scholarly journals Novel metrics based on Biogeochemical Argo data to improve the model uncertainty evaluation of the CMEMS Mediterranean marine ecosystem forecasts

Ocean Science ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 997-1022 ◽  
Author(s):  
Stefano Salon ◽  
Gianpiero Cossarini ◽  
Giorgio Bolzon ◽  
Laura Feudale ◽  
Paolo Lazzari ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Reference Data ◽  
Robust Statistics ◽  
Marine Ecosystem ◽  
Global Ocean ◽  
Argo Data ◽  
Argo Floats ◽  
Biogeochemical Models ◽  
The Mediterranean

Abstract. The quality of the upgraded version of the Copernicus Marine Environment Monitoring Service (CMEMS) biogeochemical operational system of the Mediterranean Sea (MedBFM) is assessed in terms of consistency and forecast skill, following a mixed validation protocol that exploits different reference data from satellite, oceanographic databases, Biogeochemical Argo floats, and literature. We show that the quality of the MedBFM system has been improved in the previous 10 years. We demonstrate that a set of metrics based on the GODAE (Global Ocean Data Assimilation Experiment) paradigm can be efficiently applied to validate an operational model system for biogeochemical and ecosystem forecasts. The accuracy of the CMEMS biogeochemical products for the Mediterranean Sea can be achieved from basin-wide and seasonal scales to mesoscale and weekly scales, and its level depends on the specific variable and the availability of reference data, the latter being an important prerequisite to build robust statistics. In particular, the use of the Biogeochemical Argo floats data proved to significantly enhance the validation framework of operational biogeochemical models. New skill metrics, aimed to assess key biogeochemical processes and dynamics (e.g. deep chlorophyll maximum depth, nitracline depth), can be easily implemented to routinely monitor the quality of the products and highlight possible anomalies through the comparison of near-real-time (NRT) forecasts skill with pre-operationally defined seasonal benchmarks. Feedbacks to the observing autonomous systems in terms of quality control and deployment strategy are also discussed.

scholarly journals Marine Ecosystem forecasts: skill performance of the CMEMS Mediterranean Sea model system

2019 ◽  
Author(s):  
Stefano Salon ◽  
Gianpiero Cossarini ◽  
Giorgio Bolzon ◽  
Laura Feudale ◽  
Paolo Lazzari ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Reference Data ◽  
Marine Ecosystem ◽  
Model System ◽  
Operational Model ◽  
Argo Floats ◽  
Biogeochemical Models ◽  
Validation Framework ◽  
Skill Performance

Abstract. The quality of the upgraded version of the CMEMS biogeochemical operational system of the Mediterranean Sea (MedBFM) is assessed in terms of consistency and forecast skill, following a mixed validation protocol that exploits different reference data from satellite, oceanographic databases, Biogeochemical Argo floats, literature. We demonstrate that the GODAE metrics paradigm can be efficiently applied to validate an operational model system for biogeochemical and ecosystem forecasts. The accuracy of the CMEMS biogeochemical products for Mediterranean Sea can be achieved from basin-wide and seasonal scale to mesoscale and weekly scale, and its level depends on the specific variable and the availability of reference data. In particular, the use of the Biogeochemical Argo floats data allows for a relevant enhancement of the validation framework of operational biogeochemical models, providing new skill metrics for key biogeochemical processes and dynamics (e.g. deep chlorophyll maximum depth), which can be easily implemented to routinely monitor the quality of the products and highlight any possible anomaly.

scholarly journals XBT, ARGO Float and Ship-Based CTD Profiles Intercompared under Strict Space-Time Conditions in the Mediterranean Sea: Assessment of Metrological Comparability

2020 ◽  
Vol 8 (5) ◽  
pp. 313
Author(s):  
Andrea Bordone ◽  
Francesca Pennecchi ◽  
Giancarlo Raiteri ◽  
Luca Repetti ◽  
Franco Reseghetti
Keyword(s):  
Mediterranean Sea ◽  
Space Time ◽  
Ocean Dynamics ◽  
Experimental Comparison ◽  
Argo Data ◽  
Argo Floats ◽  
Depth Sensors ◽  
Space And Time ◽  
Post Process ◽  
The Mediterranean

