The conservative and non-conservative behavior of chromophoric dissolved organic matter in Chinese estuarine waters

Guo, Weidong; Stedmon, Colin A.; Han, Yi; Wu, Fang; Yu, Xiaoyang; Hu, Minghui

doi:10.1016/j.marchem.2007.03.006

Cited by 129 publications

(84 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the Changjiang water input to the ECS probably acts as a source of surface CDOM to offshore areas of the ECS during summer. This is consistent with the results of earlier field studies conducted at the mouth of the Changjiang and near the Chinese coast (Gong 2004;Guo et al 2007) and offshore (Sasaki et al 2008) in the ECS.…”

Section: Cdom Absorption Coefficient From Field Datasupporting

confidence: 92%

“…These studies showed that the CDW has profound effects on the physical and biological processes that occur on the ECS shelf. Previous field studies also showed that CDOM correlated well with SSS from near the Chinese coast to offshore regions in the ECS (Gong 2004;Guo et al 2007;Sasaki et al 2008). Sasaki et al (2008) suggested the notion of tracking the CDW through satellite-based observations of CDOM.…”

Section: Introductionmentioning

confidence: 87%

See 1 more Smart Citation

Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

Sasaki¹,

Gomi²,

Asai³

et al. 2014

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

The optical properties of colored dissolved organic matter (CDOM) in the Changjiang (Yangtze River) plume water were investigated during the summer of 2009 and 2010. The absorption coefficient of CDOM at 325 nm (aCDOM) increased inversely with decreasing sea-surface salinity (SSS), implying that aCDOM can be used as a natural tracer of Changjiangdiluted water (CDW). This aCDOM vs. SSS relationship, however, differed between 2009 and 2010. For mapping the CDW plume, the aCDOM was retrieved from an ocean-color satellite. Values of SSS were also derived from the satellite-retrieved aCDOM using field-based SSS vs. aCDOM relationships. Satellite observations revealed the temporary variable eastward extension of a high aCDOM, low SSS CDW plume in the central East China Sea (ECS) during the summer. The CDW plume during the summer of 2010 extended southeastward from the mouth of the Changjiang (Yangtze River) to almost 26°N. Moreover, the branch of this southeastward CDW plume was seen to extend northeastward to the eastern ECS where the Kuroshio Current flows northeastward along the shelf break. Subsequently, this branch was distributed around southern Kyushu. Satellite observations revealed this unique dispersal of the CDW plume, which illustrates that the aCDOM and SSS from oceancolor satellite data are useful for monitoring the dispersal of this river-water plume.

show abstract

Section: Cdom Absorption Coefficient From Field Datasupporting

confidence: 92%

Section: Introductionmentioning

confidence: 87%

Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

Sasaki¹,

Gomi²,

Asai³

et al. 2014

Terr. Atmos. Ocean. Sci.

View full text Add to dashboard Cite

show abstract

“…Because of its large catchment area (1.94×10 6 km 2 ), the mean annual freshwater discharge is estimated to be 8.94×10 11 m 3 , which accounts for ca. 57% of total runoff inputs to the Chinese coastal waters, with 75% of the runoff inputs discharged during late springsummer (Guo et al, 2007). The YR estuary, extending in an elongated manner and receiving cold low-saline runoff waters mostly through its southern channel, has the continental shelf circulation system mainly comprising of three currents ( Fig.…”

Section: Study Area and Hydrographic Characteristicsmentioning

confidence: 99%

“…The CDOM measured in the ECS (southwest off Jeju Island) are generally at moderate levels (0.3-0.6 m −1 ), largely influenced by high fluvial discharges at the mouth of the YR and advection processes at the offshore areas of the YR mouth. Higher magnitudes are often evident toward the ECS coast, particularly during the peak-runoff periods from late spring-summer (Guo et al, 2007;Tang, 2008).…”

Section: Spectral Variations Of Cdommentioning

confidence: 99%

“…Guo et al (2007) have observed a strong linear and inverse relationship of salinity and a CDOM in surface waters of the Yangtze River (YR) estuary in the ECS. This relationship appears to be consistent with various previous studies in other regions (Jerlov, 1968;Monahan and Pybus, 1978;Boss et al, 2001;Bowers et al, 2000Bowers et al, , 2004Binding and Bowers, 2003;Moon et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Satellite remote sensing of a low-salinity water plume in the East China Sea

