scholarly journals The China Coastal Current as a driving force for transporting Calanus sinicus (Copepoda: Calanoida) from its population centers to waters off Taiwan and Hong Kong during the winter northeast monsoon period

2004 ◽  
Vol 27 (2) ◽  
pp. 205-210 ◽  
Author(s):  
J.-S. Hwang
Keyword(s):  
Hong Kong ◽  
Driving Force ◽  
Coastal Current ◽  
Northeast Monsoon ◽  
Calanus Sinicus ◽  
Monsoon Period ◽  
China Coastal Current

Effects of the China Coastal Current on the community structure of planktonic copepods in early spring, with notes on Eurytemora pacifica Sato, 1913 in the western Taiwan Strait

Crustaceana ◽  
2020 ◽  
Vol 93 (3-5) ◽  
pp. 487-506
Author(s):  
Yan-Guo Wang ◽  
Li-Chun Tseng ◽  
Rou-Xin Sun ◽  
Zhi-Yong Liu ◽  
Mao Lin ◽  
...  
Keyword(s):  
Community Structure ◽  
Research Area ◽  
Taiwan Strait ◽  
Early Spring ◽  
Average Density ◽  
Occurrence Rate ◽  
Coastal Current ◽  
Calanus Sinicus ◽  
China Coastal Current ◽  
The Taiwan Strait

Abstract The Taiwan Strait, located between Taiwan Island and the southeast of the mainland of China, is the main passageway connecting the East China Sea and the South China Sea. The particular coastline of the mainland created several semi-enclosed embayments along the west coast of the Taiwan Strait. Runoffs from land bring large amounts of nutrients into the bays, which made these bays important natural spawning and breeding grounds for several economically important marine organisms. In order to reveal the effects of the China Coastal Current (CCC) on the zooplankton communities in Fuqing Bay in northeastern Fujian, zooplankton samples were collected at 12 stations in early March 2014. The average surface seawater temperature was 12.53 ± 0.14°C, and salinity was 28.33 ± 0.21 PSU in the investigation area during the research period. In total, 23 identified copepod species and in addition several unidentified benthic harpacticoid copepods were recorded with an average abundance of 77.44 ± 60.07 ind. m−3. In the present study, the most dominant group consisted of juveniles (copepodites) with an average density of 59.97 ± 51.49 ind. m−3, which was followed by Calanus sinicus Brodsky, 1965 with an average density of 5.04 ± 4.95 ind. m−3. The occurrence rate of Calanus sinicus was 91.67% in our study, which indicates that the research area was controlled by the CCC water mass. So, we concluded that the CCC played an important role in transporting cold water copepod species from the Bohai Sea and the Yellow Sea to the western Taiwan Strait. A noteworthy discovery in our samples was Eurytemora pacifica Sato, 1913, which was recorded for the first time in waters of the western Taiwan Strait with an occurrence rate of 33.33% and an average density of 0.81 ± 1.91 ind. m−3. Eurytemora pacifica was first reported at Yantai harbour and is widely distributed in waters of the northern Pacific Ocean. The co-occurrence of Calanus sinicus and Eurytemora pacifica in our research area possibly indicates that E. pacifica could be used as a bioindicator for the directional movement of the CCC. The high occurrence of this species in our research area indicated that the CCC affects the community structure of copepods in the western Taiwan Strait in early spring.

scholarly journals Biophysical modelling of coastal upwelling variability and circulation along the Tanzanian and Kenyan coasts

2021 ◽  
pp. 43-61
Author(s):  
Issufo Halo ◽  
Philip Sagero ◽  
Majuto Manyilizu ◽  
Shigalla B. Mahongo
Keyword(s):  
Chlorophyll A ◽  
Ocean Circulation ◽  
Coastal Upwelling ◽  
Monsoon Season ◽  
Western Indian Ocean ◽  
Water Volume ◽  
Coastal Current ◽  
Spatial And Temporal Variability ◽  
Northeast Monsoon ◽  
Monsoon Period

