scholarly journals Intraseasonal Variability of the Kuroshio at 18°N Observed by Mooring Array in 2018-2020

2021 ◽  
Author(s):  
Xin Yuan ◽  
Qingye Wang ◽  
Jie Ma ◽  
Shijian Hu ◽  
Dunxin Hu
Keyword(s):  
Current Velocity ◽  
Intraseasonal Variability ◽  
Propagation Speed ◽  
Kuroshio Current ◽  
Volume Transport ◽  
Direct Measurements ◽  
First Time ◽  
The Kuroshio ◽  
Kuroshio Transport

Abstract Based on direct measurements of the Kuroshio current velocity at 18°N by an array of three moorings from January 2018 to February 2020, the intraseasonal variability (ISV) of the Kuroshio and possible dynamic mechanism are studied. The Kuroshio transport in the upper 350m between 122.7°E and 123.3°E is estimated to be 6.5 Sv ± 2.6 Sv. It is revealed for the first time that both the current velocity and volume transport the Kuroshio at 18°N have a significant 50-60-day ISV, which contributes to over 30% of the total variance. Further analysis indicates the ISV of the Kuroshio is caused by the westward propagating eddies with a wavelength of about 633 km and a propagation speed of about 13 cm/s. In addition, the transport mode (74.2%) of the Kuroshio at 18°N is dominant, rather than the migration mode (11.6%). That is different from the Kuroshio east of Taiwan. The findings of this study will highlight the important role of westward Rossby waves (eddies) with a finite wavelength in modulating the intraseasonal variability of the Kuroshio transport near its origin.

scholarly journals Combining Observations from Multiple Platforms across the Kuroshio Northeast of Luzon: A Highlight on PIES Data

2016 ◽  
Vol 33 (10) ◽  
pp. 2185-2203 ◽  
Author(s):  
Vigan Mensah ◽  
Magdalena Andres ◽  
Ren-Chieh Lien ◽  
Barry Ma ◽  
Craig M. Lee ◽  
...  
Keyword(s):  
Time Series ◽  
Current Velocity ◽  
Mean Field ◽  
Volume Transport ◽  
Velocity Shear ◽  
Western Boundary ◽  
Thermocline Depth ◽  
Boundary Current ◽  
Processing Scheme ◽  
The Kuroshio

AbstractThis study presents amended procedures to process and map data collected by pressure-sensor-equipped inverted echo sounders (PIESs) in western boundary current regions. The modifications to the existing methodology, applied to observations of the Kuroshio from a PIES array deployed northeast of Luzon, Philippines, consist of substituting a hydrography-based mean travel time field for the PIES-based mean field and using two distinct gravest empirical mode (GEM) lookup tables across the front that separate water masses of South China Sea and North Pacific origin. In addition, this study presents a method to use time-mean velocities from acoustic Doppler current profilers (ADCPs) to reference (or “level”) the PIES-recorded pressures in order to obtain time series of absolute geostrophic velocity. Results derived from the PIES observations processed with the hydrography-based mean field and two GEMs are compared with hydrographic profiles sampled by Seagliders during the PIES observation period and with current velocity measured concurrently by a collocated ADCP array. The updated processing scheme leads to a 41% error decrease in the determination of the thermocline depth across the current, a 22% error decrease in baroclinic current velocity shear, and a 61% error decrease in baroclinic volume transports. The absolute volume transport time series derived from the leveled PIES array compares well with that obtained directly from the ADCPs with a root-mean-square difference of 3.0 Sv (1 Sv ≡ 106 m3 s–1), which is mainly attributed to the influence of ageostrophic processes on the ADCP-measured velocities that cannot be calculated from the PIES observations.

scholarly journals Internal Tides and Their Intraseasonal Variability on the Continental Slope Northeast of Taiwan Island Derived from Mooring Observations and Satellite Data

