Modeling the ModelThe Semantics of the CCSM4 Sea Ice Model

Tetherless World ConstellationRensselaer Polytechnic Institute

The Semantic Sea Ice Interoperability Initiative - (Ψ)

• A collaborative project funded by the NSF working to improve semantic interoperability of Arctic data

• Creating sea ice ontologies incorporating scientific knowledge and some elements of traditional knowledge and linked data

• Working to create a community of semantic practitioners in the Arctic

• Seeking to establish Arctic interoperability in regional and global data systems (e.g. GEOSS, WIS, SAON)

• PIs: Mark Parsons, Ruth Duerr, Siri Jodha Singh Khalsa (NSIDC)

Peter Fox, Deborah McGuinness (RPI)

Status• 1st workshop held with

representatives of operational and research communities

• Use cases explored at the workshop: Shipping forecast Albedo parameterization

• Looking at applications of these ontologies: NSIDC SIGRID3 data

available as linked data Auto-conversion between

chart variants• Second workshop planned for

October 2012 Focus on shipping Will include LTK

SW Radiation in Sea Ice

• The Los Alamos Sea Ice Model (CICE) by Hunke et al. used in Community Climate System Model (CCSM4)

• Key features are explicit treatment of SW radiation in ice, snow cover and melt ponds

• Includes subgrid ice thickness distribution and elastic-viscous-plastic dynamics

There can be 5 different categories of ice thickness, plus open water, in each grid cell. Each category can have a mix of 3 possible surface types, shown below.

Ice layer 4Ice layer 4

Ice layer 3Ice layer 3

Ice layer 2Ice layer 2

Ice layer 1Ice layer 1Ice SSLIce SSL

snowsnowSnow SSLSnow SSL

Ice layer 4Ice layer 4

Ice layer 3Ice layer 3

Ice layer 2Ice layer 2

Ice layer 1Ice layer 1Ice SSLIce SSL

Ice layer 4Ice layer 4

Ice layer 3Ice layer 3

Ice layer 2Ice layer 2

Ice layer 1Ice layer 1Ice SSLIce SSL

PondPond

fs fi fp+ + = 1

CICE in CCSM4

Modeling the Model

• Semantically representing CICE will depict: Modeled processes (ice thickness change, ridging

and rafting, melt pond formation, and reflectance, absorption and transmission of SW radiation by the ice pack)

The observations upon which model parameters are based

The observations that can be used to validate the model

• The ontology will serve as a bridge between the operational, research and modeling communities looking at changing sea ice characteristics and polar climate interactions

Concept Map of CICE

Resources/Comments

• SSIII public website at http://nsidc.org/ssiii/• Ontology source files are available at http://code.google.com/p/ssiii/• The SSIII Ontology Browser at http://nsidc.org/ssiii/ontology-view.html• Discussion group at https://nsidc.org/mailman/listinfo/ssiii_dev

12th International Ice Chart Working Group (IICWG) MeetingBritish Antarctic Survey, Cambridge, U.K., October 17-21, 2011

Comments? SiriJodha is reachable at sjsk@nsidc.org or via phone at 303-492-1445