Coupled model intercomparison project

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

Climatology The scientific study of climate, defined as weather conditions averaged over a period of time

Climatology or climate science is the scientific study of climate, scientifically defined as weather conditions averaged over a period of time. This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography, which is one of the Earth sciences. Climatology now includes aspects of oceanography and biogeochemistry.

Climate change Change in the statistical distribution of weather patterns for an extended period

Climate change occurs when changes in Earth's climate system result in new weather patterns that last for at least a few decades, and maybe for millions of years. The climate system comprises five interacting parts, the atmosphere (air), hydrosphere (water), cryosphere, biosphere, and lithosphere. The climate system receives nearly all of its energy from the sun, with a relatively tiny amount from earth's interior. The climate system also gives off energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.

Atmospheric Model Intercomparison Project (AMIP) is a standard experimental protocol for global atmospheric general circulation models (AGCMs). It provides a community-based infrastructure in support of climate model diagnosis, validation, intercomparison, documentation and data access. Virtually the entire international climate modeling community has participated in this project since its inception in 1990.

Contents

CMIP phases

The Program for Climate Model Diagnosis and Intercomparison at Lawrence Livermore National Laboratory has been supporting the several CMIP phases by helping WGCM to determine the scope of the project, by maintaining the project's data base and by participating in data analysis. CMIP has received model output from the pre-industrial climate simulations ("control runs") and 1% per year increasing-CO2 simulations of about 30 coupled GCMs. More recent phases of the project (20C3M, ...) include more realistic scenarios of climate forcing for both historical, paleoclimate and future scenarios.

The Program for Climate Model Diagnosis and Intercomparison (PCMDI) is a program at the Lawrence Livermore National Laboratory in Livermore, California. Livermore is in the San Francisco Bay Area in the United States. It is funded by the Regional and Global Climate Modeling Group (RGCM) and the Atmospheric System Research (ASR) programs of the Climate and Environment Sciences Division of the United States Department of Energy.

Lawrence Livermore National Laboratory federal research institute in Livermore, California, United States

Lawrence Livermore National Laboratory (LLNL) is a federal research facility in Livermore, California, United States, founded by the University of California, Berkeley in 1952. Originally being a branch of the Lawrence Berkeley National Laboratory, the Lawrence Livermore laboratory became autonomous in 1971 and was designated a national laboratory in 1981.

CMIP Phases 1 and 2

According to Lawrence Livermore National Laboratory PCMDI, the response to the CMIP1 announcement was very successful and up to 18 global coupled models participated in the data collection representing most of the international groups with global coupled GCMs. In consequence, at the September 1996 meeting of CLIVAR NEG2 in Victoria, Canada, it was decided that CMIP2 will be an inter-comparison of 1% per year compound CO
2 increase integrations (80 years in length) where CO
2 doubles at around year 70.

Carbon dioxide chemical compound

Carbon dioxide is a colorless gas with a density about 60% higher than that of dry air. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas. The current concentration is about 0.04% (410 ppm) by volume, having risen from pre-industrial levels of 280 ppm. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers and seawater. It is present in deposits of petroleum and natural gas. Carbon dioxide is odorless at normally encountered concentrations. However, at high concentrations, it has a sharp and acidic odor.

CMIP Phase 3

During 2005 and 2006, a collection of climate model outputs was coordinated and stored by PCMDI. [1] The climate model outputs included simulations of past, present and future climate scenarios This activity enabled those climate models, outside the major modeling centers to perform research of relevance to climate scientists preparing the IPCC Fourth Assessment Report (IPCC-AR4). For the CMIP3 a list of 20 different experiments were proposed, [2] and the PCMDI kept the documentation of all the global climate model involved. [3] Additional information and data-sets are in. [4]

Climate Change 2007, the Fourth Assessment Report (AR4) of the United Nations Intergovernmental Panel on Climate Change (IPCC), is the fourth in a series of reports intended to assess scientific, technical and socio-economic information concerning climate change, its potential effects, and options for adaptation and mitigation. The report is the largest and most detailed summary of the climate change situation ever undertaken, produced by thousands of authors, editors, and reviewers from dozens of countries, citing over 6,000 peer-reviewed scientific studies.

CMIP Phase 5

The most recently completed phase of the project (2010-2014) is CMIP5. [5] [6] CMIP5 included more metadata describing model simulations than previous phases. The METAFOR project created an exhaustive schema describing the scientific, technical, and numerical aspects of CMIP runs which was archived along with the output data.

Metadata data about data

Metadata is "data information that provides information about other data". Many distinct types of metadata exist, among these descriptive metadata, structural metadata, administrative metadata, reference metadata and statistical metadata.

The Common Metadata for Climate Modelling Digital Repositories, or METAFOR project, is creating a Common Information Model (CIM) for climate data and the models that produce it.

A conceptual model is a representation of a system, made of the composition of concepts which are used to help people know, understand, or simulate a subject the model represents. It is also a set of concepts. Some models are physical objects; for example, a toy model which may be assembled, and may be made to work like the object it represents.