2021 ◽  
Vol 14 (1) ◽  
pp. 59
Author(s):  
Yuqi Yin ◽  
Ze Liu ◽  
Yuanzhi Zhang ◽  
Qinqin Chu ◽  
Xihui Liu ◽  
...  
Keyword(s):  
Continental Slope ◽  
Satellite Data ◽  
Bottom Topography ◽  
Intraseasonal Variability ◽  
Mesoscale Eddies ◽  
Kuroshio Current ◽  
Internal Tides ◽  
Taiwan Island ◽  
The Impact ◽  
The Kuroshio

In this study, strong internal tides were observed on the continental slope northeast of Taiwan Island. Owing to the lack of long-term observations, these tides’ intraseasonal variability and the impact of the Kuroshio Current remain unclear. This study aimed to fill in the gaps using one-year continuous mooring observations, satellite data and analysis data. The horizontal kinetic energy (HKE) of semidiurnal internal tides showed that there was conspicuous energy from 100 days to 200 days, which was mainly attributed to the cross-term of HKE. The impact of the Kuroshio Current and mesoscale eddies on the HKEs were assessed: Cyclonic (anticyclonic) mesoscale eddies propagated from the open ocean, weakened (strengthened) the Kuroshio and shifted the Kuroshio onshore (offshore) northeast of Taiwan Island. The weakened (strengthened) Kuroshio increased (decreased) the shoreward velocity at the mooring site, and the onshore (offshore) Kuroshio migration increased (decreased) the northeastward velocity and enhanced (weakened) the HKEs of internal tides by modulating the tidal energy horizontal propagation. The weakened (strengthened) Kuroshio also resulted in gentler (steeper) isopycnals across the slope and enhanced (weakened) the HKEs of internal tides by influencing the interaction between ocean stratification and bottom topography.

scholarly journals Phytoplankton and Bacterial Responses to Monsoon-Driven Water Masses Mixing in the Kuroshio Off the East Coast of Taiwan

2021 ◽  
Vol 8 ◽  
Author(s):  
Chao-Chen Lai ◽  
Chau-Ron Wu ◽  
Chia-Ying Chuang ◽  
Jen-Hua Tai ◽  
Kuo-Yuan Lee ◽  
...  
Keyword(s):  
East Coast ◽  
Three Dimensional ◽  
Euphotic Zone ◽  
Kuroshio Current ◽  
Southwest Monsoon ◽  
Three Dimensional Model ◽  
Southern Taiwan ◽  
First Time ◽  
The Kuroshio ◽  
Mixing Water

Biogeochemical responses to mixing were examined in two cruise surveys along a transect across the Kuroshio Current (KC) in May and July 2020. Two stations located at the South China Sea (SCS)–KC mixing and the KC waters were chosen for the diel study. In the euphotic zone (~100 m depth), the average values of nitrate (0.97–1.62 μM), chlorophyll-a (Chl-a, 0.36–0.40 mg/m3), and primary production (PP; 3.46 ± 1.37 mgC/m3/day) of the mixing water station (MWS) of the two cruises were several folds higher than those of the KC station (KCS; nitrate, 0.03–0.10 μM; Chl-a, 0.14–0.24 mg/m3; and PP, 0.91 ± 0.47 mgC/m3/day). In the July cruise, the maximal bacterial production (BP) at the MWS (3.31 mgC/m3/day) was 82% higher in comparison with that of the KCS (1.82 mgC/m3/day); and the readings of Chl-a showed no trend with BP in the oligotrophic KCS, but a positive relationship was found among these measurements at the mesotrophic MWS. This implies that the trophic status of the system might affect phytoplankton–bacteria interactions. The backward-trajectory analyses conducted by an observation-validated three-dimensional model identified that the prevailing southwest monsoon drove a northeastward “intrusion” of the SCS waters in July 2020, resulted in mixing between SCS and Kuroshio (KC) waters off the east coast of southern Taiwan. For the first time, this study demonstrates that the high biological biomass and activities that occur in the KC are induced by the northward intrusion of the SCS waters.

scholarly journals Key Role of the Kuroshio Current in the Formation of Frontal Structure of an Extratropical Cyclone Associated with Heavy Precipitation

