scholarly journals The Mediterranean Ocean Colour Level 3 Operational Multi-Sensor Processing

2018 ◽  
Author(s):  
Gianluca Volpe ◽  
Simone Colella ◽  
Vittorio Brando ◽  
Vega Forneris ◽  
Flavio La Padula ◽  
...  
Keyword(s):  
Fine Tuning ◽  
Ocean Colour ◽  
Basin Scale ◽  
Sensor Processing ◽  
Level 3 ◽  
The Mediterranean ◽  
Set Up ◽  
Marine Environment Monitoring ◽  
Monitoring Service

Abstract. This work describes the main processing steps operationally performed to enable single ocean colour sensors to enter the multi-sensor chain for the Mediterranean Sea of Ocean Colour Thematic Assembling Centre. Here, the multi-sensor chain takes care of reducing the inter-sensor bias before data from different sensors are merged together. The basin-scale in situ bio-optical dataset is used both to fine-tuning the algorithms for the retrieval of phytoplankton chlorophyll and attenuation coefficient of light, Kd, and to assess the uncertainty associated with them. The satellite multi-sensor remote sensing Reflectance spectra better agree with the in situ observations than that of the single sensors, and are comparable with the ESA-OC-CCI multi-sensor product, highlighting the importance of reducing the inter-sensor bias. The Mediterranean near-real-time multi-sensor processing chain has been set up and is operational in the framework of the Copernicus Marine Environment Monitoring Service.

scholarly journals Mediterranean ocean colour Level 3 operational multi-sensor processing

Ocean Science ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 127-146 ◽  
Author(s):  
Gianluca Volpe ◽  
Simone Colella ◽  
Vittorio E. Brando ◽  
Vega Forneris ◽  
Flavio La Padula ◽  
...  
Keyword(s):  
Ocean Colour ◽  
Full Data ◽  
Processing Chain ◽  
Basin Scale ◽  
Sensor Processing ◽  
Level 3 ◽  
The Mediterranean ◽  
Set Up ◽  
Marine Environment Monitoring

Abstract. The Mediterranean near-real-time multi-sensor processing chain has been set up and is operational in the framework of the Copernicus Marine Environment Monitoring Service (CMEMS). This work describes the main steps operationally performed to enable single ocean colour sensors to enter the multi-sensor processing applied to the Mediterranean Sea by the Ocean Colour Thematic Assembly Centre within CMEMS. Here, the multi-sensor chain takes care of reducing the inter-sensor bias before data from different sensors are merged together. A basin-scale in situ bio-optical dataset is used both to fine tune the algorithms for the retrieval of phytoplankton chlorophyll and the attenuation coefficient of light, Kd, and to assess the uncertainty associated with them. The satellite multi-sensor remote sensing reflectance spectra agree better with the in situ observations than those of the single sensors. Here, we demonstrate that the operational multi-sensor processing chain compares sufficiently well with the historical in situ datasets to also confidently be used for reprocessing the full data time series.

scholarly journals Supplementary material to "The Mediterranean Ocean Colour Level 3 Operational Multi-Sensor Processing"

2018 ◽  
Author(s):  
Gianluca Volpe ◽  
Simone Colella ◽  
Vittorio Brando ◽  
Vega Forneris ◽  
Flavio La Padula ◽  
...  
Keyword(s):  
Ocean Colour ◽  
Sensor Processing ◽  
Level 3 ◽  
Supplementary Material ◽  
The Mediterranean

scholarly journals Implementation and validation of a new operational wave forecasting system of the Mediterranean Monitoring and Forecasting Centre in the framework of the Copernicus Marine Environment Monitoring Service

2018 ◽  
Vol 18 (10) ◽  
pp. 2675-2695 ◽  
Author(s):  
Michalis Ravdas ◽  
Anna Zacharioudaki ◽  
Gerasimos Korres
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Model Performance ◽  
Environment Monitoring ◽  
Marine Research ◽  
Forecasting System ◽  
The Mediterranean ◽  
Marine Environment Monitoring ◽  
Monitoring Service ◽  
Wave Forecasting

