Influence of estuarine tidal mixing on structure and spatial scales of large river plumes

Osadchiev, Alexander; Medvedev, Igor; Щука, С. А.; Kulikov, Mikhail E.; Spivak, Eduard; Pisareva, Maria N.; Semiletov, I. P.

doi:10.5194/os-16-781-2020

Cited by 28 publications

(25 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Khatanga discharge experienced intense estuarine tidal mixing and therefore was distributed from surface to the bottom in the inner estuary and over the 20-25 m deep water column in the outer estuary, see Section 3.2.2 and the study of Osadchiev et al [48]. The difference in DOC concentration and CDOM absorption between the upper and deep waters was, therefore, not as pronounced as for the Kara Sea and the Lena Delta region Tables 1 and 2.…”

Section: Laptev Seamentioning

confidence: 89%

“…The vertical salinity structure and distribution of freshwater fraction at the transect from the Khatanga River estuary to the continental slope are discussed in detail by Osadchiev et al [48]. Shortly, the Khatanga plume was weakly-stratified and occupied the whole water column in the shallow inner part of the estuary (stations 5627-2629) due to intense tidal mixing in the Khatanga Gulf.…”

Section: Laptev Seamentioning

confidence: 99%

See 1 more Smart Citation

CDOM Optical Properties and DOC Content in the Largest Mixing Zones of the Siberian Shelf Seas

et al. 2021

View full text Add to dashboard Cite

Notable changes in the Arctic ecosystem driven by increased atmospheric temperature and ice cover reduction were observed in the last decades. Ongoing environmental shifts affect freshwater discharge to the Arctic Ocean, and alter Arctic land-ocean fluxes. The monitoring of DOC distribution and CDOM optical properties is of great interest both from the point of view of validation of remote sensing models, and for studying organic carbon transformation and dynamics. In this study we report the DOC concentrations and CDOM optical characteristics in the mixing zones of the Ob, Yenisei, Khatanga, Lena, Kolyma, and Indigirka rivers. Water sampling was performed in August–October 2015 and 2017. The DOC was determined by high-temperature combustion, and absorption coefficients and spectroscopic indices were calculated using the seawater absorbance obtained with spectrophotometric measurements. Kara and Laptev mixing zones were characterized by conservative DOC behavior, while the East Siberian sea waters showed nonconservative DOC distribution. Dominant DOM sources are discussed. The absorption coefficient aCDOM (350) in the East Siberian Sea was two-fold lower compared to Kara and Laptev seawaters. For the first time we report the DOC content in the Khatanga River of 802.6 µM based on the DOC in the Khatanga estuary.

show abstract

Section: Laptev Seamentioning

confidence: 89%

Section: Laptev Seamentioning

confidence: 99%

CDOM Optical Properties and DOC Content in the Largest Mixing Zones of the Siberian Shelf Seas

et al. 2021

View full text Add to dashboard Cite

show abstract

“…They are covered by ice most of the year. Sea ice formation during the winter season and its melting in summer as well as spreading and transformation of river plumes has a major impact on physical and biogeochemical conditions of the East Siberian and Laptev seas (Dmitrenko et al, 2005;Savel'eva et al, 2008;Osadchiev et al, 2020).The spring flood occurs from the end of May to the beginning of July and constitutes 60%-90% of the riverine freshwater discharge (Raymond et al, 2007). The Laptev Sea receives large freshwater discharge from the Lena (590 km 3 yr -1 ), Khatanga (105 km 3 yr -1 ), Olenyok (36 km 3 yr -1 ), and Yana (36 km 3 yr -1 ) rivers.…”

Section: Study Areamentioning

confidence: 99%

“…The Laptev Sea receives large freshwater discharge from the Lena (590 km 3 yr -1 ), Khatanga (105 km 3 yr -1 ), Olenyok (36 km 3 yr -1 ), and Yana (36 km 3 yr -1 ) rivers. The East Siberian Sea is supplied by seawater from both the Atlantic and Pacific Oceans (Semiletov et al, 2005) and has a substantial input of Kolyma (136 km 3 yr -1 ) and Indigirka (61 km 3 yr -1 ) river runoff providing about 75% of the total freshwaters discharge to the East Siberian Sea (Pavlov et al, 1994;Gordeev et al, 1996;Holmes et al, 2002;Osadchiev et al, 2020). The western region is dominated by input of terrestrialderived material from the Laptev Sea (Alling et al, 2010).…”

Section: Study Areamentioning

confidence: 99%

Fluorescent signatures of autochthonous dissolved organic matter production in Siberian shelf seas

Drozdova

Krylov²,

Nedospasov³

et al. 2022

Front. Mar. Sci.

