Susan Bates Ocean Model Working Group Science Liaison

POP2 Numerical and algorithmic developments z* vertical coordinate, eliminate virtual salt fluxes, modify timestepping with conservative Robert filter Anisotropic GM parameterization Langmuir mixing (NOAA WAVEWATCH III is implemented) Gulf Stream and North Atlantic Current path (EaSM) Modeling Ocean Variability and Biogeochemical Cycles (MOBY, EaSM) Increased vertical resolution Land-ocean freshwater exchange parameterization Eddy-resolving ocean model development* Regional ocean modeling studies (ROMS)* Marine ecosystem experiments using ROMS Preliminary MPAS-O experiments

Sea-ice heterogeneity and ocean mixing (CPT) Internal wave driven ocean mixing (CPT) Atlantic Meridional Overturning Circulation variability Data assimilation initialized decadal prediction* National Multi-Model Ensemble (NMME) Project Eddy resolving model forced with CORE IAF data* CESM-CAM5 pre-industrial control (collaboration with CVCWG and PCWG) Comparison of CORE interannually forced POP2 and HYCOM2

CESM configuration CAM5-SE - proposed at ⅛, backup is ¼ POP2-1/10, 60 levels. CICE on POP grid CLM4 on CAM grid. Plan Conduct 10-year present day control on ASD Assess and continue or modify using NSC Enough allocation for 30 years Topics Air-sea interaction associated with ocean fronts Air-sea interaction associated with rapid wind variations Small scale ice processes and impact on climate

Current Status loosely coupled ensemble adjustment Kalman Filter data assimilation, using the DART (Data Assimilation Research Testbed) software, was developed to produce initial states for the decadal prediction activity in support of CESM s participation in CMIP5 Goals Develop a fully coupled system that uses atmosphere and ocean assimilation Produce a calibrated reanalysis dataset from 1950 to 2011 that can be used to create a set of ensemble initial conditions for initializing climate system forecasts

K-Profile Parameterization (KPP) Result of December OMWG meeting Modularize KPP so that it is independent of the dynamical core and can be used across models (MPAS- O, POP, MOM, GOLD, etc.) Modeling Ocean Variability and Biogeochemical Cycles (MOBY, EaSM) The MIT Darwin ecosystem model is working within the CESM framework Currently testing this implementation Production runs to be done on Yellowstone

Purpose: focus on impact of high spatial heterogeneity in sea ice on ocean mixing processes Implemented the Multi-Column Ocean Grid (MCOG) approach in CESM Tested using ocean-ice runs Short (40yr) fully coupled run to assess climate impacts Change code base and run longer coupled simulations Plan longer fully coupled run and integrations with changes in GHGs to look for feedbacks Boundary layer depth difference from control meters

NIWs are missing in CCSM4, partly due to coupling period and partly due to spatial resolution A parameterization has been implemented in the model Leads to improved tropical precipitation and improvement in mid-latitude westerlies Paper submitted to J. Climate Boundary layer depth difference from control meters

Assess effects of bottom topography on the position of the Gulf Stream End goal: develop a parameterization for subgridscale boundary processes Efforts at NCAR currently focused on topographic influence Less smoothing Control SST minus Observations ( C) SST difference with control ( C) More smoothing

Currently preparing new domains for simulation California Current System Benguela Upwelling Option for South- Atlantic domain. New North-East Pacific domain covers most of upwelling bias region. Other options include small domain centered near 17 S to focus on the coastal (nonequatorial) upwelling. Figure. CCSM4 baseline SST biases relative to the Hadley 1 SST dataset years 1982-2008 left) California Current System and right) Benguela upwelling system. The ROMS domain is shown as a dashed line.