Abstract. Within the framework of the Copernicus Marine Environment Monitoring Service (CMEMS), an operational wave forecasting system for the Mediterranean Sea has been implemented by the Hellenic Centre for Marine Research (HCMR) and evaluated through a series of preoperational tests and subsequently for 1 full year of simulations (2014). The system is based on the WAM model and it has been developed as a nested sequence of two computational grids to ensure that occasional remote swell propagating from the North Atlantic correctly enters the Mediterranean Sea through the Strait of Gibraltar. The Mediterranean model has a grid spacing of 1∕24∘. It is driven with 6-hourly analysis and 5-day forecast 10 m ECMWF winds. It accounts for shoaling and refraction due to bathymetry and surface currents, which are provided in offline mode by CMEMS. Extensive statistics on the system performance have been calculated by comparing model results with in situ and satellite observations. Overall, the significant wave height is accurately simulated by the model while less accurate but reasonably good results are obtained for the mean wave period. In both cases, the model performs optimally at offshore wave buoy locations and well-exposed Mediterranean subregions. Within enclosed basins and near the coast, unresolved topography by the wind and wave models and fetch limitations cause the wave model performance to deteriorate. Model performance is better in winter when the wave conditions are well defined. On the whole, the new forecast system provides reliable forecasts. Future improvements include data assimilation and higher-resolution wind forcing.

First release of the CMEMS Global coastal OLCI 300 meters Chlorophyll-a Product

2021 ◽  
Author(s):  
Philippe Garnesson ◽  
Antoine Mangin ◽  
Julien Demaria ◽  
Marine Bretagnon ◽  
Odile Hembise Fanton d'Andon
Keyword(s):  
Chlorophyll A ◽  
Spatial Resolution ◽  
End User ◽  
Vicarious Calibration ◽  
Large Matrix ◽  
Merging Procedure ◽  
Level 3 ◽  
Marine Environment Monitoring ◽  
Monitoring Service ◽  
Level 2

<p>The Ocean Colour Instrument (OLCI) on-board the Sentinel-3A and 3B satellites with a 300 m spatial resolution has a major advantage compared to other satellite missions with a typical 1 km spatial resolution. The chlorophyll-a product derived from OLCI’s 300 m measurement facilitates many applications in marine and coastal ecology, from ecosystem modeling, to fisheries management, and monitoring of water quality. The OLCI 300 m chlorophyll-a swath data (Level-2) are operationally disseminated in NRT mode by the EUMETSAT agency. The Copernicus Marine Environment Monitoring Service (CMEMS) eases the usage of these Level-2 (swath data) by providing Level-3 (daily mapped gridded files) at global and regional level.</p><p>This study highlights the first release of a 300 m NRT global daily chlorophyll-a product based on the merging of OLCI S3A and S3B. It will be routinely disseminated in the frame of CMEMS in May 2021. Before this date, the resolution of the CMEMS Chlorophyll products was 4km at global level and 1km over some European regional seas This 300 m product will be based on the Copernicus-GlobColour processor already used by CMEMS for the Global chlorophyll-a product and the regional Atlantic daily interpolated product. The daily image will correspond to a large matrix of 32400x64800 pixels with chlorophyll-a data provided along the coastline (200 km). CMEMS provides to the end-user facilities to extract data on his area and period of interest.</p><p>This new product will take benefit of a new EUMETSAT’s Level-2 product baseline which should be switched operationally in NRT mode mid-February 2021. This new baseline improves mainly the System Vicarious Calibration (SVC) gains of both S3A and S3B and the associated quality flags. The Chlorophyll-a OC4ME algorithm has been also improved with the use of the Colour Index algorithm for clear water. The assessment of this new OC4ME chlorophyll-a product (based on tandem data) shows a very good correlation between S3A and S3B. A regression between a daily S3A and S3B global product provides a R2 of 0.98 with a respective slope and offset of 1.0 and 0.005. However, some limitations concerning the level-2 upstream products have been identified. Details about the merging procedure, inter-comparison with existing product and illustrations of results will be presented.</p>

Evidence of selection for effective nodulation in the Trifolium spp. symbiosis with Rhizobium leguminosarum biovar trifolii

