scholarly journals Towards a regional ocean forecasting system for the IBI (Iberia-Biscay-Ireland area): developments and improvements within the ECOOP project framework

2011 ◽  
Vol 8 (5) ◽  
pp. 1937-1977
Author(s):  
S. Cailleau ◽  
J. Chanut ◽  
J.-M. Lellouche ◽  
B. Levier ◽  
C. Maraldi ◽  
...  

Abstract. ECOOP project allowed the improvement of the regional and coastal operational forecasting systems for the different European Seas. In the Iberia-Biscay-Ireland area (IBI) a regional system has been developed and improved for the project in order to provide IBI partners the best initial and boundary conditions to their embedded coastal systems. End users could also get access to the regional hindcasts and forecasts through the ECOOP website. This system has been upgraded as follow: a first existing version V0, a second base-line version V1 ready for the ECOOP Target Operational Period and a third one V2 which consists in a new generation regional system. This paper especially pays attention to the improvements from the V1 system, whose physics are close to a large scale basin system, to the V2 one which physics are more adapted to shelf and coastal issues. Strong developments which allow further regional physics resolution in the NEMO OGCM such as tide, non linear free surface and adapted vertical mixing scheme among other have been carried out from V1 to V2 versions for the project. Thus, regional thermal fronts due to tidal mixing appear in V2 solution and are quite well placed. Moreover, simulation of the stratification in shelf areas is also improved in V2.

Ocean Science ◽  
2012 ◽  
Vol 8 (2) ◽  
pp. 143-159 ◽  
Author(s):  
S. Cailleau ◽  
J. Chanut ◽  
J.-M. Lellouche ◽  
B. Levier ◽  
C. Maraldi ◽  
...  

Abstract. The regional ocean operational system remains a key element in downscaling from large scale (global or basin scale) systems to coastal ones. It enables the transition between systems in which the resolution and the resolved physics are quite different. Indeed, coastal applications need a system to predict local high frequency events (inferior to the day) such as storm surges, while deep sea applications need a system to predict large scale lower frequency ocean features. In the framework of the ECOOP project, a regional system for the Iberia-Biscay-Ireland area has been upgraded from an existing V0 version to a V2. This paper focuses on the improvements from the V1 system, for which the physics are close to a large scale basin system, to the V2 for which the physics are more adapted to shelf and coastal issues. Strong developments such as higher regional physics resolution in the NEMO Ocean General Circulation Model for tides, non linear free surface and adapted vertical mixing schemes among others have been implemented in the V2 version. Thus, regional thermal fronts due to tidal mixing now appear in the latest version solution and are quite well positioned. Moreover, simulation of the stratification in shelf areas is also improved in the V2.


2016 ◽  
Author(s):  
Xueming Zhu ◽  
Hui Wang ◽  
Guimei Liu ◽  
Charly Régnier ◽  
Xiaodi Kuang ◽  
...  

Abstract. In this paper, the performances of two operational ocean forecasting systems, Mercator Océan (MO) in France and South China Sea Operational Forecasting System (SCSOFS) in China, have been examined. Both systems can provide science-based nowcast/forecast products, such as temperature, salinity, water level and ocean circulations. Based on the observed satellite and in-situ data have been obtained in 2012 in the South China Sea, the comparison and validation of the ocean circulations, the structures of the temperature and salinity, and some mesoscale activities are shown. Comparing with the observation, the ocean circulations and SST of MO show better results than those of SCSOFS. However, the structures of temperature and salinity of SCSOFS are better than those of MO. For the mesoscale activities, SST fronts and SST decreasing during the typhoon Tembin of SCSOFS are better agreement with the previous study or satellite data than those of MO; but both of them show some differences from AVISO data. Finally, according to the results compared in above, some suggestions have been proposed for both systems to improve their performances in the near further.


2020 ◽  
Author(s):  
Lungwani Muungo

The purpose of this review is to evaluate progress inmolecular epidemiology over the past 24 years in canceretiology and prevention to draw lessons for futureresearch incorporating the new generation of biomarkers.Molecular epidemiology was introduced inthe study of cancer in the early 1980s, with theexpectation that it would help overcome some majorlimitations of epidemiology and facilitate cancerprevention. The expectation was that biomarkerswould improve exposure assessment, document earlychanges preceding disease, and identify subgroupsin the population with greater susceptibility to cancer,thereby increasing the ability of epidemiologic studiesto identify causes and elucidate mechanisms incarcinogenesis. The first generation of biomarkers hasindeed contributed to our understanding of riskandsusceptibility related largely to genotoxic carcinogens.Consequently, interventions and policy changes havebeen mounted to reduce riskfrom several importantenvironmental carcinogens. Several new and promisingbiomarkers are now becoming available for epidemiologicstudies, thanks to the development of highthroughputtechnologies and theoretical advances inbiology. These include toxicogenomics, alterations ingene methylation and gene expression, proteomics, andmetabonomics, which allow large-scale studies, includingdiscovery-oriented as well as hypothesis-testinginvestigations. However, most of these newer biomarkershave not been adequately validated, and theirrole in the causal paradigm is not clear. There is a needfor their systematic validation using principles andcriteria established over the past several decades inmolecular cancer epidemiology.


