The main objectives of WP2 are:
- To quantify and reduce uncertainties in climate model projections and to deliver a superior climate model dataset on Arctic marine change (ice cover, air and sea temperature, biological productivity, etc.).
- To improve the understanding of coupled atmosphere, cryosphere, and ocean processes (physical and biological), and climate impacts.
- To quantify freshwater input and flow in the Arctic Ocean.
- To assess pollution effects and climate change impacts on marine Arctic Ecosystems.
- To provide input data (ice cover, temperature (air and ocean), biological production, etc.) to the socio-economic models in the projects (WP4) for selected climate simulations (present to 2100).
- To assess the impacts of the accelerated warming on the productivity and Carbon budget of terrestrial ecosystems in the Arctic and boreal regions.
Uncertainties in current climate models can only be reduced by increasing our understanding of coupled atmospheric, cryospheric and oceanic processes. The observational benchmark dataset from WP1 will be used to evaluate model parametrisations of sea ice (T 2.1). Research will focus on understanding the underlying reasons for discrepancies between models and observations. Analysis of remote sensing based data sets will provide additional information on sea ice properties (T2.2). Data will also be available from a high resolution, eddy-resolving model with assimilated sea ice (T2.3).
Freshwater pathways in the Arctic will be assessed from observations and model results (T2.4). The freshwater distribution is a key player in the coupled ocean-cryosphere-atmosphere processes. This also determines
the nutrient and light conditions for biological production. Uncertainties in model treatments of atmospheric processes, in particular those related to representations of clouds and aerosols will be addressed using an Arctic regional model and used to evaluate the climate model (T2.6). Impacts of mid-latitude pollution and increasing local emissions on aerosols, climate and pollutant deposition to oceans will be assessed. A regional coupled biophysical model system will be used to estimate present day and future biological productivity of the Arctic Seas (T2.7) using atmospheric forcing fields from the improved climate model (T2.5). The skill of the model will be assessed using data from WP1. Data from the climate model and the coupled biophysical model system (T2.5, T2.7) will be analysed and provided for WP4.