scholarly journals Seasonal Variability and Future Projection of Ocean Acidification on the East China Sea Shelf off the Changjiang Estuary

2021 ◽  
Vol 8 ◽  
Author(s):  
Xianghui Guo ◽  
Zhentong Yao ◽  
Ying Gao ◽  
Yaohua Luo ◽  
Yi Xu ◽  
...  
Keyword(s):  
Surface Water ◽  
Ocean Acidification ◽  
East China Sea ◽  
Bottom Water ◽  
Changjiang Estuary ◽  
The Yellow Sea ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea

Ocean acidification (OA) occurs universally in the world’s oceans. Marginal seas are facing more serious OA than the open ocean due to strong anthropogenic and natural impacts. This study investigates carbonate dynamics on the East China Sea (ECS) shelf off the Changjiang Estuary using field observations made from 2015 to 2019 that cover all four seasons. In the low productivity cold seasons, the water was well-mixed vertically. The coastal area and the northern ECS were occupied by water characterized by high dissolved inorganic carbon (DIC), low pH25 (pH at 25°C), and low ΩAr (saturation state index of aragonite), and influenced by the coastal water from the Yellow Sea (YS). However, during highly productive warm seasons, pH25 and ΩAr increased in the surface water but decreased in the bottom water as a result of strong biological DIC uptake in the surface water and CO2 production by strong organic matter remineralization in the bottom water. Strong remineralization decreased pH25 and ΩAr by 0.18 ± 0.08 and 0.73 ± 0.35 in the hypoxic bottom water in summer, even though the bottom water remained oversaturated with respect to aragonite (ΩAr > 1.0) during the surveys. Under the context of global OA and the strong seasonal acidification, the projected bottom water on the ECS shelf will be corrosive for aragonite by mid-century.

scholarly journals Air–sea CO<sub>2</sub> fluxes in the East China Sea based on multiple-year underway observations

2015 ◽  
Vol 12 (18) ◽  
pp. 5495-5514 ◽  
Author(s):  
X.-H. Guo ◽  
W.-D. Zhai ◽  
M.-H. Dai ◽  
C. Zhang ◽  
Y. Bai ◽  
...  
Keyword(s):  
East China Sea ◽  
Co2 Flux ◽  
Changjiang Estuary ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
Data Set ◽  
China Sea ◽  
Fujian Coast ◽  
Partial Pressure Of Co2

Abstract. This study reports the most comprehensive data set thus far of surface seawater pCO2 (partial pressure of CO2) and the associated air–sea CO2 fluxes in a major ocean margin, the East China Sea (ECS), based on 24 surveys conducted in 2006 to 2011. We showed highly dynamic spatial variability in sea surface pCO2 in the ECS except in winter, when it ranged across a narrow band of 330 to 360 μatm. We categorized the ECS into five different domains featuring with different physics and biogeochemistry to better characterize the seasonality of the pCO2 dynamics and to better constrain the CO2 flux. The five domains are (I) the outer Changjiang estuary and Changjiang plume, (II) the Zhejiang–Fujian coast, (III) the northern ECS shelf, (IV) the middle ECS shelf, and (V) the southern ECS shelf. In spring and summer, pCO2 off the Changjiang estuary was as low as < 100 μatm, while it was up to > 400 μatm in autumn. pCO2 along the Zhejiang–Fujian coast was low in spring, summer and winter (300 to 350 μatm) but was relatively high in autumn (> 350 μatm). On the northern ECS shelf, pCO2 in summer and autumn was > 340 μatm in most areas, higher than in winter and spring. On the middle and southern ECS shelf, pCO2 in summer ranged from 380 to 400 μatm, which was higher than in other seasons (< 350 μatm). The area-weighted CO2 flux on the entire ECS shelf was −10.0 ± 2.0 in winter, −11.7 ± 3.6 in spring, −3.5 ± 4.6 in summer and −2.3 ± 3.1 mmol m−2 d−1 in autumn. It is important to note that the standard deviations in these flux ranges mostly reflect the spatial variation in pCO2 rather than the bulk uncertainty. Nevertheless, on an annual basis, the average CO2 influx into the entire ECS shelf was 6.9 ± 4.0 mmol m−2 d−1, about twice the global average in ocean margins.