A main objective of the CMIP5 experiments is to address outstanding scientific questions that arose as part of the IPCC AR4 process, improve understanding of climate, and to provide estimates of future climate change that will be useful to those considering its possible consequences. The IPCC Fifth Assessment Report summarizes information of CMIP5 experiments, while the CMIP5 experimental protocol was endorsed by the 12th Session of the WCRP Working Group on Coupled Modelling (WGCM). [7] Additional information and data-sets are in. [8]

The Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) is the fifth in a series of such reports. The IPCC was established in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP) to assess scientific, technical and socio-economic information concerning climate change, its potential effects and options for adaptation and mitigation.

CMIP Phase 6

Planning meetings for Phase 6 began in 2013, and an overview of the design and organization was published in 2016. By 2018 CMIP6 had endorsed 23 Model Intercomparison Projects (MIPs) involving 33 modeling groups in 16 countries. A small number of common experiments were also planned. The deadline for submission of papers to contribute to the IPCC 6th Assessment Report Working Group I is early 2020. [9]

The structure of the CMIP6 has been extended with respect to CMIP5 by providing an equivalent framework named CMIP Diagnostic, Evaluation and Characterization of Klima (DECK), together with a set of Endorsed MIPs to improve the description of aspects of climate models beyond the core set of common experiments included in DECK. However, CMIP-Endorsed Model Intercomparison Projects (MIPs) are still built on the DECK and CMIP historical simulations, therefore their main goal is just to address a wider range of specific questions. [10] This structure will be kept in future CMIP experiments.

CMIP6 also aims to be consistent regarding common standards and documentation. To achieve that it includes methods to facilitate a wider distribution and characterization of model outputs, and common standard tools for their analyses. A number of guides has been created [11] for data managers, modelers and users.

A set of official/common forcings datasets are available for the studies under DECK, as well as several MIPS. [12] That allows for more sensible comparisons on the model ensemble created under the CMIP6 umbrella.

These common dataset forcings [13] are stored and coordinated by input4MIPS (input datasets for Model Intercomparison Projects). Most of them are freely available here.

Beyond these historical forcings, CMIP6 also has a common set of future scenarios comprising land use and emissions as required for the future Shared Socio-economic Pathway (SSP) and Representative Concentration Pathways (RCPs). [18]

See also

Related Research Articles

General circulation model A type of climate model that uses the Navier–Stokes equations on a rotating sphere with thermodynamic terms for various energy sources

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.

Radiative forcing

Radiative forcing or climate forcing is the difference between insolation (sunlight) absorbed by the Earth and energy radiated back to space. The influences that cause changes to the Earth's climate system altering Earth's radiative equilibrium, forcing temperatures to rise or fall, are called climate forcings. Positive radiative forcing means Earth receives more incoming energy from sunlight than it radiates to space. This net gain of energy will cause warming. Conversely, negative radiative forcing means that Earth loses more energy to space than it receives from the sun, which produces cooling.

The World Climate Research Programme (WCRP) is an international programme that helps to coordinate global climate research. The WCRP was established in 1980, under the joint sponsorship of the World Meteorological Organization (WMO) and the International Council for Science (ICSU), and has also been sponsored by the Intergovernmental Oceanographic Commission (IOC) of UNESCO since 1993.

Climateprediction.net (CPDN) is a distributed computing project to investigate and reduce uncertainties in climate modelling. It aims to do this by running hundreds of thousands of different models using the donated idle time of ordinary personal computers, thereby leading to a better understanding of how models are affected by small changes in the many parameters known to influence the global climate.

HadCM3 is a coupled atmosphere-ocean general circulation model (AOGCM) developed at the Hadley Centre in the United Kingdom. It was one of the major models used in the IPCC Third Assessment Report in 2001.

C4MIP (more fully, Coupled Climate Carbon Cycle Model Intercomparison Project) is a joint project between the International Geosphere-Biosphere Programme (IGBP)and the World Climate Research Programme (WCRP). It is a model intercomparison project along the lines of the Atmospheric Model Intercomparison Project, but for global climate models that include an interactive carbon cycle.

A climate ensemble involves slightly different models of the climate system. There are at least five different types, to be described below. For the equivalent in numerical weather prediction, see ensemble forecasting.

A transient climate simulation is a mode of running a global climate model (GCM) in which a period of time is simulated with continuously-varying concentrations of greenhouse gases so that the climate of the model represents a realistic mode of possible change in the real world.

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.

Geophysical Fluid Dynamics Laboratory Coupled Model is a coupled atmosphere–ocean general circulation model (AOGCM) developed at the NOAA Geophysical Fluid Dynamics Laboratory in the United States. It is one of the leading climate models used in the Fourth Assessment Report of the IPCC, along with models developed at the Max Planck Institute for Climate Research, the Hadley Centre and the National Center for Atmospheric Research.

Global Energy and Water Exchanges international research project

The Global Energy and Water Exchanges project is an international research project and a core project of the World Climate Research Programme (WCRP).

