Models and modelling tools
EC-Earth3 is a fully-coupled ESM with interacting components describing the atmosphere, ocean, land surface and sea ice with optional components representing atmospheric chemistry, vegetation dynamics, terrestrial and marine carbon cycles as well as interactive ice sheets. At ENVS we run EC-Earth3 in a configuration with active vegetation dynamics and terrestrial and marine carbon cycles. The model can flexibly be configured at different resolutions, and we typically run it with an atmospheric resolution of ~80 km (and 91 levels in the vertical) and 1 degree resolution in the ocean (and 75 levels).
NASA Goddard Institute for Space Sciences fully-coupled ESM modelE has a horizontal resolution of 2◦ x 2.5◦ and 40 vertical layers extending from the surface to 0.1 hPa in the lower mesosphere. modelE can simulate the tropospheric inorganic and organic chemistry, as well as the stratospheric chemistry. The aerosol schemes include black carbon, primary organic carbon, secondary organic carbon, sulfate and nitrate aerosols, mineral dust, and sea-salt. The natural emissions of sea salt, dimethylsulfide (DMS), isoprene, and dust are calculated interactively.
The ORCHIDEE (ORganizing Carbon and Hydrology In Dynamic Ecosystems) land surface model simulates the flow of energy, water, carbon and nitrogen within the soil-plant continuum of terrestrial ecosystems. In addition, fluxes of carbon, nitrogen, water and energy to the atmosphere are simulated. ORCHIDEE models the dominant ecosystem types by sorting them into generic Plant Functional types covering forest biomes, grass- and croplands. ORCHIDEE is a state-of-the-art land surface model utilized within the IPSL Earth system model and contributes to international landmark projects such as the Global Carbon Project.
The three models, EC-Earth3, modelE and ORCHIDEE (IPSL), have all been used in contributions to international intercomparisons and assessments such as CMIP and IPCC.
In addition, we continue to contribute to the development of an ice sheet surface mass balance and firn densification model which has been employed over Greenland, Antarctica and Iceland with inputs from a range of different driving climate models. The model includes snow densification, varying hydraulic conductivity, irreducible water saturation and other effects on snow liquid water percolation and retention and uses this to calculate the surface energy balance, meltwater production, refreezing and runoff through the snow/firn column. Moreover, we use machine learning-based modeling to downscale global- and large-scale climatic changes to regional and local-scale impacts on, for instance, hydrology.
Examples of model applications
We use the EC-Earth to study both large-scale interactions between Arctic climate and mid-latitude changes and the impacts of Arctic feedbacks on local and global scales. For instance, we are using it to investigate how improvements to the representation of Arctic vegetation dynamics impacts the carbon cycle and thereby the local- and large-scale climate changes.
We use the modelE to support various projects and assessment reports including the Arctic Monitoring and Assessment Programme (AMAP) to study the short-lived climate forcers (SLCFs) in the Arctic as well as globally, their transport, and their impacts and interactions with climate in the present day as well as under different future scenarios.
We work on improving the representation of the arctic and boreal ecosystems within ORCHIDEE by including new plant functional types (such as shrubs) into the model, including snow-vegetation feedbacks and by further developing the part of ORCHIDEE simulation dynamic vegetation behavior and competition. The aim of our work is to understand how future climate change will impact the arctic and boreal vegetation and their carbon storage capacities.
