Remotely sensed data can reinforce the abilities of water resources researchers and decision makers to monitor waterbodies more effectively. Remote sensing techniques have been widely used to measure the qualitative parameters of waterbodies (i.e., suspended sediments, colored dissolved organic matter (CDOM), chlorophyll-a, and pollutants). A large number of different sensors on board various satellites and other platforms, such as airplanes, are currently used to measure the amount of radiation at different wavelengths reflected from the water’s surface. In this review paper, various properties (spectral, spatial and temporal, etc.) of the more commonly employed spaceborne and airborne sensors are tabulated to be used as a sensor selection guide. Furthermore, this paper investigates the commonly used approaches and sensors employed in evaluating and quantifying the eleven water quality parameters. The parameters include: chlorophyll-a (chl-a), colored dissolved organic matters (CDOM), Secchi disk depth (SDD), turbidity, total suspended sediments (TSS), water temperature (WT), total phosphorus (TP), sea surface salinity (SSS), dissolved oxygen (DO), biochemical oxygen demand (BOD) and chemical oxygen demand (COD).

/pdf/a-comprehensive-review-on-water-quality-parameters-2t54o9y6tk.pdf

A Comprehensive Review on Water Quality Parameters Estimation Using Remote Sensing Techniques.

Soil Moisture and Ocean Salinity, European Space Agency, is the first satellite mission addressing the challenge of measuring sea surface salinity from space It uses an L-band microwave interferometric radiometer with aperture synthesis (MIRAS) that generates brightness temperature images, from which both geophysical variables are computed The retrieval of salinity requires very demanding performances of the instrument in terms of calibration and stability This paper highlights the importance of ocean salinity for the Earth's water cycle and climate; provides a detailed description of the MIRAS instrument, its principles of operation, calibration, and image-reconstruction techniques; and presents the algorithmic approach implemented for the retrieval of salinity from MIRAS observations, as well as the expected accuracy of the obtained results

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SMOS: The Challenging Sea Surface Salinity Measurement From Space

Delta morphology is thought to be controlled by factors such as river discharge, tides and waves. Numerical modelling shows that sediment cohesion also strongly influences the development of a delta’s characteristics. The morphologies of the world’s deltas are thought to be determined by river discharge, tidal range and wave action 1. More recently, sea-level rise 2,3 and human engineering4 have been shown to shape delta evolution. The effects of factors such as sediment type and the overall amount of sediment carried by rivers are considered secondary4,5,6. In particular, the role of sediment cohesion, which is controlled by sediment size and type of vegetation, is unclear. Here we use a numerical flow and transport model7,8,9,10 to show that sediment cohesiveness also strongly influences the morphology of deltas. We find that, holding all other factors constant, highly cohesive sediments form bird’s-foot deltas with rugose shorelines and highly complex floodplains, whereas less cohesive sediments result in fan-like deltas with smooth shorelines and flat floodplains. In our simulations, sediment cohesiveness also controls the number of channels that form within the deltas, and the average angle of bifurcation of those channels. As vegetation generally acts as a cohesive agent, we suggest that deltas that formed before the expansion of land plants in the Devonian period should show fan-like characteristics, a finding consistent with the limited data from the sedimentological record11.

Significant effect of sediment cohesion on delta morphology

The Rio de la Plata waters form a low salinity tongue that affects the circulation, stratification and the distributions of nutrients and biological species over a wide extent of the adjacent continental shelf. The plume of coastal waters presents a seasonal meridional displacement reaching lower latitudes (28°S) during austral winter and 32°S during summer. Historical data suggests that the wind causes the alongshore shift, with southwesterly (SW) winds forcing the plume to lower latitudes in winter while summer dominant northeasterly (NE) winds force its southward retreat. To establish the connection between wind and outflow variations on the distribution of the coastal waters, we conducted two quasi-synoptic surveys in the region of Plata influence on the continental shelf and slope of southeastern South America, between Mar del Plata, Argentina and the northern coast of Santa Catarina, Brazil. We observed that: (A) SW winds dominating in winter force the northward spreading of the plume to low latitudes even during low river discharge periods; (B) NE winds displace the plume southward and spread the low salinity waters offshore over the entire width of the continental shelf east of the Plata estuary. The southward retreat of the plume in summer leads to a volume decrease of low salinity waters over the shelf. This volume is compensated by an increase of Tropical waters, which dominate the northern shelf. The subsurface transition between Subantarctic and Subtropical Shelf Waters, the Subtropical Shelf Front, and the subsurface water mass distribution, however, present minor seasonal variations. Along shore winds also influence the dynamics and water mass variations along the continental shelf area. In areas under the influence of river discharge, Subtropical Shelf Waters are kept away from the coastal region. When low salinity waters retreat southward, NE winds induce a coastal upwelling system near Santa Marta Cape. In summer, solar radiation promotes the establishment of a strong thermocline that increases buoyancy and further enhances the offshore displacement of low salinity waters under the action of NE winds.

