scholarly journals Potential of High Spatial and Temporal Ocean Color Satellite Data to Study the Dynamics of Suspended Particles in a Micro-Tidal River Plume

2016 ◽  
Vol 8 (3) ◽  
pp. 245 ◽  
Author(s):  
Anouck Ody ◽  
David Doxaran ◽  
Quinten Vanhellemont ◽  
Bouchra Nechad ◽  
Stefani Novoa ◽  
...  
Keyword(s):  
Satellite Data ◽  
Ocean Color ◽  
Suspended Particles ◽  
River Plume ◽  
Tidal River

scholarly journals Freshwater Composition and Connectivity of the Connecticut River Plume During Ambient Flood Tides

2021 ◽  
Vol 8 ◽  
Author(s):  
Michael M. Whitney ◽  
Yan Jia ◽  
Kelly L. Cole ◽  
Daniel G. MacDonald ◽  
Kimberly D. Huguenard
Keyword(s):  
Mixing Time ◽  
Growth Period ◽  
Tidal Currents ◽  
Surface Flow ◽  
River Plume ◽  
Tidal River ◽  
Initial Growth ◽  
Connecticut River ◽  
Tidal Period ◽  
Source Waters

The Connecticut River plume interacts with the strong tidal currents of the ambient receiving waters in eastern Long Island Sound. The plume formed during ambient flood tides is studied as an example of tidal river plumes entering into energetic ambient tidal environments in estuaries or continental shelves. Conservative passive freshwater tracers within a high-resolution nested hydrodynamic model are applied to determine how source waters from different parts of the tidal cycle contribute to plume composition and interact with bounding plume fronts. The connection to source waters can be cut off only under low-discharge conditions, when tides reverse surface flow through the mouth after max ambient flood. Upstream plume extent is limited because ambient tidal currents arrest the opposing plume propagation, as the tidal internal Froude number exceeds one. The downstream extent of the tidal plume always is within 20 km from the mouth, which is less than twice the ambient tidal excursion. Freshwaters in the river during the preceding ambient ebb are the oldest found in the new flood plume. Connectivity with source waters and plume fronts exhibits a strong upstream-to-downstream asymmetry. The arrested upstream front has high connectivity, as all freshwaters exiting the mouth immediately interact with this boundary. The downstream plume front has the lowest overall connectivity, as interaction is limited to the oldest waters since younger interior waters do not overtake this front. The offshore front and inshore boundary exhibit a downstream progression from younger to older waters and decreasing overall connectivity with source waters. Plume-averaged freshwater tracer concentrations and variances both exhibit an initial growth period followed by a longer decay period for the remainder of the tidal period. The plume-averaged tracer variance is increased by mouth inputs, decreased by entrainment, and destroyed by internal mixing. Peak entrainment velocities for younger waters are higher than values for older waters, indicating stronger entrainment closer to the mouth. Entrainment and mixing time scales (1–4 h at max ambient flood) are both shorter than half a tidal period, indicating entrainment and mixing are vigorous enough to rapidly diminish tracer variance within the plume.

scholarly journals From Validation Statistics to Uncertainty Estimates: Application to VIIRS Ocean Color Radiometric Products at European Coastal Locations

2021 ◽  
Vol 8 ◽  
Author(s):  
Frédéric Mélin
Keyword(s):  
Satellite Data ◽  
Field Data ◽  
Spectral Characteristics ◽  
Ocean Color ◽  
Field Measurements ◽  
Uncertainty Budget ◽  
Field Observations ◽  
Validation Process ◽  
Uncertainty Estimates ◽  
European Seas

Uncertainty estimates are needed to assess ocean color products and qualify the agreement between missions. Comparison between field observations and satellite data, a process defined as validation, has been the traditional way to assess satellite products. However validation statistics can provide only an approximation for satellite data uncertainties as field measurements have their own uncertainties and as the validation process is imperfect, comparing data potentially differing in temporal, spatial or spectral characteristics. This study describes a method to interpret in terms of uncertainties the validation statistics obtained for ocean color remote sensing reflectance RRS knowing the uncertainties associated with field data. This approach is applied to observations collected at sites part of the Ocean Color component of the Aerosol Robotic Network (AERONET-OC) located in coastal regions of the European seas, and to RRS data from the VIIRS sensors on-board the SNPP and JPSS1 platforms. Similar estimates of uncertainties σVRS (term accounting for non-systematic contributions to the uncertainty budget) are obtained for both missions, decreasing with wavelength from the interval 0.8–1.4 10−3 sr−1 in the blue to a maximum of 0.24 10−3 sr−1 in the red, values that are at least twice (but up to 8 times) the uncertainties reported for the field data. These uncertainty estimates are then used to qualify the agreement between the VIIRS products, defining the extent to which they agree within their stated uncertainty. Despite significant biases between the two missions, their RRS products appear fairly compatible.

scholarly journals Investigating Rhône River plume (Gulf of Lions, France) dynamics using metrics analysis from the MERIS 300m Ocean Color archive (2002–2012)

2017 ◽  
Vol 144 ◽  
pp. 98-111 ◽  
Author(s):  
Aurélien Gangloff ◽  
Romaric Verney ◽  
David Doxaran ◽  
Anouck Ody ◽  
Claude Estournel
Keyword(s):  
Ocean Color ◽  
River Plume ◽  
Rhône River ◽  
Gulf Of Lions ◽  
Rhone River
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