CFMIP II Plans Mark Webb (Met Office Hadley Centre) Sandrine Bony (IPSL) Rob Colman (BMRC)

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CFMIP II Plans Mark Webb (Met Office Hadley Centre)

Sandrine Bony (IPSL)

Rob Colman (BMRC)

with help from many others…

CFMIP/ENSEMBLES Workshop Paris, April 2007


Modelling and Prediction of Climate variability and change

Outline

Tentative CFMIP II / AR5 timelines

Current plans for various elements of the CFMIP II strategy

How you can contribute…



CFMIP II experiments and CMIP4/AR5 experiments

CFMIP I ran experiments parallel to those in AR4 with enhanced cloud diagnostics (ISCCP simulator)

Our strategy for AR5 is to work to have the best diagnostics in the official AR5 simulations and to minimise the number of experiments that CFMIP II needs to run in parallel

Even if this effort is successful CFMIP II will still run sensitivity experiments with the AR5 model versions in parallel with the official AR5 experiments


Tentative CFMIP II and CMIP4/AR5 timelines

2007 2007 2008 2008 2009 2009 2010 2010 2011H1 H2 H1 H2 H1 H2 H1 H2 H1

CFMIP-2Planning Phase

Defining CMIP4/AR5diagnostic requirements

CFMIPII Pilot studies / Simulator development

Simulators/diagnostics into models

CMIP4/AR5 Experiments/data submission

CFMIP2 Experiments/data submission

Analysis sub-projects


Strategy for a better assessment of cloud feedbacks in AR5

1/ Develop diagnostic techniques for evaluating clouds and modelled cloud climate feedbacks using satellite data

2/ Develop process level diagnostics to better understand physical cloud- climate feedback mechanisms in models

3/ Work with modelling groups to encourage use of detailed cloud diagnostics in the AR5 experiments

4/ Develop a lightweight experimental framework for studying cloud feedbacks

5/ Run co-ordinated sensitivity experiments to understand the impact of different model assumptions on cloud climate feedbacks

6/ Work with the GCSS/parametrization community to assess the credibility of models’ cloud feedback mechanisms










ISCCP cloudcluster evaluation(Williams and Tselioudis, Climate Dynamics 2007)

1/ Diagnostics for cloud evaluation with satellite data


Modelling and Prediction of Climate variability and change Develop use of ‘lightweight’ 2D ISCCP simulator diagnostics for use in clustering studies (Williams, Webb)

- daily mean optical depth (albedo weighted) - cloud top pressure - ISCCP TCC

Alternative to 42 element tau-Pc histograms

This will allow cluster statistics to be collected in long integrations periods without saving/exchanging large volumes of daily data

Pilot study/upgrade ISCCP simulator vn 3.5 by end 2007Modellers upgrade/install by mid 2008?

1a/ ISCCP simulator development



1b/ CFMIP CloudSat/CALIPSO simulator development

Various modules currently under development

Met Office Alejandro Bodas, Mark Webb, Mark RingerIPSL/LMD Marjolaine Chiriaco, Helene Chepfer, Sandrine BonyLLNL Steve Klein, Yuying ZhangCSU John Haynes, Jonny LyoPNL/UW Roger Marchand

Prototype release expected before end 2007Release of official CFMIPII/AR5 version mid 2008Modellers may start installation from early 2008

We plan to add the ISCCP simulator as an additional module










2a/ CFMIP Point diagnostics

- point locations including - GPCI (Teixeira et al) - ARM/BSRN/Cloudnet sites - locations where models show largest spread? - locations with largest observed inter-annual sensitivity?

- 3hrly or timestep sampling of all cloud diagnostics?

- present day and climate change 10-20 years?