2005 ◽  
Vol 45 (3) ◽  
pp. 189 ◽  
Author(s):  
R. J. Yates ◽  
J. G. Howieson ◽  
D. Real ◽  
W. G. Reeve ◽  
A. Vivas-Marfisi ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
Acid Soil ◽  
Acid Soils ◽  
Nodule Occupancy ◽  
Rhizobium Strains ◽  
Natural Grasslands ◽  
The Mediterranean ◽  
And Performance ◽  
Set Up

The pasture-breeding program to improve production in the natural grasslands in Uruguay has acknowledged that indigenous Rhizobium strains are incompatible with introduced Mediterranean clovers. In an attempt to understand and overcome this problem, a cross-row experiment was set up in 1999 in a basaltic, acid soil in Glencoe, Uruguay, to follow the survival and performance of 9 exotic strains of Rhizobium leguminosarum bv. trifolii. This paper reports on the ability of the introduced strains to compete for nodule occupancy of Mediterranean clover hosts and impacts of the introduced strains on the productivity of the indigenous Uruguayan clover Trifolium polymorphum. Strain WSM1325 was a superior inoculant and remained highly persistent and competitive for the effective symbiosis with the Mediterranean hosts, T. purpureum and T. repens, in the Uruguayan environment in the third year of the experiment. The Mediterranean hosts (T. purpureum and T. repens) nodulated with the introduced strains but did not nodulate with any indigenous R. leguminosarum bv. trifolii typed from nodules of T. polymorphum. Conversely, there were no nodules on the Uruguayan host T. polymorphum that contained introduced R. leguminosarum bv. trifolii. These results reveal the establishment of effective symbioses between strains of R. leguminosarum bv. trifolii and clover even though the soil contained ineffective R. leguminosarum bv. trifolii for all hosts. We believe our results are the first reported example of ‘selective’ nodulation for an effective symbiosis in situ with annual and perennial clovers in acid soils.

scholarly journals The Mediterranean Ocean Colour Observing System: system development and product validation

2012 ◽  
Vol 9 (2) ◽  
pp. 1349-1385 ◽  
Author(s):  
G. Volpe ◽  
S. Colella ◽  
V. Forneris ◽  
C. Tronconi ◽  
R. Santoleri
Keyword(s):  
Product Quality ◽  
Real Time ◽  
System Development ◽  
Point Of View ◽  
Ocean Colour ◽  
Time Data ◽  
Uncertainty Sources ◽  
Operational Oceanography ◽  
The Mediterranean

Abstract. This paper presents the Mediterranean Ocean Colour Observing System in the framework of the growing demand of near real time data emerging within the operational oceanography international context. The main issues related with the satellite operational oceanography are tied to (1) the near real-time ability to track data flow uncertainty sources; (2) in case of failure, to provide backup solutions to end-users; and (3) to scientifically assess the product quality. We describe the major scientific and technological steps made to develop, maintain and improve the operational system and its products. A method for assessing the near real-time product quality is developed and its limitation discussed. Main results are concerned with the degradation, starting from mid-2010, of the MODIS Aqua channel at 443 nm. The product validation analysis highlights that SeaWiFS chlorophyll product over the Mediterranean Sea is the best performing in comparison with those of MODIS and MERIS. Despite their general good agreement with in situ observations, MODIS- and MERIS-derived chlorophyll present a slight and systematic underestimation of their in situ counter part. The most relevant implications induced by these results are discussed from an operational point of view.

scholarly journals The MULTI OBSERVATIONS Thematic Assembly Centre of the Copernicus Marine Environment Monitoring Service

2021 ◽  
Author(s):  
Stephanie Guinehut ◽  
Bruno Buongiorno Nardelli ◽  
Trang Chau ◽  
Frederic Chevallier ◽  
Daniele Ciani ◽  
...  
Keyword(s):  
Data Fusion ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Global Ocean ◽  
Environment Monitoring ◽  
Surface Salinity ◽  
In Situ Observations ◽  
Marine Environment Monitoring ◽  
Monitoring Service

