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

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

Climate Model (AOGCM) Earth System Model (ESM) An Earth System Model (ESM) closes the carbon cycle Atmospheric circulation and radiation Climate Model (AOGCM) Sea Ice Land physics and hydrology Ocean circulation Atmospheric circulation and radiation Allows Interactive CO2 Earth System Model (ESM) Top – Typical AR4 model – physical climate model with atmosphere, ocean, land sea ice components Bottom – Earth System Model – many definitions, for AR5 – closed carbon cycle (green boxes), no implications for fidelity of the atm chemistry. Our ESMs currently have no atmospheric chemistry in this generation model. See our plans for making CM3 an earth system model. Sea Ice Plant ecology and land use Ocean ecology and Biogeochemistry Land physics and hydrology Ocean circulation 3

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

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

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

Global surface temperature oC

US Surface Temperature oC

DC Surface Temperature oC

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

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

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

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

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

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

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 1850 2005 2100

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

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 PMIP – see PMIP protocol; AOGCM or ESM 6KBP LGM

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)

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)

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

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

Near Term - Core 10 year hindcasts 30 year forecasts Initialized at 1960, 1965, 1970 … 3+ ensemble members 30 year forecasts Initialized at 1960, 1980, 2005 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2030

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

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)

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

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 GFDL will use at least 2 different types of models for the near term AR5 experiments. One will be our AR4 model, CM2.1. We have developed an ocean data assimilation system based on that model version. Using output from the data assimilation system, we will initialized the model and run a number of the integrations. We will also develop a very high atmosphere-only model. This model will be used to study extreme events like hurricanes and other regional climate issues. Much of the integration of this model will occur on the machine at Oak Ridge.

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

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

Thank you Questions?

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

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