View full text Add to dashboard Cite

The East Siberian Sea is an area of high biogeochemical activity caused by multiple factors, such as an influence of river runoff, Atlantic, and Pacific waters, formation and melting of sea ice, and internal circulation. Extensive amounts of carbon are accumulated in sub-sea permafrost within the Arctic shelf in East Siberia. Thawing permafrost and resulting microbial decomposition of frozen carbon pool is a potential feedback process affected global climate dynamics. Several studies of dissolved organic carbon (DOC) distribution in the East Siberian Sea have demonstrated untypical for other Arctic shelf seas pronounced non-conservative DOC behavior. Using seawater samples from the 69th cruise of R/V Akademik Mstislav Keldysh conducted in the Laptev and East Siberian seas in September 2017, this study examines the distribution of fluorescent dissolved organic matter (FDOM) along the shelf-crossing transects including the areas affected by the Khatanga, Lena, Indigirka, and Kolyma river runoff. The set of 137 excitation-emission matrices (EEMs), analyzed with Parallel Factor analysis (PARAFAC), was described by a 4-component model demonstrating Tucker’s congruence coefficient above the 0.95 threshold. Spectral characteristics of the resulting components allowed identifying them as well-known humic-like A and C, protein-like B/T, and marine humic-like M fluorophores. Component C1 (A fluorophore) showed a good correlation with salinity for different river plume influenced regions. As well as chromophoric DOM (CDOM) absorption, it can be used as marker of input of terrestrial DOM to the Arctic Ocean. A distinctive feature of the East Siberian Sea shelf waters in comparison with the Laptev Sea is the higher content of the C2 and C4 components, exhibiting protein-like and marine humic-like fluorescence. Component C3 (C fluorophore) which is usually identified as terrestrial-derived material, was found to be produced locally on the East Siberian Sea shelf and in the continental slope region of the Khatanga transect. Destruction of dead algae cells, production of marine biota and dissolved organic matter (DOM) reworking are considered as possible autochthonous FDOM sources in the Siberian shelf seas.

show abstract

“…However, these river plumes affect a number of key physical, biological and geochemical processes (water balance, stratification, nutrient cycle, carbon cycle, acidification, etc.) across large marine areas including the Bay of Bengal [28,56,57], the South China Sea [58], the central Atlantic [59,60], and the Arctic Ocean [8,9,[35][36][37][61][62][63]. Moreover, spreading and mixing of Ob-Yenisei and Lena plumes in the Arctic Ocean determine the sea stratification in the area of seasonal sea ice formation, thereby affecting ice formation in the Arctic Ocean, seasonal variability in the Earth's albedo and planetary climate [64,65].…”

Section: Discussionmentioning

confidence: 99%

Large River Plumes Detection by Satellite Altimetry: Case Study of the Ob–Yenisei Plume

Frey

Osadchiev

2021

Remote Sensing

Self Cite

View full text Add to dashboard Cite

Satellite altimetry is an efficient instrument for detection dynamical processes in the World Ocean, including reconstruction of geostrophic currents and tracking of mesoscale eddies. Satellite altimetry has the potential to detect large river plumes, which have reduced salinity and, therefore, elevated surface level as compared to surrounding saline sea. In this study, we analyze applicability of satellite altimetry for detection of the Ob–Yenisei plume in the Kara Sea, which is among the largest river plumes in the World Ocean. Based on the extensive in situ data collected at the study area during oceanographic surveys in 2007–2019, we analyze the accuracy and efficiency of satellite altimetry in reproducing, first, the outer boundary of the plume and, second, the internal structure of the plume. We reveal that the value of positive level anomaly within the Ob–Yenisei plume strongly depends on the vertical plume structure and is prone to significant synoptic and seasonal variability due to wind forcing and mixing of the plume with subjacent sea. As a result, despite generally high statistical correlation between the ADT and surface salinity, straightforward usage of ADT for detection of the river plume is incorrect and produces misleading results. Satellite altimetry could provide correct information about spatial extents and shape of the Ob–Yenisei plume only if it is validated by synchronous in situ measurements.

show abstract

Influence of estuarine tidal mixing on structure and spatial scales of large river plumes

Cited by 28 publications

References 61 publications

CDOM Optical Properties and DOC Content in the Largest Mixing Zones of the Siberian Shelf Seas

CDOM Optical Properties and DOC Content in the Largest Mixing Zones of the Siberian Shelf Seas

Fluorescent signatures of autochthonous dissolved organic matter production in Siberian shelf seas

Large River Plumes Detection by Satellite Altimetry: Case Study of the Ob–Yenisei Plume

Contact Info

Product

Resources

About