scholarly journals Sea surface salinity changes in the East China Sea during 1997-2001: Influence of the Yangtze River

2002 ◽  
Vol 107 (C12) ◽  
pp. SRF 9-1-SRF 9-11 ◽  
Author(s):  
Thierry Delcroix ◽  
Raghuram Murtugudde
2020 ◽  
Vol 12 (5) ◽  
pp. 755
Author(s):  
Dae-Won Kim ◽  
Young-Je Park ◽  
Jin-Yong Jeong ◽  
Young-Heon Jo

Sea surface salinity (SSS) is an important tracer for monitoring the Changjiang Diluted Water (CDW) extension into Korean coastal regions; however, observing the SSS distribution in near real time is a difficult task. In this study, SSS detection algorithm was developed based on the ocean color measurements by Geostationary Ocean Color Imager (GOCI) in high spatial and temporal resolution using multilayer perceptron neural network (MPNN). Among the various combinations of input parameters, combinations with three to six bands of GOCI remote sensing reflectance (Rrs), sea surface temperature (SST), longitude, and latitude were most appropriate for estimating the SSS. According to model validations with the Soil Moisture Active Passive (SMAP) and Ieodo Ocean Research Station (I-ORS) SSS measurements, the coefficient of determination (R2) were 0.81 and 0.92 and the root mean square errors (RMSEs) were 1.30 psu and 0.30 psu, respectively. In addition, a sensitivity analysis revealed the importance of SST and the red-wavelength spectral signal for estimating the SSS. Finally, hourly estimated SSS images were used to illustrate the hourly CDW distribution. With the model developed in this study, the near real-time SSS distribution in the East China Sea (ECS) can be monitored using GOCI and SST data.


2021 ◽  
Vol 13 (14) ◽  
pp. 2676
Author(s):  
Jong-Kuk Choi ◽  
Young-Baek Son ◽  
Myung-Sook Park ◽  
Deuk-Jae Hwang ◽  
Jae-Hyun Ahn ◽  
...  

During the summer season, low-salinity water (LSW) inputs from the Changjiang River are observed as filamentous or lens-like features in the East China Sea. Sea surface salinity (SSS) is an important factor in ocean science, and is used to estimate oceanic carbon fluxes, trace red tides, and calculate other physical processes at the surface. In this study, a proxy was developed using remote sensing reflectance (Rrs) from the Geostationary Ocean Color Imager (GOCI) centered at 490 nm (band 3), 555 nm (band 4), 660 nm (band 5), and 680 nm (band 6), and salinity (data from summer cruises during the period of 2011–2016). It was then validated to map LSW plumes in the East China Sea. The GOCI-derived surface salinity was determined by the empirical relationships between Rrs at the four bands and in situ wave glider SSS data (August 2016), and was validated with synchronous in situ hydrographic SSS data (August 2011, 2012, 2013, and 2016). The GOCI-derived SSS was considered reliable in terms of the validation with the in situ measurement with a high coefficient of determination along with a low RMSE (R2 = 0.803, RMSE = 0.914, N = 21), and in comparisons with two previous models that were used to derive SSS in the East China Sea. The GOCI-derived SSS was successfully used to examine time-series variations on diurnal and daily scales, and the effects of a typhoon in terms of marine physical and biological properties in combination with the chlorophyll-a concentration and sea surface temperature.


2014 ◽  
Vol 119 (10) ◽  
pp. 7016-7028 ◽  
Author(s):  
Seung-bum Kim ◽  
Jae Hak Lee ◽  
Paolo de Matthaeis ◽  
Simon Yueh ◽  
Chang-Su Hong ◽  
...  

2019 ◽  
Vol 229 ◽  
pp. 106415 ◽  
Author(s):  
Wang Hua ◽  
Yan Huaiyu ◽  
Zhou Fengnian ◽  
Li Bao ◽  
Zhuang Wei ◽  
...  

The Holocene ◽  
2016 ◽  
Vol 27 (3) ◽  
pp. 439-449 ◽  
Author(s):  
Yifei Zhao ◽  
Xinqing Zou ◽  
Jianhua Gao ◽  
Chenglong Wang

Although extreme weather events make a strong impact in shallow marine sedimentary environments, there is still a paucity of past records for the Holocene period. Estuarine-inner shelf mud regions deposited from rivers that transport a large amount of suspended sediment represent an important archive of the Holocene. Two cores (S5-2 and JC07) retrieved from the estuarine-inner shelf regions of the East China Sea provided an opportunity to use sensitive grain size and 210Pb dating to reconstruct a history of extreme weather events in the Yangtze River basin. Here, we show that the average sedimentation rates of the two cores, S5-2 (1930–2013) and JC07 (1910–2013), were estimated to be 3.11 and 1.56 cm/yr, respectively. The results indicated that sediment supply played an important role in sedimentation of the estuarine-inner shelf mud region of the East China Sea. Sand content strongly increased in the late 1980s, a result of downstream riverbed erosion of the Yangtze River and submerged deltas. The grain size versus the standard deviation method was used to identify grain-size intervals with the highest variability along a sedimentary sequence. The Yangtze estuary mud area coarse population correlated well with historical literature on Yangtze River floods since AD 1930. Extreme storm events corresponded well with historical literature on the Zhe-Min mud region of the East China Sea. The spectral analyses of the sample core coastal population demonstrated that flood and storm events were consistent with a ~3–8 a periodic change of El Niño Southern Oscillation (ENSO), suggesting that the flood events usually follow ENSO years in the Yangtze River. Consequently, sediment records preserved in the two cores demonstrated different sedimentary responses to Yangtze River floods and storms, which is important to recover centennial scale flood events, to infer extreme precipitation, and to understand climate change in the estuarine-inner shelf of the East China Sea. Nevertheless, more efforts are still needed to simulate paleo-flood and predict future flood events in the context of global warming.


2006 ◽  
Vol 26 (17-18) ◽  
pp. 2141-2156 ◽  
Author(s):  
J.P. Liu ◽  
A.C. Li ◽  
K.H. Xu ◽  
D.M. Velozzi ◽  
Z.S. Yang ◽  
...  

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