Susan Bates Ocean Model Working Group Science Liaison · 2012. 7. 9. · CESM configuration CAM5-SE - proposed at ⅛°, backup is ¼° POP2 - 1/10°, 60 levels. CICE on POP grid

Susan Bates Ocean Model Working Group Science Liaison

Climate Process Teams (CPTs) NSF Earth System Model Projects (EaSM) Anisotropic Gent-McWilliams (GM) parameterization K-Profile Parameterization (KPP) Regional Ocean Modeling System (ROMS)

Climate Simulation Laboratory (CSL) Accelerated Scientific Discovery (ASD) NCAR Strategic Capability (NSC)

POP2 Numerical and algorithmic developments z* vertical coordinate, eliminate virtual salt fluxes, modify time-

stepping 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

Less smoothing More smoothing SST difference with

control (°C)

Control SST minus Observations (°C) 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

Currently preparing new domains for simulation California Current System Benguela 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.

New North-East Pacific domain covers most of upwelling bias region.

Option for South-Atlantic domain. Other options include small domain centered near 17°S to focus on the coastal (non-equatorial) upwelling.

Model Development Updates and Computer Allocations�Project UpdatesCSL Allocation: Development�Oct. 2012 – Jan 2014CSL Allocation: Production�Oct. 2012 – Jan 2014Slide Number 5NSC Data AssimilationProject UpdatesSea-ice heterogeneity CPTNear Inertial Wave (NIW) Mixing CPTSlide Number 10ROMS in CESM