1. Overview of Coupled Model Intercomparison Project (CMIP) and IPCC AR5 Activities Ronald J Stouffer Karl Taylor, Jerry Meehl and many others June 2009

2. Outline Background – Review AR4 – Initialization – Variability Overview of CMIP5/AR5 design – Long term experiments – Near term experiments Questions

3. Land physics and hydrology Ocean circulation Atmospheric circulation and radiation Land physics and hydrology Ocean ecology and Biogeochemistry Atmospheric circulation and radiation Allows Interactive CO 2 Ocean circulation Plant ecology and land use Climate Model (AOGCM) Earth System Model (ESM) Sea Ice An Earth System Model (ESM) closes the carbon cycle

4. About 18 groups using 24 models participated. More than 1000 papers written using CMIP3 database Downloads continue at very high rate CMIP3 /AR4

5. Initialization: How is this done? Implications for you Modelers make a long Pre-industrial control -Typically 1850 or 1860 conditions Perturbation runs start from control - Model related to real years only through radiative forcing - Solar, volcanoes, human emissions, land use, etc. Each ensemble member an equally likely outcome Do not expect wiggles to match – model vs obs

6. Model vs. Observed Global Mean Surface Temperature Anomalies Model Obs-Jones Obs-GISS Year oKoK

7. Global surface temperature oCoC

8. US Surface Temperature oCoC

9. DC Surface Temperature oCoC

10. Natural Variability Natural variability confounds or “hides” the global warming signal. Smaller space scales and shorter time scales exhibit more natural variability Signal to noise ratio much lower for smaller space and time scales Temperature has a relative large signal to noise ratio, precipitation is much smaller S/N ratio

11. Human activities are very likely the cause of the warming of last 100 years. Black line: temperature observation from thermometers. Pink shade: Climate model simulations using all past radiative forcings. Blue shade: Climate model simulation using only natural forcings (solar, volcanoes). IPCC WGI SPM 2007

12. Human activities are likely to be the cause of the warming over last 100 years on each continent. IPCC WGI SPM 2007

13. CMIP5 Background Process started in 2005 Aspen meeting Lots of groups with input – IPCC WG1, 2, 3 authors – Various WCRP and IGBP committees – Lots of individuals Strategy adopted by WGCM in Paris in September 2008

14. Long Term Experiments Core Tier 1 Tier 2 Core: ≥1718 yrs Tier 1: ≥1727 yrs Tier 2: ≥2038 yrs

15. Long Term Experiments Overview AOGCM – control/historical/projections – Physical climate models ESM – control/historical/projections – AOGCM + closed carbon cycle Lots of runs for “understanding”

16. CMIP5 Long Term Experiments AOGCM Core (concentration driven) Control – 500+ years Historical – ~1850 to 2005 Projection – 2006 to 2100 – RCP4.5 (stabilization near 2100) – RCP8.5 (GHG continue to increase) AMIP – Atmosphere-land model, obs SST + sea ice – 1979 to 2008 185020052100

17. Runs for Understanding Core AOGCM or ESM – 1% CO2 increase to 2X (140 years) TCR – 4XCO2 switch-on (150 years) Equilibrium climate sensitivity Atmosphere-land – Hansen style 1XCO2 4XCO2

18. Long Term Experiments AOGCM Tier 1 Historical – More ensemble members – Natural, GHG-only forcing, other? Projection – RCP2.X (GHG continue to decrease) 2006 to 2100 – RCP6.0 (stabilization near 2100) 2006 to 2100 – RCP4.5 2101 to 2300 AMIP – More ensemble members PMIP – see PMIP protocol; AOGCM or ESM – 6KBP – LGM

19. Long Term Experiments AOGCM Tier 2 Historical – Ensemble natural and GHG-only forcings – Ensemble individual forcings Projection – RCP2.X 2101 to 2300 – RCP8.5 2101 to 2300 PMIP – see PMIP protocol; ESM or AOGCM – Last 1000 yrs (850 to 1850)

20. Long Term Experiments ESM Core All AOGCM long term runs plus Control with pCO2 free – 500+ years Historical – emission driven – ~1850 to 2005 Projection – emission driven – RCP8.5 (2006 to 2100)

21. GFDL’s Long Term Experiment Plans CM3 using GHG concentrations and aerosol emissions – Study aerosol-cloud interactions and impact on climate and climate change ESM2M and ESM2G – Study carbon cycle feedbacks in climate change – Study impact of increasing carbon on ecosystems – Study impact of using differing ocean vertical coordinates on simulation and response

22. CMIP5 Near Term Experiments Core Tier 1 Core: 480 yrs Tier 1: ≥1700 yrs Foci Regional information Short lived species Decadal Prediction

23. Near Term - Core 10 year hindcasts – Initialized at 1960, 1965, 1970 … – 3+ ensemble members 30 year forecasts – Initialized at 1960, 1980, 2005 – 3+ ensemble members 196019651970 1985 1980197520001995199020052010 2030

24. Near Term – Tier 1 Increase ensemble size to 10+ Hindcast without volcanoes Runs initialized in 200X – 2001, 2002, 2003, 2004, 2006, 2007, 2008, … Prediction with Pinatubo-like event in 2010

25. Near Term – Tier 1 Investigate role of short live species Investigate alternative initialization methods 100 yr control and 1% run (if not doing long term experiments with same model)

26. Near Term – Tier 1 Time Slice Experiments Time periods – AMIP (1979-2008) and 2026-2035 – Overlap with decadal prediction exps High atmospheric resolution Atmospheric chemistry experiments Study regional impacts Study extreme events

27. GFDL’s Near Term Experiment Plans CM2.1 using Coupled Data Assimilation with ensemble filter techniques – Investigate predictability on decadal time scales High resolution atmosphere-land-only models in time slice mode (25km) – Investigate regional climate change – Study extreme events (hurricanes) Potentially use high resolution coupled models – Study importance of resolution on predictability

28. CMIP5/AR5 Data Serving Distribution data paradigm – Earth System Grid (ESG) software PCMDI still a gateway to data Several new gateways – BMRC, MPI, NCAR, GFDL, … Archive expected to be more than 1 PB CMIP panel oversight – Variable list

29. GFDL Data Serving Node on PCMDI’s network (ESG) of data servers for CMIP5 – Also provides an independent path to GFDL data Currently serving 10’s of TB to external users – Potentially 100’s of CMIP5/AR5 TB available

30. Thank you Questions?

31. Runs for Understanding Tier 1 ESM-only – CO2 increases for bio, CO2 constant for radiation 1% or historical+RCP4.5 AOGCM or ESM – Ensemble 4XCO2 switch-on (5 years) Atmosphere-land – CFMIP simulator – observed SSTs, sea ice See CFMIP protocol – Aqua planet – Hansen Future run with sulfate at year 2000

32. Runs for Understanding Tier 2 ESM-only – CO2 increases for bio, CO2 constant for radiation 1% or historical+RCP4.5 AOGCM or ESM – AC&C chemistry protocol Atmosphere-land – CFMIP simulator – +4C increase SSTs See CFMIP protocol