2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Jose Antonio Moreira Lima

This paper is concerned with the planning, implementation and some results of the Oceanographic Modeling and Observation Network, named REMO, for Brazilian regional waters. Ocean forecasting has been an important scientific issue over the last decade due to studies related to climate change as well as applications related to short-range oceanic forecasts. The South Atlantic Ocean has a deficit of oceanographic measurements when compared to other ocean basins such as the North Atlantic Ocean and the North Pacific Ocean. It is a challenge to design an ocean forecasting system for a region with poor observational coverage of in-situ data. Fortunately, most ocean forecasting systems heavily rely on the assimilation of surface fields such as sea surface height anomaly (SSHA) or sea surface temperature (SST), acquired by environmental satellites, that can accurately provide information that constrain major surface current systems and their mesoscale activity. An integrated approach is proposed here in which the large scale circulation in the Atlantic Ocean is modeled in a first step, and gradually nested into higher resolution regional models that are able to resolve important processes such as the Brazil Current and associated mesoscale variability, continental shelf waves, local and remote wind forcing, and others. This article presents the overall strategy to develop the models using a network of Brazilian institutions and their related expertise along with international collaboration. This work has some similarity with goals of the international project Global Ocean Data Assimilation Experiment OceanView (GODAE OceanView).


2015 ◽  
Vol 19 (8) ◽  
pp. 3365-3385 ◽  
Author(s):  
V. Thiemig ◽  
B. Bisselink ◽  
F. Pappenberger ◽  
J. Thielen

Abstract. The African Flood Forecasting System (AFFS) is a probabilistic flood forecast system for medium- to large-scale African river basins, with lead times of up to 15 days. The key components are the hydrological model LISFLOOD, the African GIS database, the meteorological ensemble predictions by the ECMWF (European Centre for Medium-Ranged Weather Forecasts) and critical hydrological thresholds. In this paper, the predictive capability is investigated in a hindcast mode, by reproducing hydrological predictions for the year 2003 when important floods were observed. Results were verified by ground measurements of 36 sub-catchments as well as by reports of various flood archives. Results showed that AFFS detected around 70 % of the reported flood events correctly. In particular, the system showed good performance in predicting riverine flood events of long duration (> 1 week) and large affected areas (> 10 000 km2) well in advance, whereas AFFS showed limitations for small-scale and short duration flood events. The case study for the flood event in March 2003 in the Sabi Basin (Zimbabwe) illustrated the good performance of AFFS in forecasting timing and severity of the floods, gave an example of the clear and concise output products, and showed that the system is capable of producing flood warnings even in ungauged river basins. Hence, from a technical perspective, AFFS shows a large potential as an operational pan-African flood forecasting system, although issues related to the practical implication will still need to be investigated.


2008 ◽  
Vol 1 (1) ◽  
pp. 51-57 ◽  
Author(s):  
M Drévillon ◽  
R Bourdallé-Badie ◽  
C Derval ◽  
J M Lellouche ◽  
E Rémy ◽  
...  

2021 ◽  
Vol 4 ◽  
Author(s):  
Felix Fritsch ◽  
Jeff Emmett ◽  
Emaline Friedman ◽  
Rok Kranjc ◽  
Sarah Manski ◽  
...  

The re-emergence of commoning over the last decades is not incidental, but rather indicative of a large-scale transition to a more “generative” organization of society that is oriented toward the planet’s global carrying capacity. Digital commons governance frameworks are of particular importance for a new global paradigm of cooperation, one that can scale the organization of communities around common goals and resources to unprecedented levels of size, complexity and granularity. Distributed Ledger Technologies (DLTs) such as blockchain have lately given new impetus to the emergence of a new generation of authentic “sharing economy,” protected from capture by thorough distribution of power over infrastructure, that spans not only digital but also physical production of common value. The exploration of the frontiers of DLT-based commoning at the heart of this article considers three exemplary cases for this new generation of commons-oriented community frameworks: the Commons Stack, Holochain and the Commons Engine, and the Economic Space Agency. While these projects differ in their scope as well as in their relation to physical common-pool resources (CPRs), they all share the task of redefining markets so as to be more conducive to the production and sustainment of common value(s). After introducing each of them with regards to their specificities and commonalities, we analyze their capacity to foster commons-oriented economies and “money for the commons” that limit speculation, emphasize use-value over exchange-value, favor equity in human relations, and promote responsibility for the preservation of natural habitats. Our findings highlight the strengths of DLTs for a federated scaling of CPR governance frameworks that accommodates rather than obliterates cultural differences and creates webs of fractal belonging among nested communities.


