Spreading dynamics of small river plumes off the northeastern coast of the Black Sea observed by Landsat 8 and Sentinel-2

Osadchiev, Alexander; Sedakov, Roman

doi:10.1016/j.rse.2018.11.043

Cited by 51 publications

(43 citation statements)

References 88 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The considered upwelling events can also strongly influence primary productivity and local food webs. Upwelling causes upward penetration of nutrient-rich sea water [35,[43][44][45][46][47]106], which is especially important for nutrient-poor areas at the shelf of the Laptev and East-Siberian seas where vertical convection is inhibited by strong stratification formed by large continental runoff. In particular, elevated concentrations of nitrates and increased biological productivity were reported in the vicinity of the upwelling area located near the Lena Delta shortly after an upwelling event [32].…”

Section: Discussionmentioning

confidence: 99%

“…Turbid regions associated with river plumes are adjacent to river estuaries and deltas. Spatial and temporal variability of these regions is defined mainly by river discharge rate, turbidity of river water, and local wind forcing [39][40][41][42][43][44][45][46][47]. Coastal erosion in the Laptev and East-Siberian seas is extremely intense due to active thermal abrasion.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Wind-Driven Coastal Upwelling near Large River Deltas in the Laptev and East-Siberian Seas

2020

Self Cite

View full text Add to dashboard Cite

The Lena, Kolyma, and Indigirka rivers are among the largest rivers that inflow to the Arctic Ocean. Their discharges form a freshened surface water mass over a wide area in the Laptev and East-Siberian seas and govern many local physical, geochemical, and biological processes. In this study we report coastal upwelling events that are regularly manifested on satellite imagery by increased sea surface turbidity and decreased sea surface temperature at certain areas adjacent to the Lena Delta in the Laptev Sea and the Kolyma and Indigirka deltas in the East-Siberian Sea. These events are formed under strong easterly and southeasterly wind forcing and are estimated to occur during up to 10%-30% of ice-free periods at the study region. Coastal upwelling events induce intense mixing of the Lena, Kolyma, and Indigirka plumes with subjacent saline sea. These plumes are significantly transformed and diluted while spreading over the upwelling areas; therefore, their salinity and depths abruptly increase, while stratification abruptly decreases in the vicinity of their sources. This feature strongly affects the structure of the freshened surface layer during ice-free periods and, therefore, influences circulation, ice formation, and many other processes at the Laptev and East-Siberian seas.Remote Sens. 2020, 12, 844 2 of 25 seas and are among the largest freshwater reservoirs in the Arctic Ocean [17][18][19][20]. Spreading and transformation of these river plumes determine vertical stratification and, therefore, strongly affect circulation and ice formation in the Laptev and East-Siberian seas, as well as many other physical, geochemical, and biological processes [21][22][23][24][25][26][27][28][29][30][31][32].In this study we focus on upwelling events which regularly occur at coastal areas adjacent to the deltas of the Lena, Kolyma, and Indigirka rivers. Surface manifestations of these upwelling events are visible on ocean color satellite imagery due to elevated turbidity and on sea surface temperature (SST) satellite imagery due to reduced temperature. However, correct identification of the origin of SST and turbidity features observed on satellite imagery is not a straightforward task. SST features in the study region are formed as a result of interaction between water masses with different temperature, namely, warm river plumes and cold saline sea water, and are associated with spreading of river plumes, mixing of surface layer with subjacent sea, and ice melting. Areas of elevated sea surface turbidity in coastal and shelf regions are commonly associated with four different processes: spreading of turbid river plumes, coastal erosion, resuspension of bottom sediments penetrated to sea surface, and algal blooms [33]. The first three processes are common features of the Laptev and East-Siberian seas [25,27,34,35], while algal blooms do not occur in these seas [32,[36][37][38]. Turbid regions associated with river plumes are adjacent to river estuaries and deltas. Spatial and temporal variability of these regions is def...

