1. Do we / why do we want to develop an ASM? Climate working group for WRF –2005 - workshop on model developments for climate studies with WRF (summary of workshop in BAMS) –Develop WRF for high-res climate modeling (cloud resolving scale - 4km) –Evolve WRF towards regional climate system model - couple with ocean model (ROMS), include atmos chemistry –Use WRF for not only downscaling but also upscaling research - two-way coupling between WRF and global model (CCSM) - group at SUNY-Stonybrook Address issue related to improvements in tropical simulations with higher resolution model - tropical channel model based on WRF –Goal to include new developments in standard release of WRF, encourages community development Several efforts are already underway to build regional “physical” climate system model (atmos - ocean - ice - land) –Atmospheric chemistry - several Arctic “impacts” with this Benefit of coordination between these existing efforts, but need to maintain reason for each effort Stretched grid / time slice global models - run AGCM at higher resolution Why do we want to develop an ASM? - see next slide

2. What science questions are best answered with coupled regional models? Downscaling for impacts assessment –Is a system model needed for this? Upscaling of Arctic processes to global climate –Ex. Arctic C fluxes, changes in Arctic terrestrial ecosystems, impact of aerosols on clouds –Small scale processes that have a climatic signifcance –Need to add other examples here Abrupt climate change - rapid decline in sea ice, methane outgassing,… Role of internal Arctic vs external forcing for change in climate Paleoclimate studies –Glacial inception Coastal erosion Regional specific parameterizations Resolve processes in regional model which are sub-grid scale in global models

3. What are the existing modeling and model validation efforts aimed towards answering these questions? WRF Climate working group SMHI, AWI-Potsdam, Jens Christensen European project Coupled ARCMIP recently started DAMOCLES - links to CARCMIP

4. What model and model validation projects are on the horizon aimed towards answering these questions? See previous slide

5. What arctic science questions cannot be answered with limited area regional coupled Arctic models? Stratospheric processes –Importance of stratosphere / troposphere coupling Whole atmosphere processes - above stratosphere, space weather Some processes are still too small scale to be resolved even with a regional model –Hydrology, ecosystem, other? –Could be addressed with multiple nested domains Not all human interactions are / can be included in a system model Meridional transport for one-way regional model –This can be addressed with nested regional model within global model Very long time processes –Changes in deep ocean circ, ice sheet changes, ecosystem changes

6. What science questions are missing from existing efforts?

7. What human systems are relevant to the physical systems being addressed? Are there existing models for these human systems? Land use change / fire / insect outbreaks (C) Hydrology (C) –River runoff temperature –Carbon sources / sinks –Nutrients / sediment Permafrost (C) –Transportation issue / infrastructure –Physical changes - drying of lakes, altered sfc energy budget, Coastal processes Sources of aerosols Industrial development / energy production (O) Transportation (O)

8. What human systems are relevant to the physical systems being addressed? Are there existing models for these human systems? Global politics / Militarization of the Arctic (O) Fisheries (O) Terrestrial ecosystems (C) Oceanic ecosystems (C) Human health (O) –Air quality, transportation of pollutants (airborne and water), disease vectors Extreme events Sea level rise (C) Population growth / demographic change (O)

9. What human systems are relevant to the physical systems being addressed? Are there existing models for these human systems? Which of these human system processes need to be dealt with interactively in an ASM and which can be modeled with offline effort? Coupled processes –Fire - land change - atmos change Offline processes

10. What are reasonable boundaries on the “Arctic system” for your area of research? Storm tracks (or part of) should be included –How far south does this need to extend? –Topographic influence on storms - Greenland, Rockies Size of domain depends on quality of lateral BCs that are available - reanalysis vs GCSMs –Use of upscaling to improve global simulation of atmos circulation Include all land areas that drain into Arctic Ocean Atmospheric differences between high latitudes (>60) and lower latitudes –Pronounced diurnal / seasonal cycle –Atmos. Stability Different size domain for downscaling or upscaling studies Ocean currents –Ocean convection regions