scholarly journals Effects of flooding on organic carbon consumption in the East China Sea

2015 ◽  
Vol 12 (7) ◽  
pp. 5609-5639 ◽  
Author(s):  
C.-C. Chen ◽  
G.-C. Gong ◽  
W.-C. Chou ◽  
C.-C. Chung ◽  
F.-K. Shiah ◽  
...  
Keyword(s):  
East China Sea ◽  
Sea Surface Salinity ◽  
East China ◽  
Community Respiration ◽  
The East China Sea ◽  
Surface Salinity ◽  
Mean Values ◽  
China Sea ◽  
Flood Period ◽  
The Mean

Abstract. This study was designed to determine the effects of flooding on plankton community respiration (CR) in the East China Sea (ECS). In July 2010, a devastating flood occurred in the Changjiang River; the mean monthly discharge was 60 527 m3 s−1. To compare, the variables were also examined in the low riverine flow of July 2009 (33 955 m3 s−1). During the flooding, the Changjiang diluted water (CDW) zone, the sea surface salinity (SSS) was ≤ 31 psu, covering almost two thirds of the ECS, which was approximately six times that in the non-flooding period. The mean nitrate concentration was higher in 2010 (6.2 μM) than in 2009 (2.0 μM). However, in the 2010 flood, the mean values of Chl a and the bacterial biomass were only slightly higher or even lower than in 2009. Surprisingly, however, the CR was still higher in the flood period than in the non-flood period, with mean values of 105.6 and 73.2 mg C m−3 d−1, respectively. The higher CR in 2010 could be attributed to vigorous plankton activities, especially phytoplankton, at stations in the CDW zone, which were not mostly covered by low SSS in 2009. There was a huge amount of fCO2 drawdown in the 2010 flood. These results suggested that the devastating flood in 2010 had a significant effect on the carbon balance in the ECS. This effect might become more pronounced as extreme rainfall events and flooding magnitudes increase dramatically throughout the world.

scholarly journals The influence of episodic flooding on a pelagic ecosystem in the East China Sea

2017 ◽  
Vol 14 (10) ◽  
pp. 2597-2609 ◽  
Author(s):  
Chung-Chi Chen ◽  
Gwo-Ching Gong ◽  
Wen-Chen Chou ◽  
Chih-Ching Chung ◽  
Chih-Hao Hsieh ◽  
...  
Keyword(s):  
East China Sea ◽  
Extreme Rainfall ◽  
Sea Surface Salinity ◽  
East China ◽  
Community Respiration ◽  
The East China Sea ◽  
Pelagic Ecosystem ◽  
Surface Salinity ◽  
China Sea ◽  
Flooding Period

Abstract. This study was designed to determine the effects of flooding on a pelagic ecosystem in the East China Sea (ECS) with a focus on plankton activity and plankton community respiration (CR). In July 2010, a flood occurred in the Changjiang River. As a comparison, a variety of abiotic and biotic parameters were monitored during this flooding event and during a non-flooding period (July 2009). During the flood, the Changjiang diluted water (CDW) zone covered almost two-thirds of the ECS, which was approximately 6 times the area covered during the non-flooding period. The mean nitrate concentration was 3-fold higher during the 2010 flood (6.2 vs. 2.0 µM in 2009). CR was also higher in the 2010 flood: 105.6 mg C m−3 d−1 vs. only 73.2 mg C m−3 d−1 in 2009. The higher CR in 2010 could be attributed to phytoplankton respiration, especially at stations in the CDW zone that were not previously characterized by low sea surface salinity in 2009. In addition, zooplankton (> 330 µm) were another important component contributing to the high CR rate observed during the 2010 flood; this was a period also associated with a significant degree of fCO2 drawdown. These results collectively suggest that the 2010 flood had a significant effect on the carbon balance in the ECS. This effect might become more pronounced in the future, as extreme rainfall and flooding events are predicted to increase in both frequency and magnitude due to climate change.

scholarly journals The influence of episodic flooding on pelagic ecosystem in the East China Sea

2016 ◽  
Author(s):  
Chung-Chi Chen ◽  
Gwo-Ching Gong ◽  
Wen-Chen Chou ◽  
Chih-Ching Chung ◽  
Chih-Hao Hsieh ◽  
...  
Keyword(s):  
East China Sea ◽  
East China ◽  
Community Respiration ◽  
The East China Sea ◽  
Pelagic Ecosystem ◽  
Mean Values ◽  
Chl A ◽  
China Sea ◽  
The Mean ◽  
Flooding Period

Abstract. This study was designed to determine the effects of flooding on pelagic ecosystem in the East China Sea (ECS), especially on plankton community respiration (CR). In July 2010, a flood occurred in the Changjiang River. As a comparison, a variety of both abiotic and biotic parameters were monitored, as well as in July 2009, a non-flooding period. During the flooding, the Changjiang diluted water (CDW) zone covered almost two thirds of the ECS, which was approximately six times that of the non-flooding period. The mean nitrate concentration was higher in 2010 (6.2 μM) than in 2009 (2.0 μM). However, during the 2010 flood, the mean values of Chl a and bacterial biomass were only slightly higher or even lower than in 2009. However, the CR was still higher in 2010 than in 2009, with mean values of 105.6 and 73.2 mg C m−3 d−1, respectively. The higher CR in 2010 could be attributed to vigorous plankton metabolic activities, especially phytoplankton, at stations in the CDW zone, which were not characterized by low SSS in 2009. In addition, zooplankton might be another important component contributing to the high CR rate observed in 2010. Furthermore, there was a significant amount of fCO2 drawdown in the 2010 flood. These results suggest that the flood in 2010 had a significant effect on the carbon balance in the ECS. This effect might become more pronounced in the future, as extreme rainfall events and flooding magnitudes are predicted to increase globally due to climate change.

