WGNE – Working Group on Numerical Experimentation
Since its first meeting in 1985, the Working Group on Numerical Experimentation (WGNE) has been the leading expert group in the world for the development of atmospheric circulation models used in numerical weather and climate prediction, and related data analysis and assimilation techniques. WGNE reports to its Sponsors: the WCRP Joint Scientific Committee and the WMO Commission for Atmospheric Sciences.
WGNE facilitates best practices in formulating predictive models, for example in terms of parameterizations of sub-grid physical processes, and implementing them numerically. WGNE also reviews objective analysis and data assimilation techniques to improve model initialization and atmospheric re-analyses. This group has been one of most active and efficient promoters of model intercomparison experiments (MIPs), for example, the Atmospheric Model Intercomparison Project (AMIP).
APARC actively cooperates with WGNE to ensure adequate representation of the stratosphere and corresponding processes in atmospheric models and support the development of data assimilation in the stratosphere, including chemical data.
Website for further information:
Working Group on Numerical Experimentation (WGNE)
WGSIP – Working Group on Seasonal-to-Interannual Prediction
The Working Group on Seasonal-to-Interannual Prediction (WGSIP) was established within CLIVAR in 1996 to develop corresponding numerical experimentation, data assimilation, model initialization, forecasting procedures, and measures of forecast skill.
At present WGSIP contributes to WCRP studies on predictability and prediction on a wide range of time scales: from several weeks to seasons, years, and decades. WGSIP is the main coordinator of the WCRP Climate System Historical Forecast Project (CHFP) that aims to find ways of improving skill of prediction due to better representation in models of interactions and processes in the atmosphere, ocean, on land and in the cryosphere.
APARC and WGSIP are closely cooperating on representing stratospheric processes in climate models in order to improve their prediction skill on seasonal time scales and to deepen our understanding of predictability sources. In this context one joint project is the stratospheric extension of CHFP – the Stratosphere-resolving Historical Forecast Project (SHFP).
Websites for further information:
Working Group on Seasonal to Interannual Prediction (WGSIP)
Climate System Historical Forecast Project (CHFP)
WGCM – Working Group on Coupled Modelling
The WCRP Joint Scientific Committee (JSC) established the Working Group on Coupled Modelling (WGCM) in 1997. WGCM fosters the development of coupled climate models, i.e. models representing atmosphere, ocean, and land surface processes, and promotes data assimilation in such models. APARC actively cooperates with WGCM, especially in the area of chemistry-climate models.
WGCM has become the main coordinator of experimental numerical climate predictions and projections. For example, the fifth phase of the Coupled Model Intercomparison Project (CMIP5), a project led by WGCM with contributions from the IGBP project on Global Analysis, Integration, and Modelling (GAIM) and the WCRP Working Group on Seasonal-to-Interannual Prediction (WGSIP), has, for the first time in history, included climate predictions from decades to centuries and beyond. It has provided a boost for further refinement of predictive climate and Earth System models and created the foundation for using numerical predictions of climate in climate services.
Website for further information:
Working Group on Coupled Modelling (WGCM)
GCOS – Global Climate Observing System
The Global Climate Observing System (GCOS) is sponsored by the World Meteorological Organization (WMO), the Intergovernmental Oceanographic Commission (IOC) of UNESCO, the United Nations Environment Programme (UNEP), and the International Council for Science (ICSU). Founded in 1992, it is designed as a long-term, user-driven system to provide comprehensive observations for climate monitoring, climate change detection and attribution, adaptation to climate variability and change, and supporting climate research. GCOS cooperates with sister systems focusing on ocean and terrestrial observations. It is the main mechanism for the review of the adequacy of the observing system in support of the UN Framework Convention on Climate Change (UNFCCC). The GCOS Atmospheric Observations Panel for Climate (AOPC) is responsible for the adequate observation of atmospheric Essential Climate Variables (ECVs). APARC actively cooperates with AOPC to provide expertise and to help formulate the requirements for observations in the stratosphere and upper troposphere, including observations of chemical constituents.
Website for further information:
Global Climate Observing System (GCOS)
GeoMIP – geoengineering Model Intercomparison Project
Geoengineering research was stimulated in the atmospheric science community by Paul Crutzen and Tom Wigley in 2006, when they suggested the idea of temporary geoengineering as an emergency response to climate warming. They suggested that cooling of the Earth’s surface might be achieved by artificial injection of sulphur dioxide into the lower stratosphere, mimicking the effect of volcanic eruptions, which have had a demonstrable cooling effect on climate. Today, various methods exist that are termed “geoengineering”. While carbon dioxide removal is sometimes classified as geoengineering, APARC activities are concerned with solar radiation management, particularly the idea of increasing stratospheric aerosol loading.
Geoengineering cannot be taken lightly as it would involve an unprecedented level of planetary manipulation, and could have very severe consequences. Risks, depending on the method, might include:
- Regional climate change, including a global reduction of precipitation with regional droughts
- Rapid reversal of the cooling effect when the application is stopped
- Continued ocean acidification
- Stratospheric ozone depletion
- Effects on plants by changing the partitioning between direct and diffuse light
- Unknown impacts on cirrus clouds.
Even if the risks are judged to be acceptable, the technical feasibility of any particular method needs to be ensured and the costs need to be properly quantified. There are also unsolved ethical and governance issues. Any societal decision in future will have to be informed by science and APARC activities aim to use models to investigate the impacts of stratospheric geoengineering on the climate and ozone. Several modelling groups within are currently engaged in studies of geoengineering.
Geoengineering is fraught with unknowns that cannot be alleviated without coordinated study. APARC contributes to a geoengineering model inter-comparison project (GeoMIP) that endeavors to fill the need for such a study by prescribing certain experiments which will be performed by all participating climate models. Through this project, we will be able to ascertain commonalities and differences between model results of the climate response to geoengineering.
Website for further information:
Geoengingeering Model Intercomparison Project (GeoMIP)
PCPI – Polar Climate Predictability Initiative
Progress in research on polar climate predictability requires crossing disciplinary boundaries to understand feedbacks between the troposphere, stratosphere, ocean, land, and cryosphere. Processes and modes of variability in the Earth’s climate system that have a polar manifestation may be instrumental for decadal and seasonal-scale climate prediction. Mechanisms that exhibit predictability are often linked to interactions between different components of the Earth System, which are often strong in Polar Regions. Research on polar climate and its predictability requires strong expertise from the APARC community together with pan-WCRP coordination.
Together with the WCRP Climate and Cryosphere (CliC) project, SPARC is leading the WCRP Polar Climate Predictability Initiative (PCPI), whose goal is to improve understanding of the predictability of climate and the effect of human activities on polar climate. PCPI work closely with the World Weather Resear Programme (WWRP) Polar Prediction Project (PPP).
Websites for further information