2011 PCWG Workshop Presentations Classification and Complexity of Arctic Sea Ice and Relevance for Modeling Ute Herzfeld, CIRES PCWG Marika Holland, NCAR-CGD Melt Ponds in CICE: An Update Elizabeth Hunke, LANL Arctic Ocean simulation in the CCSM4 Alexandra Jahn The 20th Century Southern Ocean in CCSM4 Nicole Jeffrey Assessing ocean mixing under heterogeneous sea ice coer and subgrid-scale brine rejection parameterization in climate models Meibing Jin Definite, possible, and unlikely mechanisms for enhanced Arctic warming in coupled climate models Jen Kay The importance of internal variability in simulated 21st century sea ice loss Justin Wettstein