2018 ◽  
Vol 1 ◽  
Author(s):  
Florian Malard ◽  
Philippe Grison ◽  
David Eme ◽  
Cene Fiser ◽  
Jean-François Flot ◽  
...  

Decades of debates around the species problem have resulted in the emergence of a unified species concept with multiple criteria to delimit species taxa. Many biologists now agree to consider species as separately evolving segments of metapopulation lineages (i.e. the species concept), and to consider species taxa (i.e. the elementary units used in biodiversity science) as scientific hypotheses of separately evolving entities. In this framework, sets of species hypotheses are generated using different criteria (i.e. morphological distinguishability, genetic isolation) that mirror the properties expressed by species at different times and sequential orders during the extended and heterogeneous process of speciation. This conceptual and methodological advance in taxonomy has several implications for biodiversity science. First, species taxa represent a heterogeneous set of hypotheses whose properties are contingent on the heterogeneous, continuous and extended nature of speciation. Second, species databases need to integrate information on the diverse properties of species by attributing specimens to multiple species hypotheses generated using different delimitation criteria. Third, biodiversity science at large can provide novel insights into biodiversity processes by incorporating multiple species hypotheses into the analysis of biodiversity patterns. Here, we show how these implications have been taken into account by subterranean biologists. First, we briefly review the criteria and methods used to delimit species in subterranean biology and the diverse sets of species hypotheses they generated. Second, we present a new generation of species occurrence databases that integrate different species criteria and hypotheses while fully respecting the scientific rigor of taxonomy. Last, we show how incorporating multiple species hypotheses into macroecological analyses of European groundwater fauna bolsters our under­standing of the factors shaping large-scale patterns of species richness and geographic range size.


2020 ◽  
Author(s):  
Casimir de Lavergne ◽  
Clément Vic ◽  
Gurvan Madec ◽  
Fabien Roquet ◽  
Amy Waterhouse ◽  
...  

<p>Vertical mixing is often regarded as the Achilles’ heel of ocean models. In particular, few models include a comprehensive and energy-constrained parameterization of mixing by internal ocean tides. Here, we present an energy-conserving mixing scheme which accounts for the local breaking of high-mode internal tides and the distant dissipation of low-mode internal tides. The scheme relies on four static two-dimensional maps of internal tide dissipation, constructed using mode-by-mode Lagrangian tracking of energy beams from sources to sinks. Each map is associated with a distinct dissipative process and a corresponding vertical structure. Applied to an observational climatology of stratification, the scheme produces a global three-dimensional map of dissipation which compares well with available microstructure observations and with upper-ocean finestructure mixing estimates. Implemented in the NEMO global ocean model, the scheme improves the representation of deep water-mass transformation and obviates the need for a constant background diffusivity.</p>


2016 ◽  
Vol 144 (4) ◽  
pp. 1407-1421 ◽  
Author(s):  
Michael L. Waite

Abstract Many high-resolution atmospheric models can reproduce the qualitative shape of the atmospheric kinetic energy spectrum, which has a power-law slope of −3 at large horizontal scales that shallows to approximately −5/3 in the mesoscale. This paper investigates the possible dependence of model energy spectra on the vertical grid resolution. Idealized simulations forced by relaxation to a baroclinically unstable jet are performed for a wide range of vertical grid spacings Δz. Energy spectra are converged for Δz 200 m but are very sensitive to resolution with 500 m ≤ Δz ≤ 2 km. The nature of this sensitivity depends on the vertical mixing scheme. With no vertical mixing or with weak, stability-dependent mixing, the mesoscale spectra are artificially amplified by low resolution: they are shallower and extend to larger scales than in the converged simulations. By contrast, vertical hyperviscosity with fixed grid-scale damping rate has the opposite effect: underresolved spectra are spuriously steepened. High-resolution spectra are converged except for the stability-dependent mixing case, which are damped by excessive mixing due to enhanced shear over a wide range of horizontal scales. It is shown that converged spectra require resolution of all vertical scales associated with the resolved horizontal structures: these include quasigeostrophic scales for large-scale motions with small Rossby number and the buoyancy scale for small-scale motions at large Rossby number. It is speculated that some model energy spectra may be contaminated by low vertical resolution, and it is recommended that vertical-resolution sensitivity tests always be performed.


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