- pilot study (Met Office and others?) by end 2007 ? - modellers set up in models by mid 2008






90S 60S 30S EQ 30N 60N 90N90S 60S 30S EQ 30N 60N 90N1.0

0.6

0.2sigma

1.0

0.6

0.2

ΔCloud water (2xco2 - 1xco2, DJF)

-1 0 1

cloud decrease increase

Correlation coefficient (when positive)

contour=3e-6 [kg/kg]

- pilot model inter-comparison (NIES,MetOffice,MPI) end 2007 - modellers set up in models by end 2008

2b/ Cloud condensate tendency analysis (Ogura et al)

Cloud water vs condensation-precip










Time Sampling Frequency

2D ISCCP simulator, fluxes, water paths, clt, stability, w500

3D diagnostics (ISCCP, cl,clw,

omega, u,v)

CloudSat /CALIPSO Simulator

Cloud/T/q tendencies

1) Coupled AOGCM experiments including ESM/Carbon cycle experiments (AR5)Control & 1% coupled Monthly All All(20 and 5 year sub-periods Daily All 5centered at CO2 doubling) 3hr/daily Point 20 20

2) Slab (AR4 or CFMIP II?) Control & 2CO2 slab Monthly All All 5 All(Sub-periods last Daily All 5 5 520 or 5 years of integration) 3hr/daily Point 20 20 5 20

3) AR5 Present day experiments (AMIP, 20C), CFMIP II idealised ( AMIP + patterned SST, Hansen)Monthly All All 5 All

16 yr daily = 85-90 & 98-07 Daily All 16 5 523 year sub-period 85-07 3hr/daily Point 23 23 23 23

4) CFMIP II sensitivity tests: ( AMIP, AMIP + patterned SST, Hansen )AMIP/AMIP+Patterned SST/ Monthly All All 5 All

Proposed diagnostics for AR5/CFMIPII experiments



3/ Working with modellers to include these in AR5/CMIP4

The ISCCP simulator is already in most climate modelsand will be part of standard IPCC diagnostic requirement for AR5 (agreed by WGCM Sep 06)

Cloud tendencies are already diagnosed in many models

Most groups have submitted data to the WGNE-GCSS GPCI

C3S is relatively new, but many groups are interested in making good use of CloudSat/CALIPSO data.

Please start to make the case to the relevant people in your organisation for setting up these diagnostics for CFMIP and AR5!

If AR5 integrations start in late 2008, then this work will need to be done in the next 18 months.










Modelling and Prediction of Climate variability and change Current proposal:

- AMIP like present day (June 1984 – Dec 2007 ) - AMIP + CO2 doubling forcing experiment (Hansen) - AMIP + 1% CMIP2 composite SST pattern (Soden) If significant variations on this are proposed then a pilot study will be necessary

Proposed timetable:

- Pilot study (volunteers?) end 2007 - CFMIP-2 experiments with AR5 versions 2009-2010

4/ Lightweight idealised experimental framework










Modelling and Prediction of Climate variability and change Examples:

- Does suppressing cloud liquid water content feedback increase climate sensitivity? - Does using a stability based cloud fraction reduce climate sensitivity?

Proposed timetable:

- Pilot study (Met Office, MPI, NIES) end 2007 - CFMIP-2 experiments with AR5 versions 2009-2010

5/ Sensitivity tests to assess impact of model assumptions










Modelling and Prediction of Climate variability and change Proposals in this area are very much under discussion as part of the GEWEX/GCSS-CFMIP collaboration arrangements, and are less tied to the CMIP4 timetable.

Having high frequency point/process diagnostics in AR5/CFMIP-2 will help climate modelling and GCSS/process communities to understand cloud feedbacks mechanisms in models and the reasons for their differences.

We need to find ways to bridge the gap between global models and single column/case studies for climate feedback experiments as well as present day.

Doing this should allow us to use CRM/LES/SCM studies to assess our relative confidence in the cloud feedbacks shown by different models.

6/ Assess credibility of cloud feedback mechanisms



Please give us your feedback….

Please take part in our project working groups today – everyone is welcome!

We plan to write a concrete project proposal this summer, based on the recommendations from this meeting.

The aim is to publish this and send out a call for participation from modelling groups at the end of this year.

This will include recommendations for diagnostics to be included in the AR5 experiments, which are expected to be finalised in 2008.


Cloud system composites from Lau & Crane (1995)and Klein and Jakob (1999)

TWP

Documents

CFMIP II Plans Mark Webb (Met Office Hadley Centre) Sandrine Bony (IPSL) Rob Colman (BMRC)