TOMCAT/SLIMCAT is an off-line chemical transport model (CTM), which models the time-dependent distribution of chemical species in the troposphere and stratosphere. It can be used to study topics such as ozone depletion and tropospheric pollution, and was one of the models used the IPCC report on Aviation and the Global Atmosphere. It incorporates a choice of detailed chemistry schemes for the troposphere or stratosphere, and an optional chemical data assimilation scheme.

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.

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.

Brian C. O'Neill is an American earth system scientist who studies the relationship between future societal development, emissions, and climate change impacts. O'Neill is known for interdisciplinary work on climate and human systems, in particular population and climate change. He was also involved in the development of the shared socioeconomic pathways (SSPs) to be used in scenario analysis. He served as a lead author for several Intergovernmental Panel on Climate Change reports.

Earth systems Models of Intermediate Complexity (EMICs) form an important class of climate models, primarily used to investigate the earth's systems on long timescales or at reduced computational cost. This is mostly achieved through operation at lower temporal and spatial resolution than more comprehensive general circulation models (GCMs). Due to the non-linear relationship between spatial resolution and model run-speed, modest reductions in resolution can lead to large improvements in model run-speed. This has historically allowed the inclusion of previously unincorporated earth-systems such as ice sheets and carbon cycle feedbacks. These benefits are conventionally understood to come at the cost of some model accuracy. However, the degree to which higher resolution models improve accuracy rather than simply precision is contested..

References

  1. ↑ "CMIP3-Info". pcmdi.llnl.gov. Retrieved 2018-05-20.
  2. ↑ "CMIP3-Experiments". pcmdi.llnl.gov. Retrieved 2018-05-20.
  3. ↑ "CMIP3-Models". pcmdi.llnl.gov. Retrieved 2018-05-20.
  4. ↑ "CMIP3-Overview". cmip.llnl.gov. Retrieved 2018-05-20.
  5. ↑ "ESGF-LLNL - Home | ESGF-CoG". esgf-node.llnl.gov. Retrieved 2017-10-09.
  6. ↑ "There is still no room for complacency in matters climatic". The Economist. Retrieved 2017-10-09.
  7. ↑ Taylor, K. E.; Stouffer, R. J.; Meehl, G. A. (2012-03-01). "An Overview of CMIP5 and the Experiment Design". BAMS. 93 (4): 485–498. doi:10.1175/BAMS-D-11-00094.1.
  8. ↑ "CMIP5-Overview". cmip.llnl.gov. Retrieved 2018-05-20.
  9. ↑ Eyring, Veronika; et al. "Overview of the Coupled Model Intercomparison Project Phase 6 (CMIP6) Experimental Design and Organization" (PDF). Retrieved 6 July 2018.Cite web requires |website= (help)
  10. ↑
  11. ↑
  12. ↑ "CMIP6_Forcing_Datasets_Summary". Google Docs. Retrieved 2018-07-18.
  13. ↑
  14. ↑ Meinshausen, M.; Vogel, E.; Nauels, A.; Lorbacher, K.; Meinshausen, N.; Etheridge, D. M.; Fraser, P. J.; Montzka, S. A.; Rayner, P. J. (2017-05-31). "Historical greenhouse gas concentrations for climate modelling (CMIP6)" (PDF). Geosci. Model Dev. 10 (5): 2057–2116. doi:10.5194/gmd-10-2057-2017. ISSN   1991-9603.
  15. ↑ Checa-Garcia, Ramiro; Hegglin, Michaela I.; Kinnison, Douglas; Plummer, David A.; Shine, Keith P. (2018-04-06). "Historical Tropospheric and Stratospheric Ozone Radiative Forcing Using the CMIP6 Database". Geophysical Research Letters. 45 (7): 3264–3273. doi:10.1002/2017gl076770. ISSN   0094-8276.
  16. ↑ Stevens, B.; Fiedler, S.; Kinne, S.; Peters, K.; Rast, S.; Müsse, J.; Smith, S. J.; Mauritsen, T. (2017-02-01). "MACv2-SP: a parameterization of anthropogenic aerosol optical properties and an associated Twomey effect for use in CMIP6". Geosci. Model Dev. 10 (1): 433–452. doi:10.5194/gmd-10-433-2017. ISSN   1991-9603.
  17. ↑ Matthes, K.; Funke, B.; Andersson, M. E.; Barnard, L.; Beer, J.; Charbonneau, P.; Clilverd, M. A.; Dudok de Wit, T.; Haberreiter, M. (2017-06-22). "Solar forcing for CMIP6 (v3.2)". Geosci. Model Dev. 10 (6): 2247–2302. doi:10.5194/gmd-10-2247-2017. ISSN   1991-9603.
  18. ↑ O'Neill, B. C.; Tebaldi, C.; van Vuuren, D. P.; Eyring, V.; Friedlingstein, P.; Hurtt, G.; Knutti, R.; Kriegler, E.; Lamarque, J.-F. (2016-09-28). "The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6". Geosci. Model Dev. 9 (9): 3461–3482. doi:10.5194/gmd-9-3461-2016. ISSN   1991-9603.
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