Estimation of interannual and interdecadal variations of typhoon-induced primary production: A case study for the outer shelf of the East China Sea

2007 ◽  
Vol 34 (3) ◽  
Author(s):  
Eko Siswanto ◽  
Joji Ishizaka ◽  
Katsumi Yokouchi ◽  
Katsuhisa Tanaka ◽  
Chun Knee Tan
Keyword(s):  
Primary Production ◽  
East China Sea ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
China Sea

scholarly journals Responses of lower trophic-level organisms to typhoon passage on the outer shelf of the East China Sea: an incubation experiment

2013 ◽  
Vol 10 (4) ◽  
pp. 6605-6635 ◽  
Author(s):  
N. Yasuki ◽  
K. Suzuki ◽  
A. Tsuda
Keyword(s):  
Water Column ◽  
East China Sea ◽  
Trophic Level ◽  
Outer Shelf ◽  
East China ◽  
Strong Wind ◽  
The East China Sea ◽  
Phytoplankton Productivity ◽  
China Sea ◽  
Lower Trophic Level

Abstract. Typhoons can induce vertical mixing, upwelling, or both in the water column due to strong wind stress. These events can induce phytoplankton blooms in the oligotrophic ocean after typhoon passage. However, little is known about the responses of lower trophic-level organisms or changes in the community structure following the passage of typhoons, particularly in offshore regions. Therefore, we evaluated community succession on the outer shelf of the East China Sea through on-deck bottle incubation experiments simulating hydrographic conditions after the passage of a typhoon. Under all of the experimental conditions we tested, chlorophyll a concentrations increased more than 9-fold within 6 days, and these algal cells were mainly composed of large diatoms (>10 μm). Ciliates also increased along with the diatom bloom. These results suggest that increases in diatom and ciliate populations may enhance biogenic carbon export in the water column. Typhoons can affect not only phytoplankton productivity, but also the composition of lower trophic-level organisms and biogeochemical processes in oligotrophic offshore regions.

scholarly journals Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

2016 ◽  
Vol 38 (1-2) ◽  
pp. 187-198 ◽  
Author(s):  
Ziyin Wu ◽  
Xianglong Jin ◽  
Jieqiong Zhou ◽  
Dineng Zhao ◽  
Jihong Shang ◽  
...  
Keyword(s):  
East China Sea ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Sand Ridges

Characteristics of outer shelf water in the East China Sea

2013 ◽  
Vol 69 (2) ◽  
pp. 245-258 ◽  
Author(s):  
Shigefumi Yanao ◽  
Takeshi Matsuno
Keyword(s):  
East China Sea ◽  
Outer Shelf ◽  
East China ◽  
Shelf Water ◽  
The East China Sea ◽  
China Sea

Looming hypoxia on outer shelves caused by reduced ventilation in the open oceans: Case study of the East China Sea

2014 ◽  
Vol 151 ◽  
pp. 355-360 ◽  
Author(s):  
Hon-Kit Lui ◽  
Chen-Tung Arthur Chen ◽  
Jay Lee ◽  
Yan Bai ◽  
Xianqiang He
Keyword(s):  
East China Sea ◽  
East China ◽  
The East China Sea ◽  
China Sea

scholarly journals Influence of cross-shelf water transport on nutrients and phytoplankton in the East China Sea: a model study

2010 ◽  
Vol 7 (4) ◽  
pp. 1405-1437
Author(s):  
L. Zhao ◽  
X. Guo
Keyword(s):  
Surface Layer ◽  
Primary Production ◽  
Chlorophyll A ◽  
East China Sea ◽  
Changjiang Estuary ◽  
Shelf Break ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
Inner Shelf

Abstract. A three dimensional coupled biophysical model was used to examine the supply of oceanic nutrients to the shelf of the East China Sea (ECS) and its role in primary production over the shelf. The model consisted of two modules: the hydrodynamic module was based on a nested model with a horizontal resolution of 1/18 degree, whereas the biological module was a low trophic level ecosystem model including two types of phytoplankton, three elements of nutrients, and biogenic organic material. Model results suggested that seasonal variation in chlorophyll-a had a strong regional dependence over the shelf of the ECS. The area with high chlorophyll-a appears firstly at the outer shelf in winter, and gradually migrates toward the inner shelf (offshore region of Changjiang estuary) from spring to summer. Vertically, chlorophyll-a was generally homogenous from the coastal zone to the inner shelf. In the middle and outer shelves, high chlorophyll-a appeared in the surface in spring but moved to the subsurface from summer to early autumn. The annual averaged onshore flux across the shelf break was estimated to be 1.53 Sv for volume, 9.4 kmol s−1 for DIN, 0.7 kmol s−1 for DIP, and 18.2 kmol s−1 for silicate, which are supplied mainly from the northeast of Taiwan and southwest of Kyushu. From calculations that artificially increased the concentration of nutrients in the Kuroshio water, the additional oceanic nutrients were distributed in the bottom layer from the shelf break to the region offshore of Changjiang estuary from spring to summer, and appeared in the surface layer from autumn to winter. The contribution of oceanic nutrients to primary production over the shelf was found not only in the surface layer (mainly at the outer shelf and shelf break in winter and in the region offshore of Changjiang estuary in summer) but also in the subsurface layer over the shelf from spring to autumn.