Eutrophication-Driven Hypoxia in the East China Sea off the Changjiang Estuary

2016 ◽  
Vol 50 (5) ◽  
pp. 2255-2263 ◽  
Author(s):  
Hongjie Wang ◽  
Minhan Dai ◽  
Jinwen Liu ◽  
Shuh-Ji Kao ◽  
Chao Zhang ◽  
...  
Keyword(s):  
East China Sea ◽  
Changjiang Estuary ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea

scholarly journals Biogeochemistry of Dimethylsulfide, Dimethylsulfoniopropionate, and Acrylic Acid in the Changjiang Estuary and the East China Sea

2017 ◽  
Vol 122 (12) ◽  
pp. 10245-10261 ◽  
Author(s):  
Xi Wu ◽  
Pei‐Feng Li ◽  
Chun‐Ying Liu ◽  
Hong‐Hai Zhang ◽  
Gui‐Peng Yang ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
East China Sea ◽  
Changjiang Estuary ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea

scholarly journals Bacterial diversity in the surface sediments of the hypoxic zone near the Changjiang Estuary and in the East China Sea

2016 ◽  
Vol 5 (2) ◽  
pp. 323-339 ◽  
Author(s):  
Qi Ye ◽  
Ying Wu ◽  
Zhuoyi Zhu ◽  
Xiaona Wang ◽  
Zhongqiao Li ◽  
...  
Keyword(s):  
Bacterial Diversity ◽  
East China Sea ◽  
Surface Sediments ◽  
Changjiang Estuary ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea ◽  
Hypoxic Zone

scholarly journals Methane distribution, flux, and budget in the East China Sea and Yellow Sea

2015 ◽  
Vol 12 (9) ◽  
pp. 7017-7053 ◽  
Author(s):  
M.-S. Sun ◽  
G.-L. Zhang ◽  
X.-P. Cao ◽  
X.-Y. Mao ◽  
J. Li ◽  
...  
Keyword(s):  
East China Sea ◽  
Yellow Sea ◽  
The Yellow Sea ◽  
East China ◽  
Hangzhou Bay ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea ◽  
Ch4 Production ◽  
Ch4 Concentration

Abstract. We measured dissolved methane (CH4) concentrations, saturations, and fluxes from sea into air and from sediment into water during cruises in March, May, August, October, and December of 2011 in the East China Sea (ECS) and the Yellow Sea (YS). CH4 concentrations had obvious spatial and seasonal variability due to the complex effects of different water masses and other variables. Maximal CH4 concentration, sea–air and sediment–water fluxes all occurred during the summer. CH4 concentration decreased gradually from the coastal area to the open sea, and high levels of CH4 generally appeared near the Changjiang Estuary and outside the Hangzhou Bay. During early spring and winter, CH4 had a uniform distribution from the surface to the bottom, but CH4 concentration increased gradually with depth during other seasons. The subsurface CH4 maximum occurred at a depth of about 200 m during May, October, and December. The CH4 level at the bottom was generally higher than at the surface, and this was enhanced during summer due to hypoxia in the bottom waters. Changjiang-diluted water, the Kuroshio Current, and the Taiwan Warm Current Water affected the geographic distribution of CH4 in the ECS, and these water bodies contributed about 3.45, 2.97, 14.60 mol s−1 of CH4 during summer and 2.11, 8.58, 5.20 mol s−1 CH4 during winter, respectively. Sediment was also a significant source of dissolved CH4 in the ECS, and we estimated the average sediment–water CH4 flux of the ECS and YS as about 1.02 μmol m−2 d−1. We also used a box model to calculate the CH4 budget in the ECS. The results suggested that in situ CH4 production in the water column was the major source of CH4, and accounted for 0.21 μmol m−3 day−1 during summer and 0.11 μmol m−3 day−1 during winter. Air–sea exchange was the major sink of CH4 in the ECS. We estimated total CH4 emission from the ECS and YS as about 4.45 x 109 mol during 2011. Our results indicated that the ECS and YS were active areas for CH4 production and emission.

Non-local drivers of the summer hypoxia in the East China Sea off the Changjiang Estuary

2017 ◽  
Vol 198 ◽  
pp. 393-399 ◽  
Author(s):  
Wei Qian ◽  
Minhan Dai ◽  
Min Xu ◽  
Shuh-ji Kao ◽  
Chuanjun Du ◽  
...  
Keyword(s):  
East China Sea ◽  
Changjiang Estuary ◽  
East China ◽  
The East China Sea ◽  
The Changjiang Estuary ◽  
China Sea ◽  
Non Local
Sign in / Sign up

Export Citation Format

Share Document