COUPLED MODELING

1. COUPLED MODELING Purpose: Review where the various centers are with their ocean models, how they got there, and outline the major outstanding issues. CMIP5 model and simulation documentations will be much more comprehensive and complete: - standard vocabulary to describe models and simulations, - interactive web-based questionnaire to provide information, - information in a searchable data base linked to the model outputs. Two groups are collaborating: Metafor (E. Guilyardi) and Earth System Curator (V. Balaji, C. DeLuca)

2. CMIP5 Long-term Experiments All simulations are forced by prescribed concentrations except those “E-driven” (i.e., emission-driven). individual forcing ensembles: AMIP & 20 C D & A ensembles extend RCP8.5 & RCP2.X to 2300 RCP2.X, RCP6 natural-only, GHG-only Control, AMIP, & 20 C RCP4.5, RCP8.5 extend RCP4.5 to 2300 lastmillennium Mid-Holocene & LGM E-driven control & 20 C E-driven RCP8.5 aqua planet (clouds) 1%/yr CO2 (140 yrs) abrupt 4XCO2 (150 yrs) fixed SST with 1x & 4xCO2 ensemble of abrupt 4xCO2 5-yr runs patterned ΔSST (clouds) aerosol forcing ca. 2000 radiation code sees 1xCO2 (1% or 20C+RCP4.5) unform ΔSST (clouds) Core: ≥1718 yrs Tier 1: ≥1727 yrs Tier 2: ≥2038 yrs Coupled carbon-cycle climate models only AC&C4 (chemistry) carbon cycle sees 1XCO2 (1% or 20C+RCP4.5) K. Taylor

3. CMIP5 Decadal Prediction Experiments additional predictions Initialized in ‘01, ’02, ’03 … ’09 hindcasts without volcanoes 100-yr “control” & 1% CO2 10-year hindcast & prediction ensembles: initialized 1960, 1965, …, 2005 alternative initialization strategies prediction with 2010 Pinatubo-like eruption 30-year hindcast and prediction ensembles: initialized 1960, 1980 & 2005 increase ensemble sizes from O(3) to O(10) members atmos. chemistry &/or aerosols &/or regional air quality Core: 480 yrs Tier 1: ≥1700 yrs AMIP K. Taylor

4. AMIP ensemble Future “time-slice” ensemble AMIP (1979-2008) future “time-slice” (2026-2035) AMIP SSTs with 4XCO2 aqua planet (clouds) patterned ΔSST (clouds) uniform ΔSST (clouds) CMIP5 Atmosphere-Only Experiments (targeted for computationally demanding and NWP models) Core: 40 yrs Tier 1: ≥185 yrs Tier 2: 30 yrs K. Taylor

5. CMIP5 TIMELINE (WGCM-13) • Now / a few months ago: Centers are ready to start their simulations, • Summer 2010: Data analysis, • December 2010: Model output available to public, • May 2011: Journal articles accepted (submitted??), • Spring 2013: IPCC AR5 published.

6. CMIP5 participating groups (21?) K. Taylor

8. Limited information from GISS, INM, IPSL, and Meteo-France

10. SUMMARY • Model readiness and participation in either coupled carbon cycle experiments or experiment sets vary considerably, • 1850 control integrations, except Hadley Centre (1860), • Mostly level coordinate models with nominal 1o horizontal resolutions, • Redi and GM for tracer mixing are rather uniform, but there are significant differences in diffusivity coefficient choices, e.g., constant, spatially varying, (un)equal thickness and isopycnal, etc., • There appears to be some increase in the use of tidal mixing parameterization, • Vertical mixing scheme as well as horizontal viscosity choices vary.

13. Ocean model biases in preliminary CanCM4 20th century run (no carbon cycle) Differences are between 1980-1999 average and Levitus/PHC climatology SST SSS B. Merryfield

14. Sea Surface Temperature from CCSM4 1850 control 20th Century

16. evaluation & projection hindcasts & forecasts CORE CORE diagnosis “Near-Term” (decadal prediction) “Long-Term” (century & longer) (initialized ocean state) TIER 1 TIER 1 TIER 2 CMIP5: Three Suites of Experiments AMIP CORE “time-slice” TIER 1 TIER 1 TIER 2 TIER 2 Atmosphere-Only (for computationally demanding and NWP models)