<p>Complementary to ocean state estimate provided by modelling/assimilation systems, a multi observations-based approach is available through the MULTI OSERVATIONS (MULTIOBS) Thematic Assembly Center (TAC) of the European Copernicus Marine Environment Monitoring Service (CMEMS).</p><p>CMEMS MULTIOBS TAC proposes products based on satellite & in situ observations and state-of-the-art data fusion techniques. These products are fully qualified and documented and, are distributed through the CMEMS catalogue (http://marine.copernicus.eu/services-portfolio). They cover the global ocean for physical and biogeochemical (BGC) variables. They are available in Near-Real-Time (NRT) or as Multi-Year Products (MYP) for the past 28 to 36 years.</p><p>Satellite input observations include altimetry but also sea surface temperature, sea surface salinity as well as ocean color. In situ observations of physical and BGC variables are from autonomous platform such as Argo, moorings and ship-based measurements. Data fusion techniques are based on multiple linear regression method, multidimensional optimal interpolation method or neural networks.</p><p>MULTIOBS TAC provides the following products at global scale:</p><ul><li>3D temperature, salinity and geostrophic current fields, both in NRT and as MYP;</li> <li>2D sea surface salinity and sea surface density fields, both in NRT and as MYP;</li> <li>2D total surface and near-surface currents, both in NRT and as MYP;</li> <li>3D vertical current as MYP;</li> <li>2D surface carbon fields of CO<sub>2</sub> flux (fgCO<sub>2</sub>), pCO<sub>2</sub> and pH as MYP;</li> <li>Nutrient vertical distribution (including nitrate, phosphate and silicate) profiles as MYP;</li> <li>3D Particulate Organic Carbon (POC) and Chlorophyll-a (Chl-a) fields as MYP.</li> </ul><p>Furthermore, MULTIOBS TAC provides specific Ocean Monitoring Indicators (OMIs), based on the above products, to monitor the global ocean 3D hydrographic variability patterns (water masses) and the global ocean carbon sink.</p>

In Situ TAC Dashboard, an Advanced Tool for visualizing CMEMS In Situ products

2021 ◽  
Author(s):  
Paz Rotllán-García ◽  
Fernando Manzano ◽  
Maria Sotiropoulou ◽  
Keyword(s):  
Product Family ◽  
Spatial Coverage ◽  
Wide Range ◽  
Report Data ◽  
In Situ Observations ◽  
Rest Api ◽  
Marine Environment Monitoring ◽  
Monitoring Service ◽  
User Friendly

<p>The In Situ Thematic Assembly Center (In Situ TAC) for the Copernicus Marine Environment Monitoring Service (CMEMS) is the only data component in the system, out of a total of fifteen, in charge of delivering quality-checked in situ observations in both near real time (NRT products) and delay mode (REP products) for their use in the characterisation of ocean state and variability, assimilation and/or validation activities carried out by the metocean community. </p><p>These in situ observations are gathered by a wide range of platforms (tide gauges, buoys, vessels, CTDs, profilers, gliders, drifters, HF radars, saildrones etc) and include many different parameters (Temperature, Salinity, Sea Level, Currents, Waves, Oxygen, Chlorophyll, Nutrients, Carbon etc). They are made available through known networks and regional data providers to a set of Production Units (PUs) or dedicated Data Centers (Ifremer, PdE, HCMR, IMR, IO-BAS, BSH, SMHI, UiB, CNR, AZTI) where they are quality-checked and homogenized before delivery in terms of format, quality control conventions and standards.</p><p>Unlike most of the products available in the CMEMS catalog (90%), in situ  data products do not naturally provide a regular temporal and spatial coverage or resolution. Indeed, these in situ observations can be available at fixed locations, or on a trajectory, or in a gridded area, at fixed depths or on profiles and the transmitting equipment can be configured to report data in different time samplings. Such a  complexity has traditionally prevented 82% of the In Situ TAC products from fully taking advantage of  CMEMS centralized improvements  in terms of the visualization of datasets (WMS) and subsetting (Subsetter). </p><p>To overcome  this situation, a first version of the CMEMS In Situ TAC Dashboard was released in 2017. This tool provides a user-friendly interface which enables the discovery, subsetting, sharing and downloading of files containing in-situ observations from In Situ TAC multiparameter NRT products. The tool relies on a set of python scripts which process homogenized metadata on an hourly basis as well as complementary information submitted by Sea Data Net (provider overview). The resulting information is then accessible through  the interface with the aid of a json-server REST API, which allows users to make queries and filter the information according to their interest.</p><p>In 2020, the current release of the CMEMS In Situ Dashboard has been officially approved as an “Advanced Visualization Tool” by CMEMS and is now showcased as a complementary tool to the official viewer. Future developments will explore its extension to the whole In Situ product family (beyond the present In Situ multiparameter NRT datasets), the improvement of data visualization options (currently using EMODnet widget services) and the implementation of data discovery capabilities.</p>

