Nucleus for European Modelling of the Ocean

Last updated

The Nucleus for European Modeling of the Ocean (NEMO) is a general model of ocean circulation developed by a European consortium and used in many countries of Europe.

Contents

Composition

NEMO is an ocean modeling platform composed of several models and numerical techniques for the use and processing of incoming and outgoing data. It has five main components:

It can be associated with other components of the climatic system, atmosphere and land surface, by means of OASIS.

Grid

Nemo is available in various configurations. [4]

Global configurations use ORCA tripolar grids, which allow the entire oceanic domain to be covered without singularity points. [5] In fact, the grid formed by the meridians and the parallels has two singularities: the North Pole and the South Pole. Near these two points the mesh size tends to zero, making the use of modeling equations problematic. To overcome the problem, the poles of the ORCA grids are positioned on the terrestrial sphere in such a way as to be located on continents. Since the South Pole is located on the Antarctic continent, a modification of the standard grid is not required, while the North Pole, which is located in the Arctic Ocean, is replaced by two points located one in North America and the other in Siberia. The ORCA grid is available in different horizontal resolutions ranging from about 2 degrees to 1/12 degree.

Development

The development of NEMO is organized and controlled by a European consortium [6] created in 2008 and formed by:

Related Research Articles

<span class="mw-page-title-main">General circulation model</span> Type of climate model

A general circulation model (GCM) is a type of climate model. It employs a mathematical model of the general circulation of a planetary atmosphere or ocean. It uses the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources. These equations are the basis for computer programs used to simulate the Earth's atmosphere or oceans. Atmospheric and oceanic GCMs are key components along with sea ice and land-surface components.

<span class="mw-page-title-main">Sea ice</span> Outcome of seawater as it freezes

Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface. Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions: the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean. Polar packs undergo a significant yearly cycling in surface extent, a natural process upon which depends the Arctic ecology, including the ocean's ecosystems. Due to the action of winds, currents and temperature fluctuations, sea ice is very dynamic, leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs, which are chunks of ice shelves or glaciers that calve into the ocean. Depending on location, sea ice expanses may also incorporate icebergs.

<span class="mw-page-title-main">Pole of inaccessibility</span> Geographic location

A pole of inaccessibility with respect to a geographical criterion of inaccessibility marks a location that is the most challenging to reach according to that criterion. Often it refers to the most distant point from the coastline, implying a maximum degree of continentality or oceanity. In these cases, a pole of inaccessibility can be defined as the center of the largest circle that can be drawn within an area of interest without encountering a coast. Where a coast is imprecisely defined, the pole will be similarly imprecise.

Vicky Pope is a scientist and the former head of the climate predictions programme at the Hadley Centre.

In climatology, the Coupled Model Intercomparison Project (CMIP) is a collaborative framework designed to improve knowledge of climate change. It was organized in 1995 by the Working Group on Coupled Modelling (WGCM) of the World Climate Research Programme (WCRP). It is developed in phases to foster the climate model improvements but also to support national and international assessments of climate change. A related project is the Atmospheric Model Intercomparison Project (AMIP) for global coupled ocean-atmosphere general circulation models (GCMs).

Chooz (French:[ʃo]) was a short baseline neutrino oscillation experiment in Chooz, France. Its major result was setting limits on the neutrino oscillation parameters responsible for changing electron neutrinos into other neutrinos. Specifically, it found that sin2(2θ13) < 0.17 for large δm2 and δm2 > 8×10−4 eV2 for maximal mixing. The results were published in 1999.

Downscaling is any procedure to infer high-resolution information from low-resolution variables. This technique is based on dynamical or statistical approaches commonly used in several disciplines, especially meteorology, climatology and remote sensing. The term downscaling usually refers to an increase in spatial resolution, but it is often also used for temporal resolution. This is not to be confused with image downscaling which is a process of reducing an image from a higher resolution to a lower resolution.

<span class="mw-page-title-main">Geodesic grid</span> Spatial grid based on a geodesic polyhedron

A geodesic grid is a spatial grid based on a geodesic polyhedron or Goldberg polyhedron.

An atmospheric radiative transfer model, code, or simulator calculates radiative transfer of electromagnetic radiation through a planetary atmosphere.

Integrated assessment modelling (IAM) or integrated modelling (IM)  is a term used for a type of scientific modelling that tries to link main features of society and economy with the biosphere and atmosphere into one modelling framework. The goal of integrated assessment modelling is to accommodate informed policy-making, usually in the context of climate change though also in other areas of human and social development. While the detail and extent of integrated disciplines varies strongly per model, all climatic integrated assessment modelling includes economic processes as well as processes producing greenhouse gases. Other integrated assessment models also integrate other aspects of human development such as education, health, infrastructure, and governance.

An atmospheric reanalysis is a meteorological and climate data assimilation project which aims to assimilate historical atmospheric observational data spanning an extended period, using a single consistent assimilation scheme throughout.

DIVA allows the spatial interpolation/gridding of data (analysis) in an optimal way, comparable to optimal interpolation (OI), taking into account uncertainties on observations. In comparison to standard OI, used in Data assimilation, DIVA, when applied to ocean data, takes into account coastlines, sub-basins and advection because of its variational formulation on the real domain. Calculations are highly optimized and rely on a finite element resolution. Tools to generate the finite element mesh are provided as well as tools to optimize the parameters of the analysis. Quality control of data can be performed and error fields can be calculated. Also detrending of data is possible. Finally 3D and 4D extensions are included with emphasis on direct computations of climatologies from ODV spreadsheet files.