Accurate measurement of temperature and salinity is a fundamental task with heavy implications in all the possible applications of the currently available datasets, for example, in the study of climate changes and modeling of ocean dynamics. In this work, the reliability of measurements obtained by oceanographic devices (eXpendable BathyThermographs, Argo floats and Conductivity-Temperature-Depth sensors) is analyzed by means of an intercomparison exercise. As a first step, temperature profiles from XBT probes, deployed by commercial ships crossing the Ligurian and Tyrrhenian seas during the Ship of Opportunity Program (SOOP), were matched with profiles from Argo floats quasi-collocated in space and time. Attention was then paid to temperature/salinity profiling Argo floats. Since Argo floats usually are not recovered and should last up to five years without any re-calibration, their onboard sensors may suffer some drift and/or offset. In the literature, refined methods were developed to post-process Argo data, in order to correct the response of their profiling CTD sensors, in particular adjusting the salinity drift. The core of this delayed-mode quality control is the comparison of Argo data with reference climatology. At the same time, the experimental comparison of Argo profiles with ship-based CTD profiles, matched in space and time, is still of great importance. Therefore, an overall comparison of Argo floats vs. shipboard CTDs was performed, in terms of temperature and salinity profiles in the whole Mediterranean Sea, under space-time matching conditions as strict as possible. Performed analyses provided interesting results. XBT profiles confirmed that below 100 m depth the accordance with Argo data is reasonably good, with a small positive bias (close to 0.05 °C) and a standard deviation equal to about 0.10 °C. Similarly, side-by-side comparisons vs. CTD profiles confirmed the good quality of Argo measurements; the evidence of a drift in time was found, but at a level of about E−05 unit/day, so being reasonably negligible on the Argo time-scale. XBT, Argo and CTD users are therefore encouraged to take into account these results as a good indicator of the uncertainties associated with such devices in the Mediterranean Sea, for the analyzed period, in all the climatological applications.

scholarly journals Gymnorhynchus gigas in Lepidopus caudatus (Actinopterygii: Perciformes: Trichiuridae): prevalence and related effects on fish quality

2014 ◽  
Vol 32 (No. 4) ◽  
pp. 320-325 ◽  
Author(s):  
F. Giarratana ◽  
D. Muscolino ◽  
Ch. Beninati ◽  
G. Ziino ◽  
A. Giuffrida ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Total Volatile ◽  
Fish Quality ◽  
Total Volatile Basic Nitrogen ◽  
Basic Nitrogen ◽  
Hygienic Quality ◽  
High Prevalence ◽  
The Mediterranean

We evaluated the effects of Gymnorhynchus gigas on the freshness and hygienic quality of Lepidopus caudatus. Total Volatile Basic Nitrogen (TVB-N), Trimethylamine Nitrogen (TMA-N), as well as Specific Spoilage Organisms (SSOs) are the most important freshness indicators in fish. Our study was carried-out on 65 specimens of L. caudatus kept in ice and stored at 2°C for different period of time. The microbiological charge of SSOs recovered on a portion of parasitised muscles (MP) was compared with those recovered on portions of parasite-free muscles (M). The contents of TVB-N and TMA-N on MP, M, and G. gigas larva/ae were measured using the Conway microdiffusion method. High prevalence (72.31%) of G. gigas in the specimens of L. caudatus from the Mediterranean sea was observed. No statistically significant differences (P < 0.05) between M and MP were found during storage. However, massive infestation of G. gigas on the muscle of the silver scabbardfish could negatively influence TVB-N values, without compromising the sensorial characteristic of fish.

scholarly journals A high-resolution free-surface model of the Mediterranean Sea

Ocean Science ◽  
2008 ◽  
Vol 4 (1) ◽  
pp. 1-14 ◽  
Author(s):  
M. Tonani ◽  
N. Pinardi ◽  
S. Dobricic ◽  
I. Pujol ◽  
C. Fratianni
Keyword(s):  
Free Surface ◽  
Mediterranean Sea ◽  
General Circulation ◽  
Forecast Model ◽  
Surface Model ◽  
Argo Data ◽  
Basic Model ◽  
Basin Scale ◽  
Before And After ◽  
The Mediterranean

Abstract. This study describes a new model implementation for the Mediterranean Sea with what is currently the highest vertical resolution over the Mediterranean basin. The resolution is of 1/16°×1/16° in the horizontal and has 72 unevenly spaced vertical levels. This model has been developed in the frame of the EU-MFSTEP project and is the operational forecast model currently used at the basin scale. The model considers an implicit free surface and this characteristic enhances the model's capability to simulate the sea surface height variability and the net transport at the Strait of Gibraltar. In this study we show the calibration/validation experiments performed before and after the model was used for forecasting. The first experiment consists of a six-year simulation forced by a perpetual year forcing, and the other experiment is a simulation from January 1997 to December 2004, forcing the model with 6-h atmospheric forcing fields from ECMWF. The model Sea Level Anomaly has been compared for the first time with satellite SLA and with ARGO data to provide evidence of the quality of the simulation. The results show that this model is capable of reproducing most of the variability of the general circulation in the Mediterranean Sea. However, some basic model inadequacies stand out and should be corrected in the near future.