2019 ◽  
Vol 124 (12) ◽  
pp. 6143-6156 ◽  
Author(s):  
Hidetaka Hirata ◽  
Ryuichi Kawamura ◽  
Mayumi K. Yoshioka ◽  
Masami Nonaka ◽  
Kazuhisa Tsuboki
Keyword(s):  
Heavy Precipitation ◽  
Kuroshio Current ◽  
Extratropical Cyclone ◽  
Frontal Structure ◽  
The Kuroshio

scholarly journals Zooplankton Fluctuations in the Surface Waters of the Estuary of a Large Subtropical Urban River

2021 ◽  
Vol 9 ◽  
Author(s):  
Pei-Wen Lee ◽  
Shih-Hui Hsiao ◽  
Chi Chou ◽  
Li-Chun Tseng ◽  
Jiang-Shiou Hwang
Keyword(s):  
Catchment Area ◽  
Seasonal Succession ◽  
Kuroshio Current ◽  
Coastal Current ◽  
Similar Data ◽  
Physico Chemical ◽  
Variable Chemical ◽  
Parvocalanus Crassirostris ◽  
First Time ◽  
The Kuroshio

The Danshuei River has a third largest catchment area and third longest in Taiwan. It flows through the capital, Taipei, and more than six million people live within its catchment area. Its estuary is characterized by a highly variable chemical and physical environment that is affected by the interaction of inland freshwater runoff with wastewater, and toward the coast is also influenced by the China Coastal Current and the Kuroshio Current. By collecting zooplankton bimonthly in 2014 from the surface layer (0–2 m depth) at five sites in the estuary, we were able to demonstrate that the composition of the zooplankton, and particularly its copepod fraction, varied significantly among sampling stations and months, thereby revealing seasonal succession. Fourteen higher taxa or other categories of zooplankter were identified, with the following being most common taxa: Decapoda, Copepoda (including Calanoida, Cyclopoida, and Harpacticoida), and “other larvae.” The Copepoda comprised 44 taxa (including eight only identified to genus) belonging to 3 orders, 17 families, and 29 genera, the five most abundant of which were Bestiolina n. sp. (undescribed), Corycaeus spp., Parvocalanus crassirostris, Acartia sp., and Paracalanus parvus. The highest and lowest copepod abundances were recorded in July (2557.88 inds. m–3) and January (1.3 inds. m–3), respectively. Observed changes in abundance of many kinds of copepod appeared to be significantly related to changes in physico-chemical parameters (e.g., salinity, temperature, pH, and dissolved oxygen concentration). Cluster analysis confirmed the existence of distinct copepod communities, each characterized by a preference for a different set of environmental conditions. Our comprehensive literature review of the copepod biodiversity of Taiwan’s major rivers for comparison with similar data compiled for other estuaries in the world, the first time such a review has been compiled, shows that 32 copepod taxa have been recorded from the brackish and freshwater parts of the Danshuei River. They represent 58.2% of the total number of brackish- and freshwater copepod species in Taiwan, and five of them have so far only been recorded in the Danshuei River: the calanoids Acartiella sinensis and Pseudodiaptomus forbesi, the cyclopoids Oithona fragilis and Oithona simplex, and the harpacticoid Tachidius (Tachidius) discipes.

Psychological Resilience Provides No Independent Protection From Suicidal Risk

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 130-139 ◽  
Author(s):  
Danica W. Y. Liu ◽  
A. Kate Fairweather-Schmidt ◽  
Richard Burns ◽  
Rachel M. Roberts ◽  
Kaarin J. Anstey
Keyword(s):  
Risk Factors ◽  
Well Being ◽  
Current Status ◽  
Psychological Resilience ◽  
Cross Sectional ◽  
Life Project ◽  
Resilience Factors ◽  
First Time