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Wind-Driven Coastal Upwelling near Large River Deltas in the Laptev and East-Siberian Seas

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…This impact is not negligible; in particular, intensification of the Rim Current enhances alongshore spreading of the AP, while the mesoscale anticyclonic eddy formed between the Rim Current and the Kerch Peninsula induces cross-shore spreading of the AP (Kubryakov et al, 2019). However, the obtained relations and numerical modelling results show that spreading of the AP is mainly governed by wind forcing, while coastal circulation plays a secondary role, which is typical for buoyant surface-advected water masses (Washburn et al, 2003;Ostrander et al, 2008;Osadchiev and Zavialov, 2013;and Osadchiev, 2015).…”

Section: Spreading Of the Ap In The Black Seamentioning

confidence: 90%

“…Thus, we obtain the result that AI events are induced by wind forcing and do not depend on river discharge conditions on a synoptic timescale. Spreading of a buoyant plume in a non-tidal sea is mainly governed by the discharge rate and wind forcing (Fong et al, 1997;Hallock and Marmorino, 2002;Horner-Devine et al, 2015;and Osadchiev and Sedakov, 2019) and is characterized by strong variability in size, shape, and spreading patterns under different configurations of external forcing conditions (Kourafalou et al, 1996;Xia et al, 2007;Zavialov et al, 2014;Osadchiev et al, 2016and Osadchiev and Korshenko, 2017). However, analysis of satellite imagery and numerical modelling revealed the stability of the spreading pattern of the AP.…”

Section: Spreading Of the Ap In The Black Seamentioning

confidence: 99%

Water exchange between the Sea of Azov and the Black Sea through the Kerch Strait

et al. 2020

Self Cite

View full text Add to dashboard Cite

The Sea of Azov is a small, shallow, and freshened sea that receives a large freshwater discharge. Under certain external forcing conditions low-salinity waters from the Sea of Azov flow into the north-eastern part of the Black Sea through the narrow Kerch Strait and form a surface-advected buoyant plume. Water flow in the Kerch Strait also regularly occurs in the opposite direction, which results in the spreading of a bottom-advected plume of saline and dense waters from the Black Sea into the Sea of Azov. In this study we focus on the physical mechanisms that govern water exchange through the Kerch Strait and analyse the dependence of its direction and intensity on external forcing conditions. Analysis of satellite imagery, wind data, and numerical modelling shows that water exchange in the Kerch Strait is governed by a wind-induced barotropic pressure gradient. Water flow through the shallow and narrow Kerch Strait is a one-way process for the majority of the time. Outflow from the Sea of Azov to the Black Sea is induced by moderate and strong north-easterly winds, while flow into the Sea of Azov from the Black Sea occurs during wind relaxation periods. The direction and intensity of water exchange have wind-governed synoptic and seasonal variability, and they do not depend on the rate of river discharge to the Sea of Azov on an intraannual timescale. The analysed data reveal dependencies between wind forcing conditions and spatial characteristics of the buoyant plume formed by the outflow from the Sea of Azov.Published by Copernicus Publications on behalf of the European Geosciences Union.

show abstract

“…We used near-simultaneous ocean-color satellite imagery from NASA's Landsat 8 and ESA's Sentinel-2 missions to reconstruct surface currents along RCBS and study spreading dynamics of small river plumes formed in this area [53]. Several times a year, Landsat 8 and Sentinel-2 satellites both pass over the study area within a time interval of less than 10 minutes.…”

Section: Wind Forcing and Small River Plumesmentioning

confidence: 99%

Structure and Dynamics of Plumes Generated by Small Rivers

Osadchiev¹,

Zavialov²

2020

Estuaries and Coastal Zones - Dynamics and Response to Environmental Changes

Self Cite

View full text Add to dashboard Cite

The total share of small rivers in the influxes of fluvial water and suspended matter to the world ocean is estimated at between 25 and 40%. On a regional scale, this contribution can be even more significant for many coastal regions. In this chapter, we show that dynamics of small river plumes is significantly different from that of plumes generated by large rivers. Spatial structure of small plumes is generally characterized by sharper horizontal and vertical gradients. As a result, small plumes exhibit more energetic temporal variability in response to external forcing. In this chapter, we address several dynamical features typical for small plumes. We describe and discuss the response of small plumes to wind forcing and river discharge variability, the interaction between neighboring small plumes, and the generation of high-frequency internal waves in coastal ocean by small rivers. We also substantiate the Lagrangian approach to numerical modeling of small river plumes.

show abstract

Spreading dynamics of small river plumes off the northeastern coast of the Black Sea observed by Landsat 8 and Sentinel-2

Cited by 51 publications

References 88 publications

Wind-Driven Coastal Upwelling near Large River Deltas in the Laptev and East-Siberian Seas

Wind-Driven Coastal Upwelling near Large River Deltas in the Laptev and East-Siberian Seas

Water exchange between the Sea of Azov and the Black Sea through the Kerch Strait

Structure and Dynamics of Plumes Generated by Small Rivers

Contact Info

Product

Resources

About