Trends in productivity and biomass yields in the Mediterranean Sea Large Marine Ecosystem during climate change

2016 ◽  
Vol 17 ◽  
pp. 57-74 ◽  
Author(s):  
Konstantinos I. Stergiou ◽  
Stylianos Somarakis ◽  
George Triantafyllou ◽  
Kostas P. Tsiaras ◽  
Marianna Giannoulaki ◽  
...  
Keyword(s):  
Climate Change ◽  
Mediterranean Sea ◽  
Marine Ecosystem ◽  
Biomass Yields ◽  
Large Marine Ecosystem ◽  
The Mediterranean

Oil Pollution in the Mediterranean Sea: An Overview

2020 ◽  
Author(s):  
Angela Carpenter
Keyword(s):  
Mediterranean Sea ◽  
Marine Environment ◽  
Oil Pollution ◽  
Marine Ecosystem ◽  
General Terms ◽  
The Mediterranean ◽  
Many Sources

<p><span>Oil pollution can enter the marine environment from many sources including land, shipping, and oil installations. It can have significant impacts on the marine environment that, depending on the type of oil, can last for prolonged periods of time. Monitoring oil pollution in the Mediterranean Sea region has been conducted using both aerial and satellite surveillance. This presentation will provide an overview of the sources and volumes of oil entering the Mediterranean, identify impacts on the marine ecosystem in general terms, and will review surveillance activities in the region, including cooperative activities undertaken by regional and EU agencies, for example. </span></p> <p> </p>

Vanadium behaviour in the global ocean and in the Mediterranean sea

1987 ◽  
Vol 21 (1) ◽  
pp. 51-74 ◽  
Author(s):  
C Jeandel ◽  
M Caisso ◽  
J.F Minster
Keyword(s):  
Mediterranean Sea ◽  
Global Ocean ◽  
The Mediterranean

scholarly journals On the mesoscale monitoring capability of Argo floats in the Mediterranean Sea

2016 ◽  
Author(s):  
Antonio Sánchez-Román ◽  
Simón Ruiz ◽  
Ananda Pascual ◽  
Baptiste Mourre ◽  
Stéphanie Guinehut
Keyword(s):  
Mediterranean Sea ◽  
Large Scale ◽  
Spatial Scales ◽  
Altimeter Data ◽  
Simulation Experiments ◽  
Argo Data ◽  
Sea Level Anomalies ◽  
The Mediterranean ◽  
Observing System Simulation Experiment ◽  
Initial Objective

Abstract. In this work an Observing System Simulation Experiment (OSSE) approach is used to investigate the Argo array spatial sampling necessary in the Mediterranean Sea to recover the mesoscale signal as seen by altimetry. The monitoring of the mesoscale features is not an initial objective of the Argo network. However, it is an interesting question in the perspective of future network extensions in order to improve the ocean state estimates. A quality assessment of the performances of the altimeter product is carried out to quantify the differences between Argo and altimetry needed to conduct the simulation experiments. The method used here to evaluate the altimeter data is based on the comparison of Sea Level Anomalies (SLA) from altimetry and Dynamic Height Anomalies (DHA) referred to both 400 and 900 dbar computed from the in-situ Argo network. A standard deviation of the differences between SLA and DHA of 4.92 cm is obtained when comparing altimetry and Argo data referred to 400 dbar. The simulation experiments show that a configuration similar to the current Argo array in the Mediterranean (with a spatial resolution of 2° × 2°) is only able to recover the large-scale signals of the basin. On the contrary, the SLA field reconstructed from a 0.75° x 0.75° Argo network can retrieve most of the mesoscale signal. Such an Argo array of around 450 floats in the Mediterranean Sea would be enough to recover the SLA field with an RMSE of 3 cm for spatial scales higher than 150 km, similar to those captured by the altimetry.

scholarly journals Bridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the ocean