Abstract. Background: Little is known about the role of resilience in the likelihood of suicidal ideation (SI) over time. Aims: We examined the association between resilience and SI in a young-adult cohort over 4 years. Our objectives were to determine whether resilience was associated with SI at follow-up or, conversely, whether SI was associated with lowered resilience at follow-up. Method: Participants were selected from the Personality and Total Health (PATH) Through Life Project from Canberra and Queanbeyan, Australia, aged 28–32 years at the first time point and 32–36 at the second. Multinomial, linear, and binary regression analyses explored the association between resilience and SI over two time points. Models were adjusted for suicidality risk factors. Results: While unadjusted analyses identified associations between resilience and SI, these effects were fully explained by the inclusion of other suicidality risk factors. Conclusion: Despite strong cross-sectional associations, resilience and SI appear to be unrelated in a longitudinal context, once risk/resilience factors are controlled for. As independent indicators of psychological well-being, suicidality and resilience are essential if current status is to be captured. However, the addition of other factors (e.g., support, mastery) makes this association tenuous. Consequently, resilience per se may not be protective of SI.

Synergetic Theory of Document in Evolution of Document Science

2018 ◽  
pp. 1060-1068
Author(s):  
Galina A. Dvoenosova ◽  
Keyword(s):  
Social Role ◽  
Scientific Study ◽  
Self Organization ◽  
Universal Theory ◽  
Social Self ◽  
Social Goal ◽  
The Social ◽  
Synergetic Theory ◽  
First Time

The article assesses synergetic theory of document as a new development in document science. In information society the social role of document grows, as information involves all members of society in the process of documentation. The transformation of document under the influence of modern information technologies increases its interest to representatives of different sciences. Interdisciplinary nature of document as an object of research leads to an ambiguous interpretation of its nature and social role. The article expresses and contends the author's views on this issue. In her opinion, social role of document is incidental to its being a main social tool regulating the life of civilized society. Thus, the study aims to create a scientific theory of document, explaining its nature and social role as a tool of social (goal-oriented) action and social self-organization. Substantiation of this idea is based on application of synergetics (i.e., universal theory of self-organization) to scientific study of document. In the synergetic paradigm, social and historical development is seen as the change of phases of chaos and order, and document is considered a main tool that regulates social relations. Unlike other theories of document, synergetic theory studies document not as a carrier and means of information transfer, but as a unique social phenomenon and universal social tool. For the first time, the study of document steps out of traditional frameworks of office, archive, and library. The document is placed on the scales with society as a global social system with its functional subsystems of politics, economy, culture, and personality. For the first time, the methods of social sciences and modern sociological theories are applied to scientific study of document. This methodology provided a basis for theoretical vindication of nature and social role of document as a tool of social (goal-oriented) action and social self-organization. The study frames a synergetic theory of document with methodological foundations and basic concepts, synergetic model of document, laws of development and effectiveness of document in the social continuum. At the present stage of development of science, it can be considered the highest form of theoretical knowledge of document and its scientific explanatory theory.

Physical Warmth Attenuates Ethnocentric Bias under Mortality Salience: An Embodied Terror Management Perspective

2020 ◽  
Author(s):  
Armand Chatard ◽  
Margaux Renoux ◽  
Jean Monéger ◽  
Leila Selimbegovic
Keyword(s):  
Mortality Salience ◽  
Terror Management ◽  
Negative Consequences ◽  
Defensive Reaction ◽  
Worldview Defense ◽  
Management Perspective ◽  
Physical Warmth ◽  
Alternative Means ◽  
First Time

Research indicates that individuals often deal with mortality salience by affirming beliefs in national or cultural superiority (worldview defense). Because worldview defense may be associated with negative consequences (discrimination), it is important to identify alternative means to deal with death-related thoughts. In line with an embodied terror management perspective, we evaluate for the first time the role of physical warmth in reducing defensive reaction to mortality salience. We predicted that, like social affiliation (social warmth), physical warmth could reduce worldview defense when mortality is salient. In this exploratory (preregistered) study, 202 French participants were primed with death-related thoughts, or an aversive control topic, in a heated room or a non-heated room. The main outcome was worldview defense (ethnocentric bias). We found no main effect of mortality salience on worldview defense. However, physical warmth reduced worldview defense when mortality was salient. Implications for an embodied terror management perspective are discussed.

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