<span class="mw-page-title-main">Gerris (software)</span> Computer Software

Gerris is computer software in the field of computational fluid dynamics (CFD). Gerris was released as free and open-source software, subject to the requirements of the GNU General Public License (GPL), version 2 or any later.

<span class="mw-page-title-main">Regional Ocean Modeling System</span> Free-surface, terrain-following, primitive equations ocean model

Regional Ocean Modeling System (ROMS) is a free-surface, terrain-following, primitive equations ocean model widely used by the scientific community for a diverse range of applications. The model is developed and supported by researchers at the Rutgers University, University of California Los Angeles and contributors worldwide.

Ocean general circulation models (OGCMs) are a particular kind of general circulation model to describe physical and thermodynamical processes in oceans. The oceanic general circulation is defined as the horizontal space scale and time scale larger than mesoscale. They depict oceans using a three-dimensional grid that include active thermodynamics and hence are most directly applicable to climate studies. They are the most advanced tools currently available for simulating the response of the global ocean system to increasing greenhouse gas concentrations. A hierarchy of OGCMs have been developed that include varying degrees of spatial coverage, resolution, geographical realism, process detail, etc.

FESOM is a multi-resolution ocean general circulation model that solves the equations of motion describing the ocean and sea ice using finite-element and finite-volume methods on unstructured computational grids. The model is developed and supported by researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), in Bremerhaven, Germany.

CICE is a computer model that simulates the growth, melt and movement of sea ice. It has been integrated into many coupled climate system models as well as global ocean and weather forecasting models and is often used as a tool in Arctic and Southern Ocean research. CICE development began in the mid-1990s by the United States Department of Energy (DOE), and it is currently maintained and developed by a group of institutions in North America and Europe known as the CICE Consortium. Its widespread use in earth system science in part owes to the importance of sea ice in determining Earth's planetary albedo, the strength of the global thermohaline circulation in the world's oceans, and in providing surface boundary conditions for atmospheric circulation models, since sea ice occupies a significant proportion (4-6%) of earth's surface. CICE is a type of cryospheric model.

The Fisheries and Marine Ecosystem Model Intercomparison Project (Fish-MIP) is a marine biology project to compare computer models of the impact of climate change on sea life. Founded in 2013 as part of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP), it was established to answer questions about the future of marine biodiversity, seafood supply, fisheries, and marine ecosystem functioning in the context of various climate change scenarios. It combines diverse marine ecosystem models from both the global and regional scale through a standardized protocol for ensemble modelling in an attempt to correct for any bias in the individual models that make up the ensemble. Fish-MIP's goal is to use this ensemble modelling to project a more robust picture of the future state of fisheries and marine ecosystems under the impacts of climate change, and ultimately to help inform fishing policy.

<span class="mw-page-title-main">Martin curve</span> Mathematical representation of particulate organic carbon export to ocean floor

The Martin curve is a power law used by oceanographers to describe the export to the ocean floor of particulate organic carbon (POC). The curve is controlled with two parameters: the reference depth in the water column, and a remineralisation parameter which is a measure of the rate at which the vertical flux of POC attenuates. It is named after the American oceanographer John Martin.

OceanParcels, “Probably A Really Computationally Efficient Lagrangian Simulator”, is a set of python classes and methods that is used to track particles like water, plankton and plastics. It uses the output of Ocean General Circulation Models (OGCM's). OceanParcels main goal is to process the increasingly large amounts of data that is governed by OGCM's. The flow dynamics are simulated using Lagrangian modelling and the geophysical fluid dynamics are simulated with Eulerian modelling or provided through experimental data. OceanParcels is dependent on two principles, namely the ability to read external data sets from different formats and customizable kernels to define particle dynamics.

References

  1. Rousset, C.; Vancoppenolle, M.; Madec, G.; Fichefet, T.; Flavoni, S.; Barthélemy, A.; Benshila, R.; Chanut, J.; Levy, C. (2015-10-01). "The Louvain-La-Neuve sea ice model LIM3.6: global and regional capabilities". Geosci. Model Dev. 8 (10): 2991–3005. Bibcode:2015GMD.....8.2991R. doi: 10.5194/gmd-8-2991-2015 . ISSN   1991-9603.
  2. Aumont, O.; Ethé, C.; Tagliabue, A.; Bopp, L.; Gehlen, M. (2015-08-13). "PISCES-v2: an ocean biogeochemical model for carbon and ecosystem studies". Geosci. Model Dev. 8 (8): 2465–2513. Bibcode:2015GMD.....8.2465A. doi: 10.5194/gmd-8-2465-2015 . ISSN   1991-9603.
  3. Vidard, A.; Bouttier, P.-A.; Vigilant, F. (2015-04-29). "NEMOTAM: tangent and adjoint models for the ocean modelling platform NEMO". Geosci. Model Dev. 8 (4): 1245–1257. Bibcode:2015GMD.....8.1245V. doi: 10.5194/gmd-8-1245-2015 . ISSN   1991-9603.
  4. Madec, Gurvan (2016). NEMO ocean engine (PDF).
  5. Gurvan Madec; Maurice Imbard (May 1996). "A global ocean mesh to overcome the North Pole singularity". Climate Dynamics . 12 (6): 381–388. Bibcode:1996ClDy...12..381M. doi:10.1007/BF00211684. S2CID   140161719.
  6. "NEMO goernance and strategy".