scholarly journals The Mediterranean Ocean Colour Observing System – system development and product validation

Ocean Science ◽  
2012 ◽  
Vol 8 (5) ◽  
pp. 869-883 ◽  
Author(s):  
G. Volpe ◽  
S. Colella ◽  
V. Forneris ◽  
C. Tronconi ◽  
R. Santoleri
Keyword(s):  
Product Quality ◽  
Real Time ◽  
System Development ◽  
Point Of View ◽  
Ocean Colour ◽  
Time Data ◽  
Uncertainty Sources ◽  
Operational Oceanography ◽  
The Mediterranean

Abstract. This paper presents the Mediterranean Ocean Colour Observing System in the framework of the growing demand of near real-time data emerging within the operational oceanography international context. The main issues related to the satellite operational oceanography are tied to the following: (1) the near real-time ability to track data flow uncertainty sources; (2) in case of failure, to provide backup solutions to end-users; and (3) to scientifically assess the product quality. We describe the major scientific and technological steps made to develop, maintain and improve the operational system and its products. A method for assessing the near real-time product quality is developed and its limitation discussed. Main results are concerned with the degradation, starting from mid-2010, of the MODIS Aqua channel at 443 nm with its successive recovery thanks to the new calibration scheme implemented in the recently released SeaDAS version 6.4. The product validation analysis highlights that SeaWiFS chlorophyll product over the Mediterranean Sea is the best performing in comparison with those of MODIS and MERIS. Despite their general good agreement with in situ observations, MODIS- and MERIS-derived chlorophyll present a slight and systematic underestimation of the in situ counter part. The most relevant implications induced by these results are discussed from an operational point of view.

scholarly journals Implementation and validation of a new operational wave forecasting system of the Mediterranean Monitoring and Forecasting Centre in the framework of the Copernicus Marine Environment Monitoring Service

2018 ◽  
Author(s):  
Michalis Ravdas ◽  
Anna Zacharioudaki ◽  
Gerasimos Korres
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Model Performance ◽  
Environment Monitoring ◽  
Marine Research ◽  
Forecasting System ◽  
The Mediterranean ◽  
Marine Environment Monitoring ◽  
Monitoring Service ◽  
Wave Forecasting

Abstract. Within the framework of the Copernicus Marine Environment Monitoring Service (CMEMS) an operational wave forecasting system for the Mediterranean Sea has been implemented by the Hellenic Centre for Marine Research (HCMR) and evaluated through a series of pre-operational tests and subsequently for one full year of simulations (2014). The system is based on the WAM model and it has been developed as a nested sequence of two computational grids to ensure that occasional remote swell propagating from the North Atlantic is correctly entering into the Mediterranean Sea through the Gibraltar Strait. The Mediterranean model has a grid spacing of 1/24°. It is driven with 6-hourly analysis and 5-days forecast 10 m ECMWF winds. It accounts for shoaling and refraction due to bathymetry and surface currents which are provided in off-line mode by CMEMS. Extensive statistics on the system performance have been calculated by comparing model results with in-situ and satellite observations. Overall, the significant wave height is accurately simulated by the model while less accurate but reasonably good results are obtained for the mean wave period. In both cases, the model performs optimally at offshore wave buoy locations and well-exposed Mediterranean sub-regions. Within enclosed basins and near the coast, unresolved topography by the wind and wave models and fetch limitations cause the wave model performance to deteriorate. Model performance is better in winter when the wave conditions are well-defined. On the whole, the new forecast system provides reliable forecasts. Future improvements include data assimilation and higher resolution wind forcing.

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