning and dissipation, typically found at the ocean surface or near topographic boundary layers. Observational evidence from microstructure measurements in the northwestern equatorial Pacific thermocline shows enhanced dissipation caused by symmetric instability away from boundaries. The results suggest a new route to energy dissipation for large scale currents and a new ocean turbulent mixing process in the ocean interior.
COMMUNICATIONS EARTH & ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Xiao Liu, Jiyao Xu, Jia Yue, Masaru Kogure
Summary: The dissipation of gravity waves and the deposition of momentum flux significantly affect the atmospheric structure and circulation. Researchers have identified a persistent layer of enhanced gravity wave dissipation in the upper mesosphere, with possible mechanisms including wave refraction, wind filtering, and reduced static stability.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Ecology
Yun-Chi Lin, Chien-Pang Chin, Jinny Wu Yang, Kuo-Ping Chiang, Chih-hao Hsieh, Gwo-Ching Gong, Chi-Yu Shih, Szu-Ying Chen
Summary: This study used metabarcoding of 18S rDNA V4 region to reveal the spatial and temporal variations of Marine Stramenopiles (MASTs) in the southern East China Sea. It was found that MAST-9 had a high representation in warm waters, while MAST-1C was common in colder waters during spring. Canonical correspondence analysis showed that temperature, nitrite, and Synechococcus concentrations significantly influenced MASTs communities. Additionally, co-occurrence networks indicated that certain minor prokaryotic taxa could impact MAST communities.
Article
Environmental Sciences
Young Ho Ko, Geun-Ha Park, Dongseon Kim, Tae-Wook Kim
Summary: This study investigates the interannual variations in seawater CO2 partial pressure in the northwestern subtropical Pacific Ocean during the months of August to October with frequent tropical cyclone events. It found that the variations in pCO2 were related to vertical mixing likely caused by TC activity, leading the region to transition from a CO2 source to a CO2 sink during the TC season. In the southern part of the study area, smaller pCO2 variations were observed, possibly due to deeper mixed layer depth and a more homogenous CO2 profile in the tropical region.
FRONTIERS IN MARINE SCIENCE
(2021)