et al. 2008

View full text Add to dashboard Cite

Abstract.With the aim to map and monitor a low-salinity water (LSW) plume in the East China Sea (ECS), we developed more robust and proper regional algorithms from large in-situ measurements of apparent and inherent optical properties (i.e. remote sensing reflectance, R rs , and absorption coefficient of coloured dissolved organic matter, a CDOM ) determined in ECS and neighboring waters. Using the above data sets, we derived the following relationships between visible R rs and absorption by CDOM, i.e. R rs (412)/R rs (555) vs. a CDOM (400) (m −1 ) and a CDOM (412) (m −1 ) with a correlation coefficient R 2 0.67 greater than those noted for R rs (443)/R rs (555) and R rs (490)/R rs (555) vs. a CDOM (400) (m −1 ) and a CDOM (412) (m −1 ). Determination of a CDOM (m −1 ) at 400 nm and 412 nm is particularly necessary to describe its absorption as a function of wavelength λ using a single exponential model in which the spectral slope S as a proxy for CDOM composition is estimated by the ratio of a CDOM at 412 nm and 400 nm and the reference is explained simply by a CDOM at 412 nm. In order to derive salinity from the absorption coefficient of CDOM, in-situ measurements of salinity made in a wide range of water types from dense oceanic to light estuarine/coastal systems were used along with in-situ measurements of a CDOM at 400 nm, 412 nm, 443 nm and 490 nm. The CDOM absorption at 400 nm was better inversely correlated (R 2 =0.86) with salinity than at 412 nm, 443 nm and 490 nm (R 2 =0.85-0.66), and this correlation corresponded best with an exponential (R 2 =0.98) rather than a linear function of salinity measured in a variety of water types from this and other regions. Validation against a discrete in-situ data set showed that empirical algorithms derived from the above relationships could be successfully applied to satellite data over the range of water types for which they have been developed. Thus, we applied these algorithms to a series of SeaWiFS images for the derivation Correspondence to: P. Shanmugam (pshanmugam90@hotmail.com) of CDOM and salinity in the context of operational mapping and monitoring of the springtime evolution of LSW plume in the ECS. The results were very encouraging and showed interesting features in surface CDOM and salinity fields in the vicinity of the Yangtze River estuary and its offshore domains, when a regional atmospheric correction (SSMM) was employed instead of the standard (global) SeaWiFS algorithm (SAC) which revealed large errors around the edges of clouds/aerosols while masking out the nearshore areas. Nevertheless, there was good consistency between these two atmospheric correction algorithms over the relatively clear regions with a mean difference of 0.009 in a CDOM (400) (m −1 ) and 0.096 in salinity (psu). This study suggests the possible utilization of satellite remote sensing to assess CDOM and salinity and thus provides great potential in advancing our knowledge of the shelf-slope evolution and migration of the LSW plume properties in the ECS.

show abstract

Runoff‐mediated seasonal oscillation in the dynamics of dissolved organic matter in different branches of a large bifurcated estuary—The Changjiang Estuary

et al. 2014

Self Cite

View full text Add to dashboard Cite

The Changjiang Estuary is a large bifurcated estuary where different hydrodynamic processes influence its South Branch compared to its North Branch. The South Branch is the dominant pathway of Changjiang River discharge, while the shallower and narrower North Branch is dominated by salt water intrusion, especially in the dry season. Absorption and fluorescence spectroscopy were measured along with dissolved organic carbon (DOC) concentrations to characterize the properties of dissolved organic matter (DOM) collected in different seasons during an extreme drought year in 2011. The refractory DOM from the Changjiang River flowed mainly through the South Branch, whereas in the lower South Branch, the input from the polluted Huangpu River contributed a large amount of biolabile DOM, demonstrating an anthropogenic perturbation from megacities. The DOM properties in the North Branch showed conservative behavior in the wet season, while noticeable addition was observed in the dry season, accompanied by the reversed flux of DOM from the North Branch to the South Branch, emphasizing the regular seasonal oscillation of the DOM dynamics in this monsoon-controlled bifurcated estuary. The estuarine turbidity maximum zones played distinct roles on DOM dynamics in different estuarine environments. The DOC and chromophoric DOM (CDOM) abundance in the Changjiang River and other Chinese rivers were at lower levels compared to other world rivers, showing a characteristic of the regional CDOM-poor features for many East Asia rivers.

show abstract

The conservative and non-conservative behavior of chromophoric dissolved organic matter in Chinese estuarine waters

Cited by 129 publications

References 45 publications

Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

Unique Dispersal of the Changjiang-Diluted Water Plume in the East China Sea Revealed from Satellite Monitoring of Colored Dissolved Organic Matter (CDOM)

Satellite remote sensing of a low-salinity water plume in the East China Sea

Runoff‐mediated seasonal oscillation in the dynamics of dissolved organic matter in different branches of a large bifurcated estuary—The Changjiang Estuary

Contact Info

Product

Resources

About