Arctic Systems Modeling Workshop, Montreal July 2009(notes by Elliott)Afternoon Breakout Summaries: Day 1

Holland leads Ice SheetsSea level change the driver -complex in itselfSheet models vary in detail up to fast ice streamsCoastal interactions usually missingSimulated ocean must change volume to invade fjordsResolution must deal with coastal topographyEven finer at grounding line, perhaps dynamic/adaptableUncouple components as pedagogical device to startBetter physics parameterizations required -e.g. calvingAs always observations are limited/limiting

Walsh leads AtmosphereExisting efforts listed as examples -WRF, othersDomain must be flexible, amenable to sensitivity testsData centralization one of the keys -CMIP, PCMDICoherent global to regional interactions -Canadian systemIntegrate emerging modules -e.g. chemistry entering WRFExternals include biogeochemistry, surfaces, albedoImpacts, vulnerability link to customers -Human aspectsAim for extensibility, proceed in steps -chemistry, aerosol, etc.Feedbacks demand a range of time scales up to decades

Flato leads Sea Ice-OceanScience questions abound -too numerous to listThey focus on several challenges to the prevailing wisdomIs an Arctic Systems Model the proper venue?Perhaps a suite of tools and development is the real storyPrioritization will be criticalRegional models can only downsize, must talk to globalNudging discussed as a means to keep regional codes on trackDecentralization of data may be preferable

Cherry leads Terrestrial/PermafrostPermafrost to biogeochemistry links -methane and C in generalLakes need to encompass subgrid scale, thermokarstVegetation should be dynamicVertical resolution improving fast in soil modelsGridded data sets, time series lacking on terrestrial sideHuge gaps in understanding the human dimensionShould ASM be CCSM like, with a single module set?

Steiner leads BiogeochemistryGreat land problems, but participants mainly ocean communityBegan with impacts of trace gases on climate -e.g. DMS, N2OSo obviously, system atmosphere must contain chemistryAll driven by nutrient and organic cycling in upper columnHigher trophic levels play in -up to fish, birds and mammalsEcosystem structure will morph in the futureLinks to albedo abound -DMS and CCN, chlorophyll in iceNew developments -unexpected phases such as ikaite in iceClathrate release of CH4 will be modulated by methanotrophsRegional approach allows fine resolution, boundaries toughCentralization a strong yes but further,Involve modelers in design and implementation of experimentsEmerging module examples -ice algae, sediments, clathrates