The effects of river discharge and seasonal winds on the shelf off southeastern South America

electromagnetic simulation using the fdtd method is available in our book collection an online access to it is set as public so you can download it instantly. Our digital library hosts in multiple locations, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the electromagnetic simulation using the fdtd method is universally compatible with any devices to read.

Electromagnetic Simulation Using The Fdtd Method

Ocean surface roughness plays an important role in air–sea interaction and ocean remote sensing. Its primary contribution is from surface waves much shorter than the energetic wave components near the peak of the wave energy spectrum. Field measurements of short-scale waves are scarce. In contrast, microwave remote sensing has produced a large volume of data useful for short-wave investigation. Particularly, Bragg resonance is the primary mechanism of radar backscatter from the ocean surface and the radar serves as a spectrometer of short surface waves. The roughness spectra inverted from radar backscatter measurements expand the short-wave database to high wind conditions in which in situ sensors do not function well. Using scatterometer geophysical model functions for L-, C-, and Ku-band microwave frequencies, the inverted roughness spectra, covering Bragg resonance wavelengths from 0.012 to 0.20 m, show a convergent trend in high winds. This convergent trend is incorporated in the surface rough...

Ocean Surface Roughness Spectrum in High Wind Condition for Microwave Backscatter and Emission Computations

Patos Lagoon outflow within the Río de la Plata plume using an airborne salinity mapper: Observing an embedded plume ☆

[1] Numerical simulations of the Adriatic Sea were performed with the Navy Coastal Ocean Model (NCOM) during the Dynamics of the Adriatic in Real Time (DART) Experiments conducted between October 2005 and September 2006. Grid resolution was 1 km. Model forcing included tides, surface fluxes from the Aire Limitee Adaptation Dynamique Developpement International (ALADIN) atmospheric model, relaxation to a daily satellite sea surface temperature analysis, extensive river and runoff discharges, and open boundary conditions south of Otranto specified from a global model. Currents predicted by the model were compared with currents from 12 Acoustic Doppler Current Profiler (ADCP) moorings located along a line between the Gargano Peninsula, Italy, and Split, Croatia. The nontidal comparisons were performed with detided currents. Correlations between the model and ADCP currents were highest in the Western Adriatic Current (WAC), which flows southeastward along the Italian coast. Lowest correlations were in the interior of the Adriatic, likely because of instability processes. Correlations between the ALADIN winds and the model and ADCP currents at the mooring locations were also highest in the WAC. For November 2005 through August 2006, the model and ADCP mean WAC transports were 0.321 and 0.304 Sv, respectively, with a temporal correlation of 0.79. Comparison of current variance showed best agreement near the Italian and Croatian coasts. In the interior, the NCOM current variance compared fairly well with that of the ADCPs for November–January but decreased significantly relative to the ADCPs for February–August. Spectral analyses indicate most of the difference in variance to be at periods exceeding 2 days.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2008JC004842

Comparison of Model-Simulated and Observed Currents in the Central Adriatic During DART

The Global Navigation Satellite System (GNSS) signals are always available, globally, and the signal structures are well known, except for those dedicated to military use. They also have some distinctive characteristics, including the use of L-band frequencies, which are particularly suited for remote sensing purposes. The idea of using GNSS signals for remote sensing - the atmosphere, oceans or Earth surface - was first proposed more than two decades ago. Since then, GNSS remote sensing has been intensively investigated in terms of proof of concept studies, signal processing methodologies, theory and algorithm development, and various satellite-borne, airborne and ground-based experiments. It has been demonstrated that GNSS remote sensing can be used as an alternative passive remote sensing technology. Space agencies such as NASA, NOAA, EUMETSAT and ESA have already funded, or will fund in the future, a number of projects/missions which focus on a variety of GNSS remote sensing applications. It is envisaged that GNSS remote sensing can be either exploited to perform remote sensing tasks on an independent basis or combined with other techniques to address more complex applications. This paper provides an overview of the state of the art of this relatively new and, in some respects, underutilised remote sensing technique. Also addressed are relevant challenging issues associated with GNSS remote sensing services and the performance enhancement of GNSS remote sensing to accurately and reliably retrieve a range of geophysical parameters.

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Derek Burrage

Papers

Ocean Surface Roughness Spectrum in High Wind Condition for Microwave Backscatter and Emission Computations

Patos Lagoon outflow within the Río de la Plata plume using an airborne salinity mapper: Observing an embedded plume ☆

Comparison of Model-Simulated and Observed Currents in the Central Adriatic During DART

An overview of GNSS remote sensing

Eddies and filaments of the Western Adriatic Current near Cape Gargano: Analysis and prediction