Consulta: creatorFacets:"Rivier, Aurelie"
Registros recuperados: 6
Data/hora: 26/07/2024 22:47:20

Construction of Multi-Year Time-Series Profiles of Suspended Particulate Inorganic Matter Concentrations Using Machine Learning Approach
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Renosh, Pannimpullath R.; Jourdin, Frederic; Charantonis, Anastase A.; Yala, Khalil; Rivier, Aurelie; Badran, Fouad; Thiria, Sylvie; Guillou, Nicolas; Leckler, Fabien; Gohin, Francis; Garlan, Thierry.
Hydro-sedimentary numerical models have been widely employed to derive suspended particulate matter (SPM) concentrations in coastal and estuarine waters. These hydro-sedimentary models are computationally and technically expensive in nature. Here we have used a computationally less-expensive, well-established methodology of self-organizing maps (SOMs) along with a hidden Markov model (HMM) to derive profiles of suspended particulate inorganic matter (SPIM). The concept of the proposed work is to benefit from all available data sets through the use of fusion methods and machine learning approaches that are able to process a growing amount of available data. This approach is applied to two different data sets entitled “Hidden” and “Observable”. The hidden...
Tipo: Text
Palavras-chave: Suspended particulate inorganic matter; Self-organizing maps; Hidden Markov Model; Machine learning; English Channel; ROMS.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00415/52653/53511.pdf

Dynamique des matières en suspensions minérales des eaux de surface de la Manche observée par satellite et modélisée numériquement.
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rivier, Aurelie.
Study of mineral suspended particulate matter (SPM) is essential to understand ecosystem dynamics. SPM influences light penetration which is closely related to primary production and carries pollutants and nutrients within the water masses. This work aims to study near-surface mineral SPM dynamics in the English Channel using two complementary methods: remote-sensing by satellites and numerical modelling. Firstly, MODIS and MERIS satellite images processed by the IFREMER semi-analytical algorithm and describing non-algal SPM, are analysed to build three statistical models which are able to estimate near-surface SPM using simple variables, e.g., tidal coefficient, significant wave height and mean chlorophyll-a concentration. Secondly, the three-dimensional...
Tipo: Text
Palavras-chave: Matière en suspension; Télédétection; Satellite; Modélisation; Manche; Sédiments; Turbidité; Marée; Houle; Suspended particulate matter; Satellite; Remote-sensing; Modelling; English Channel; Sediments; Turbidity; Tide; Wave.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26783/24884.pdf

Modeling and satellite remote-sensing of near-surface non-algal suspended particulate matter in the English Channel
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rivier, Aurelie; Guillou, Nicolas; Chapalain, Georges; Gohin, Francis.
Concentration of near-surface suspended particulate matter (SPM) is a key parameter for the characterization of sediment dynamics and the quantification of light in the water column for hydrological and biological modeling in coastal seas. The influences of tides and wind-generated surface-gravity waves on non-algal near-surface SPM in the English Channel have recently been identified by Rivier et al. (2012) on the basis of statistical models applied to a large satellite dataset. The present study extends this analysis by comparing satellite images and numerical model predictions of non-algal near-surface SPM. Satellite images are MODIS and MERIS remote-sensing reflectance processed by the IFREMER semi-analytical algorithm (Gohin et al., 2011). These data...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00108/21959/19553.pdf

Modeling Near-Surface Suspended Sediment Concentration in the English Channel
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Guillou, Nicolas; Rivier, Aurelie; Gohin, Francis; Chapalain, Georges.
The present study investigates the performances of the three-dimensional multicomponent hydro-sedimentary model ROMS (Regional Ocean Modeling System) to predict near-surface suspended sediment concentrations (SSC) in the English Channel (western Europe). Predictions are assessed against satellite-retrieved observations from raw MODIS and MERIS images for the year 2008 characterized by the highest availability of cloud-free data. Focus is put on improvements obtained with: (1) SSC inputs at the open boundaries; and (2) simple parameterizations of the settling velocity and the critical shear stress. Sensitivity studies confirm the importance of the advection of fine-grained suspended sediments in the central waters of the English Channel exhibiting benefits...
Tipo: Text
Palavras-chave: ROMS; Satellite; MERIS; MODIS; Tide; Wave.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00276/38766/37307.pdf

Observed vs. predicted variability in non-algal suspended particulate matter concentration in the English Channel in relation to tides and waves
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rivier, Aurelie; Gohin, Francis; Bryere, Philippe; Petus, Caroline; Guillou, Nicolas; Chapalain, Georges.
The study of water clarity is essential to understand variability in biological production, particularly in coastal seas. The spatial and temporal variability of non-algal suspended particulate matter (SPM) in surface waters of the English Channel was investigated and related to local forcing by means of a large satellite dataset covering the study area with a spatial resolution of 1.2 km and a daily temporal resolution. This analysed dataset is a time series of non-algal SPM images derived from MODIS and MERIS remote-sensing reflectance by application of an IFREMER semi-analytical algorithm over the period 2003–2009. In a first step, the variability of time series of MODIS images was analysed through temporal autocorrelation functions. Then, non-algal SPM...
Tipo: Text
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00064/17546/15139.pdf

The impact of tides and waves on near-surface suspended sediment concentrations in the English Channel
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Guillou, Nicolas; Rivier, Aurelie; Chapalain, Georges; Gohin, Francis.
Numerous ecological problems of continental shelf ecosystems require a refined knowledge of the evolution of suspended sediment concentrations (SSC). The present investigation focuses on the spatial and temporal variabilities of near-surface SSC in coastal waters of the English Channel (western Europe) by exploiting numerical predictions from the Regional Ocean Modeling System ROMS. Extending previous investigations of ROMS performances in the Channel, this analysis refines, with increased spatial and temporal resolutions, the characterization of near-surface SSC patterns revealing areas where concentrations are highly correlated with evolutions of tides and waves. Significant tidal modulations of near-surface concentrations are thus found in the eastern...
Tipo: Text
Palavras-chave: Sediment transport; Numerical modeling; Satellite; ROMS; MERIS; MODIS.
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00345/45607/45227.pdf