Ocean circulation, upwelling phenomena and chlorophyll-a concentrations were investigated within the framework of numerical model simulations with 1/12° nested horizontal grid-size, in the tropical western Indian Ocean, along the coasts of Tanzania and Kenya. Ekman driven upwelling exhibited high levels of spatial and temporal variability in the region, characterized by a more vigorous occurrence/intensification during the Northeast than the Southwest Monsoon season. A similar trend was observed for chlorophyll-a distribution, but with an additional strong contribution during the inter-monsoon period from March to April. Trend analysis of a SST-derived coastal upwelling index (CUI) computed over the Pemba Channel and offshore of the East African Coastal Current (EACC), for 24 years (1990 - 2013), revealed a general linear relation of the form CUI(yr) = 2.4x10-7yr – 285, with a steady small annual increase of the upwelling phenomena by 0.0024/year ≃ 4% during the whole period of the simulation, which could be attributed to documented increasing trends of wind intensity and water volume transport in the region. The CUI exhibited the two most dominant peaks of variabilities on the range of annual and semi-annual timescales. The wind-stress southward component and the easting/westing veering of the northward EACC at 6°S revealed that these parameters were moderate and significantly correlated with the CUI (r = - 0.53 and 0.52, p<0.05) respectively, further suggesting its intensification during the Northeast Monsoon season.

scholarly journals ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

2016 ◽  
Vol 97 (10) ◽  
pp. 1859-1884 ◽  
Author(s):  
Hemantha W. Wijesekera ◽  
Emily Shroyer ◽  
Amit Tandon ◽  
M. Ravichandran ◽  
Debasis Sengupta ◽  
...  
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Indian Ocean ◽  
Bay Of Bengal ◽  
Regional Scale ◽  
Ocean Dynamics ◽  
Coastal Current ◽  
Northeast Monsoon ◽  
Low Salinity ◽  
Salinity Water

Abstract Air–Sea Interactions in the Northern Indian Ocean (ASIRI) is an international research effort (2013–17) aimed at understanding and quantifying coupled atmosphere–ocean dynamics of the Bay of Bengal (BoB) with relevance to Indian Ocean monsoons. Working collaboratively, more than 20 research institutions are acquiring field observations coupled with operational and high-resolution models to address scientific issues that have stymied the monsoon predictability. ASIRI combines new and mature observational technologies to resolve submesoscale to regional-scale currents and hydrophysical fields. These data reveal BoB’s sharp frontal features, submesoscale variability, low-salinity lenses and filaments, and shallow mixed layers, with relatively weak turbulent mixing. Observed physical features include energetic high-frequency internal waves in the southern BoB, energetic mesoscale and submesoscale features including an intrathermocline eddy in the central BoB, and a high-resolution view of the exchange along the periphery of Sri Lanka, which includes the 100-km-wide East India Coastal Current (EICC) carrying low-salinity water out of the BoB and an adjacent, broad northward flow (∼300 km wide) that carries high-salinity water into BoB during the northeast monsoon. Atmospheric boundary layer (ABL) observations during the decaying phase of the Madden–Julian oscillation (MJO) permit the study of multiscale atmospheric processes associated with non-MJO phenomena and their impacts on the marine boundary layer. Underway analyses that integrate observations and numerical simulations shed light on how air–sea interactions control the ABL and upper-ocean processes.

Diplosoma gumavirens (Ascidiacea, Didemnidae): the first record of photosymbiotic ascidians in the Taiwan Strait

2015 ◽  
Vol 8 ◽  
Author(s):  
Euichi Hirose ◽  
Mamiko Hirose ◽  
Jhy-Yun Shy
Keyword(s):  
Water Temperature ◽  
First Record ◽  
Taiwan Strait ◽  
Coastal Current ◽  
China Coastal Current ◽  
The Taiwan Strait ◽  
Penghu Islands

Diplosoma gumavirensspecimens were collected from the Penghu Islands, Taiwan. This is the first record of photosymbiotic ascidians in the Taiwan Strait, where the minimum water temperature in the winter is &lt;16°C because of intrusion of the China Coastal Current.

scholarly journals Relationship between Lightning Activity over Peninsular India and Sea Surface Temperature

2010 ◽  
Vol 49 (4) ◽  
pp. 828-835 ◽  
Author(s):  
M. I. R. Tinmaker ◽  
Kaushar Ali ◽  
G. Beig
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Monsoon Season ◽  
Lightning Activity ◽  
Sea Surface ◽  
Lightning Flash ◽  
Northeast Monsoon ◽  
Monsoon Period ◽  
Peninsular India ◽  
Seasonal Time Scale