2021 ◽  
Author(s):  
Martí Galí ◽  
Marcus Falls ◽  
Hervé Claustre ◽  
Olivier Aumont ◽  
Raffaele Bernardello
Keyword(s):  
Organic Carbon ◽  
Particulate Organic Carbon ◽  
Optical Data ◽  
Model Parameters ◽  
Turnover Rates ◽  
Argo Data ◽  
Dynamic Component ◽  
Argo Floats ◽  
Biogeochemical Models ◽  
Sinking Particles

Abstract. Oceanic particulate organic carbon (POC) is a relatively small (~4 Pg C) but dynamic component of the global carbon cycle with fast mean turnover rates compared to other oceanic, continental and atmospheric carbon stocks. Biogeochemical models historically focused on reproducing the sinking flux of POC driven by large fast-sinking particles (bPOC). However, suspended and slow-sinking particles (sPOC) typically represent 80–90 % of the POC stock, and can make important seasonal contributions to vertical fluxes through the mesopelagic layer (200–1000 m). Recent developments in the parameterization of POC reactivity in the PISCES model (PISCESv2_RC) have greatly improved its ability to capture sPOC dynamics. Here we evaluated this model by matching 3D and 1D simulations with BGC-Argo and satellite observations in globally representative ocean biomes, building on a refined scheme for converting particulate backscattering profiles measured by BGC-Argo floats to POC. We show that PISCES captures the major features of sPOC and bPOC as seen by BGC-Argo floats across a range of spatiotemporal scales, from highly resolved profile time series to biome-aggregated climatological profiles. Our results also illustrate how the comparison between the model and observations is hampered by (1) the uncertainties in empirical POC estimation, (2) the imperfect correspondence between modelled and observed variables, and (3) the bias between modelled and observed physics. Despite these limitations, we identified characteristic patterns of model-observations misfits in the mesopelagic layer of subpolar and subtropical gyres. These misfits likely result from both suboptimal model parameters and model equations themselves, pointing to the need to improve the model representation of processes with a critical influence on POC dynamics, such as sinking, remineralization, (dis)aggregation and zooplankton activity. Beyond model evaluation results, our analysis identified inconsistencies between current estimates of POC from satellite and BGC-Argo data, as well as POC partitioning into phytoplankton, heterotrophs and detritus deduced from in situ bio-optical data. Our approach can help constrain POC stocks, and ultimately budgets, in the epipelagic and mesopelagic ocean.

scholarly journals Distributions of the carbonate system properties, anthropogenic CO<sub>2</sub>, and acidification during the 2008 BOUM cruise (Mediterranean Sea)

2012 ◽  
Vol 9 (3) ◽  
pp. 2709-2753 ◽  
Author(s):  
F. Touratier ◽  
V. Guglielmi ◽  
C. Goyet ◽  
L. Prieur ◽  
M. Pujo-Pay ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Dissolved Inorganic Carbon ◽  
Marine Ecosystem ◽  
Total Alkalinity ◽  
Carbonate System ◽  
Simple Method ◽  
Deep Waters ◽  
History Of ◽  
The Mediterranean ◽  
System Properties

Abstract. We relate here the distributions of two carbonate system key properties (total alkalinity, AT; and total dissolved inorganic carbon, CT) measured along a section in the Mediterranean Sea, going from Marseille (France) to the south of the Cyprus Island, during the 2008 BOUM cruise. The three main objectives of the present study are (1) to draw and comment on the distributions of AT and CT in the light of others properties like salinity, temperature, and dissolved oxygen, (2) to estimate the distribution of the anthropogenic CO2 (CANT) in the intermediate and the deep waters, and (3) to calculate the resulting variation of pH (acidification) since the beginning of the industrial era. Since the calculation of CANT is always an intense subject of debate, we apply two radically different approaches to estimate CANT: the very simple method TrOCA and the MIX approach, the latter being more precise but also more difficult to apply. A clear picture for the AT and the CT distributions is obtained: the mean concentration of AT is higher in the oriental basin while that of CT is higher in the occidental basin of the Mediterranean Sea, fully coherent with the previous published works. Despite of the two very different approaches we use here (TrOCA and MIX), the estimated distributions of CANT are very similar. These distributions show that the minimum of CANT encountered during the BOUM cruise is higher than 46.3 μmol kg−1 (TrOCA) or 48.8 μmol kg−1(MIX). All Mediterranean water masses (even the deepest) appear to be highly contaminated by CANT, as a result of the very intense advective processes that characterize the recent history of the Mediterranean circulation. As a consequence, unprecedented levels of acidification are reached with an estimated decrease of pH since the pre-industrial era of −0.148 to −0.061 pH unit, which places the Mediterranean Sea as one of the most acidified world marine ecosystem.

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