scholarly journals Anaerobic ammonium oxidation, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment

2013 ◽  
Vol 10 (3) ◽  
pp. 4671-4710 ◽  
Author(s):  
G. D. Song ◽  
S. M. Liu ◽  
H. Marchant ◽  
M. M. M. Kuypers ◽  
G. Lavik
Keyword(s):  
East China Sea ◽  
Nitrate Reduction ◽  
Nitrogen Transformation ◽  
Outer Shelf ◽  
East China ◽  
The East China Sea ◽  
N Loss ◽  
High Background ◽  
China Sea ◽  
Dissimilatory Nitrate Reduction

Abstract. Benthic nitrogen transformation pathways were investigated in the sediment of the East China Sea in June of 2010 using the 15N isotope pairing technique. Slurry incubations indicated that denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA) as well as nitrate release by nitrate storing organisms occurred in the East China Sea sediments. These four processes did not exist independently, the nitrate release therefore diluted the 15N labeling fraction of NO3−, a part of the 15NH4+ derived from DNRA also formed 30N2 via anammox. Therefore current methods of rate calculations led to over and underestimations of anammox and denitrification respectively. Following the procedure outlined in Thampdrup and Dalsgaard (2002), denitrification rates were slightly underestimated by on average 6% without regard to the effect of nitrate release, while this underestimation could be counteracted by the presence of DNRA. On the contrary, anammox rates calculated from 15NO3− experiment were significantly overestimated by 42% without considering nitrate release. In our study this overestimation could only be compensated 14% by taking DNRA into consideration. In a parallel experiment amended with 15NH4+ + 14NO3−, anammox rates were not significantly influenced by DNRA due to the high background of 15NH4+ addition. Excluding measurements in which bioirrigation was present, integrated denitrification rates decreased from 10 to 4 mmol N m−2 d−1 with water depth, while integrated anammox rates increased from 1.5 to 4.0 mmol N m−2 d−1. Consequently, the relative contribution of anammox to the total N-loss increased from 13% at the shallowest site near the Changjiang estuary to 50% at the deepest site on the outer shelf. This study represents the first time in which anammox has been demonstrated to play a significant role in benthic nitrogen cycling in the East China Sea sediment, especially on the outer shelf. N-loss as N2 was the main pathway, while DNRA was also an important pathway accounting for 20–31% of benthic nitrogen transformation in the East China Sea. Our study demonstrates the complicated interactions among different benthic nitrogen transformations and the importance of considering denitrification, DNRA, anammox and nitrate release together when designing and interpreting future studies.

scholarly journals Impacts of climate change and emissions on atmospheric oxidized nitrogen deposition over East Asia

2019 ◽  
Vol 19 (2) ◽  
pp. 887-900 ◽  
Author(s):  
Junxi Zhang ◽  
Yang Gao ◽  
L. Ruby Leung ◽  
Kun Luo ◽  
Huan Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
Primary Production ◽  
East China Sea ◽  
East China ◽  
Anthropogenic Emissions ◽  
The East China Sea ◽  
Ship Emissions ◽  
China Sea ◽  
Emission Changes ◽  
Marine Primary Production

Abstract. A multi-model ensemble of Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) simulations is used to study the atmospheric oxidized nitrogen (NOy) deposition over East Asia under climate and emission changes projected for the future. Both dry and wet NOy deposition show significant decreases in the 2100s under RCP4.5 and RCP8.5, primarily due to large anthropogenic emission reduction over both land and sea. However, in the near future of the 2030s, both dry and wet NOy deposition increase significantly due to continued increase in emissions. Marine primary production from both dry and wet NOy deposition increases by 19 %–34 % in the 2030s and decreases by 34 %–63 % in the 2100s over the East China Sea. The individual effect of climate or emission changes on dry and wet NOy deposition is also investigated. The impact of climate change on dry NOy deposition is relatively minor, but the effect on wet deposition, primarily caused by changes in precipitation, is much higher. For example, over the East China Sea, wet NOy deposition increases significantly in summer due to climate change by the end of this century under RCP8.5, which may subsequently enhance marine primary production. Over the coastal seas of China, as the transport of NOy from land becomes weaker due to the decrease in anthropogenic emissions, the effect of ship emissions and lightning emissions becomes more important. On average, the seasonal mean contribution of ship emissions to total NOy deposition is projected to be enhanced by 24 %–48 % and 3 %–37 % over the Yellow Sea and East China Sea, respectively, by the end of this century. Therefore, continued control of both anthropogenic emissions over land and ship emissions may reduce NOy deposition to the Chinese coastal seas.

Influence of shallow gas on the geotechnical properties of pockmark soil: A case study in the East China Sea

2019 ◽  
Vol 93 ◽  
pp. 101966
Author(s):  
Hongyue Sun ◽  
Zhongxuan Chen ◽  
Xianghua Lai ◽  
Xin Yan ◽  
Taojun Hu
Keyword(s):  
East China Sea ◽  
Geotechnical Properties ◽  
East China ◽  
The East China Sea ◽  
Shallow Gas ◽  
China Sea
Sign in / Sign up

Export Citation Format

Share Document