Abstract This paper presents a study of spatiotemporal variation of lightning activity over Peninsular India (8°–22°N, 72°–88°E) by using monthly satellite-based lightning flash grid (1° × 1°) data for a period of 10 yr (1998–2007). The data are examined in terms of spatial, annual, and seasonal distribution of the lightning activity. It is found that lightning activity is higher over south Peninsular India and eastern India. On a seasonal time scale, the lightning activity shows two maxima—first in the month of May and then in the month of September. The lightning activity in the monsoon period is noticed to be considerable because of the occurrence of the low-level jet and increase in the monsoon break period. During the postmonsoon, the activity is mainly due to the presence of the convective nature of the disturbed weather during the northeast monsoon season over most parts of the east coast of south Peninsular India. The relationship between lightning activity over Peninsular India and sea surface temperature in the bordering seas (Arabian Sea and Bay of Bengal) is also examined. The results disclose a significant link between them.

Population abundance and body size of Calanus sinicus in marginal habitats in the coastal seas of south-eastern Hong Kong

2012 ◽  
Vol 93 (1) ◽  
pp. 135-142 ◽  
Author(s):  
G.-T. Zhang ◽  
C.K. Wong
Keyword(s):  
Hong Kong ◽  
Yellow Sea ◽  
Local Population ◽  
The Yellow Sea ◽  
Rapid Decline ◽  
The South ◽  
Calanus Sinicus ◽  
China Sea ◽  
The North ◽  
Chinese Coast

The species range of Calanus sinicus along the Chinese coast extends from the Bohai Sea and the Yellow Sea in the north to the northern part of the South China Sea in the south. The subtropical seas along the southern coast of China mark the southern edge of the range of C. sinicus. In coastal seas off eastern Hong Kong, C. sinicus appears first in December, but densities comparable to those in the Yellow Sea and the East China Sea are reached only in January and February when temperature is <15°C. Density decreases in March as temperature increases. No individuals remain after May when temperature is >25°C. The average prosome length of females collected in February is comparable to that of females from the Yellow Sea, but females collected after mid-March are smaller than the smallest females from the Yellow Sea. Reproduction occurred mainly between January and March. Rapid decline of the population in April and the absence of a summer population suggest that the local population is derived from individuals advected from the north by ocean currents. Eggs produced locally probably did not hatch or develop into adults.

Cross Flows in the Taiwan Strait in Winter*

2014 ◽  
Vol 44 (3) ◽  
pp. 801-817 ◽  
Author(s):  
L.-Y. Oey ◽  
Y.-L. Chang ◽  
Y.-C. Lin ◽  
M.-C. Chang ◽  
S. Varlamov ◽  
...  
Keyword(s):  
Cold Water ◽  
Numerical Models ◽  
Taiwan Strait ◽  
Finite Amplitude ◽  
Winter Monsoon ◽  
Coastal Current ◽  
Wind Regime ◽  
Calanus Sinicus ◽  
Northeasterly Wind ◽  
The Taiwan Strait

Abstract In winter, a branch of the China Coastal Current can turn in the Taiwan Strait to join the poleward-flowing Taiwan Coastal Current. The associated cross-strait flows have been inferred from hydrographic and satellite data, from observed abundances off northwestern Taiwan of cold-water copepod species Calanus sinicus and, in late March of 2012, also from debris found along the northwestern shore of Taiwan of a ship that broke two weeks earlier off the coast of China. The dynamics related to such cross flows have not been previously explained and are the focus of this study using analytical and numerical models. It is shown that the strait’s currents can be classified into three regimes depending on the strength of the winter monsoon: equatorward (poleward) for northeasterly winds stronger (weaker) than an upper (lower) bound and cross-strait flows for relaxing northeasterly winds between the two bounds. These regimes are related to the formation of the stationary Rossby wave over the Changyun Ridge off midwestern Taiwan. In the weak (strong) northeasterly wind regime, a weak (no) wave is produced. In the relaxing wind regime, cross-strait currents are triggered by an imbalance between the pressure gradient and wind and are amplified by the finite-amplitude meander downstream of the ridge where a strong cyclone develops.

Sign in / Sign up

Export Citation Format

Share Document