scholarly journals Estimation of Hourly Sea Surface Salinity in the East China Sea Using Geostationary Ocean Color Imager Measurements

2020 ◽  
Vol 12 (5) ◽  
pp. 755
Author(s):  
Dae-Won Kim ◽  
Young-Je Park ◽  
Jin-Yong Jeong ◽  
Young-Heon Jo
Keyword(s):  
Real Time ◽  
East China Sea ◽  
Ocean Color ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
East China ◽  
The East China Sea ◽  
Surface Salinity ◽  
China Sea ◽  
Mean Square Errors

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.

scholarly journals The Applicability of the Geostationary Ocean Color Imager to the Mapping of Sea Surface Salinity in the East China Sea

2021 ◽  
Vol 13 (14) ◽  
pp. 2676
Author(s):  
Jong-Kuk Choi ◽  
Young-Baek Son ◽  
Myung-Sook Park ◽  
Deuk-Jae Hwang ◽  
Jae-Hyun Ahn ◽  
...  
Keyword(s):  
East China Sea ◽  
Ocean Color ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
East China ◽  
Red Tides ◽  
The East China Sea ◽  
Surface Salinity ◽  
China Sea

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.

scholarly journals Sea surface salinity variability in the East China Sea observed by the Aquarius instrument

2014 ◽  
Vol 119 (10) ◽  
pp. 7016-7028 ◽  
Author(s):  
Seung-bum Kim ◽  
Jae Hak Lee ◽  
Paolo de Matthaeis ◽  
Simon Yueh ◽  
Chang-Su Hong ◽  
...  
Keyword(s):  
East China Sea ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
East China ◽  
The East China Sea ◽  
Surface Salinity ◽  
China Sea ◽  
Salinity Variability

scholarly journals Importance of planktonic community respiration on the carbon balance of the East China Sea in summer

2006 ◽  
Vol 20 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Chung-Chi Chen ◽  
Kuo-Ping Chiang ◽  
Gwo-Ching Gong ◽  
Fuh-Kwo Shiah ◽  
Chun-Mao Tseng ◽  
...  
Keyword(s):  
East China Sea ◽  
Carbon Balance ◽  
East China ◽  
Community Respiration ◽  
The East China Sea ◽  
China Sea ◽  
Planktonic Community

scholarly journals The large variation in organic carbon consumption in spring in the East China Sea

2012 ◽  
Vol 9 (11) ◽  
pp. 16533-16564
Author(s):  
C.-C. Chen ◽  
G.-C. Gong ◽  
F.-K. Shiah ◽  
W.-C. Chou ◽  
C.-C. Hung
Keyword(s):  
Organic Carbon ◽  
East China Sea ◽  
Phytoplankton Growth ◽  
East China ◽  
Community Respiration ◽  
Changjiang River ◽  
Carbon Consumption ◽  
The East China Sea ◽  
China Sea ◽  
The Changjiang River

Abstract. A tremendous amount of organic carbon respired by planktonic communities has been found in summer in the East China Sea (ECS), and this rate has been significantly correlated with fluvial discharge from the Changjiang River. However, data related to this issue in other seasons have rarely been collected. To evaluate and reveal the potential controlling mechanism of organic carbon consumption in spring in the ECS, research using stations covering almost the entire ECS shelf was conducted in the spring of 2009 and 2010. During both periods, the fluvial discharges were similar, and these rates were comparable to high riverine flow in summer. Interestingly, planktonic community respiration (CR) varied widely in both springs; in 2009, the level of CR was double that of 2010, with mean (± SD) values of 111.7 (± 76.3) and 50.7 (± 62.9) mg C m−3 d−1, respectively. The CR was positively linearly regressed with concentrations of particulate organic carbon and/or chlorophyll a (Chl a) in 2009 (all p< 0.01). These results suggest that the rate was dependent on planktonic activities, especially that of phytoplankton, in 2009. During this period, phytoplankton growth flourished due to allochthonous nutrients discharged from the Changjiang River. Furthermore, higher phytoplankton growth leaded to the absorption of an enormous amount of fugacity of CO2 (fCO2) in the surface waters, even with a significant amount of inorganic carbon regenerated via CR. In 2010, there were even more riverine runoff nutrients into the ECS than in 2009. Surprisingly, the growth of phytoplankton in 2010 was not stimulated by enriched nutrients, and its growth was likely limited by low water temperature and/or low light intensity. Low temperature might also suppress planktonic metabolism, and this could explain why the CR was lower in 2010. During this period, lower surface water fCO2 might have mainly been driven by physical process(es). To conclude, these results indicate that organic carbon consumption (i.e. CR) in the ECS in spring might be controlled by the magnitude of planktonic activities and physical factor (e.g. temperature), and that the latter is especially important during a cold spring season. This further suggests that the high intraseasonal variability of organic carbon consumption needs to be kept in mind when budgeting the annual carbon balance.

Sign in / Sign up

Export Citation Format

Share Document