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© Crown copyright Met Office The Cloud Feedback Model Intercomparison Project Plans for CFMIP-2 Mark Webb (Met Office Hadley Centre) Hadley Centre Seminar,

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Presentation on theme: "© Crown copyright Met Office The Cloud Feedback Model Intercomparison Project Plans for CFMIP-2 Mark Webb (Met Office Hadley Centre) Hadley Centre Seminar,"— Presentation transcript:

1 © Crown copyright Met Office The Cloud Feedback Model Intercomparison Project Plans for CFMIP-2 Mark Webb (Met Office Hadley Centre) Hadley Centre Seminar, July 2008

2 © Crown copyright Met Office Acknowledgements Alejandro Bodas-Salcedo, Sandrine Bony, Chris Bretherton, Helene Chepfer, Steve Klein, Adrian Lock, Brian Medeiros, Brian Mapes, Roger Marchand, Tomoo Ogura, Johannes Quaas, Mark Ringer, Pier Siebesma, Brian Soden, Karl Taylor, George Tselioudis, Joao Teixeira, Keith Williams, Minghua Zhang, Yujing Zhang

3 © Crown copyright Met Office Outline CFMIP-1 and CFMIP-2 Evaluation of clouds in climate models Understanding cloud feedback mechanisms in models Assessing their physical credibility Project timescales

4 © Crown copyright Met Office CFMIP-1 ( ) Started by WGCM (WCRP Working Group on Coupled Modelling) Aims were to identify key cloud-climate feedback uncertainties and to link them to observations ISCCP simulator used to evaluate model clouds quantitatively and expose compensating errors Slab and +2K experiments were run in parallel with CMIP3 AOGCMs Results contributed to IPCC 4 th Assessment report (AR4) CFMIP data used in QUMP/UKCIP08 for structural uncertainty estimates Data are available from PCMDI See for details including publications

5 © Crown copyright Met Office Cloud Feedback Model Intercomparison Project Phase 2 (CFMIP-2) Understanding GCM process/sensitivity studies CRMs/LES/SCMs via GCSS A-Train/ISCCP & simulators Assessment of cloud-climate responses [Full proposal available at: ] Coordinators: Mark Webb, Sandrine Bony, George Tselioudis, Chris Bretherton Evaluation

6 © Crown copyright Met Office ISCCP tropical cloud regimes Williams and Webb (in press, Climate Dynamics)

7 © Crown copyright Met Office Cloud regime error metric Williams and Webb (in press, Climate Dynamics)

8 © Crown copyright Met Office CloudSat/CALIPSO cloud profiling radar and lidar on the A-train CloudSat cloud profiling radar (Stephens et al., 2002) CALIPSO/CALIOP cloud profiling lidar (Winker et al, 2007) Vertical profiles of reflectivities from clouds and precipitation

9 © Crown copyright Met Office CFMIP Observational Simulator Package (COSP) ISCCP, CloudSat Radar and CALIPSO Lidar simulators Met Office Alejandro Bodas, Mark Webb, Keith Williams IPSL/LMD Helene Chepfer, Sandrine Bony LLNL Steve Klein, Yuying Zhang CSUJohn Haynes PNL/UWRoger Marchand Test release was made Feb 2008 – in testing with 10 models Plans for MISR, TRMM, RTTOVS and microwave modules

10 © Crown copyright Met Office CloudSat Radar Simulator in MetUM: North Atlantic NWP case study Effective Reflectivity Factor (dBZe) Bodas et al, submitted to JGR

11 © Crown copyright Met Office LIDAR simulator: CALIOP / LMDz-GCM GCM GCM + SIMULATORCALIOP / GOCCP CLOUD FRACTION LOW MID HIGH (H. Chepfer, S. Bony, JL Dufresne, D. Winker, D. Konsta, G. Cesana, G. Sèze)

12 © Crown copyright Met Office Hierarchy of CFMIP-2 experiments to better understand cloud feedback mechanisms in climate models Short SST forced experiments Realistic control SSTs (20 years) Aquaplanet experiments (36 months) Single column model experiments (1-2 months) Additional diagnostics to understand response mechanisms High frequency output at selected locations T,q and cloud tendency diagnostics Sensitivity experiments to understand impact of model assumptions on cloud response mechanisms

13 © Crown copyright Met Office

14 Do aquaplanets predict climate sensitivity? Brian Medeiros, CSU

15 © Crown copyright Met Office Climate sensitivity } Brian Medeiros, CSU Do aquaplanets predict climate sensitivity? Total Feedback λ

16 © Crown copyright Met Office Zhang and Bretherton, J. Climate, 2008 Single column low cloud feedback experiment

17 © Crown copyright Met Office Cloud AmountCloud LiquidMass Flux NCAR CAM3 – negative SW cloud feedback Cloud amount, convective mass flux, cloud liquid all increase GFDL AM2 – positive SW cloud feedback Small cloud amount change, convective mass flux increases and cloud liquid decreases Minghua Zhang, Stony Brook University Solid: control Dashed: +2k control +2k control +2k control +2k

18 © Crown copyright Met Office UCLA LES Negative SW cloud feedback SAM LES: Negative SW cloud feedback Cloud Liquid Mass FluxCloud Amount Cloud Liquid Minghua Zhang, Stony Brook University control +2k control +2k control +2k control +2k control +2k

19 © Crown copyright Met Office Locations for 3 hourly CFMIP-2 output (85) GCSS Pacific and South East Tropical Pacific sections ARM sites/GCSS field studies/locations with feedback spread

20 © Crown copyright Met Office Joao Teixeira, JPL Diurnal cycle in GCM low cloud cover along GCSS-Pacific cross section (GPCI)

21 © Crown copyright Met Office Composite analysis of 3 hourly point output Brian Mapes, University of Miami CRM forced by observationsNCAR CAM3 GFDL AM2 NASA NSIPP2 model

22 © Crown copyright Met Office (Mark Webb, Tomoo Ogura and Adrian Lock) South East Tropical Pacific Section

23 © Crown copyright Met Office (Mark Webb, Tomoo Ogura and Adrian Lock) control +2K SST response Cloud water convective detrainment (mg/kg/s) cloud water (mg/kg) condensation from LW cooling (mg/kg/s)

24 © Crown copyright Met Office (Mark Webb, Tomoo Ogura and Adrian Lock) control +2K SST response Cloud water no convective detrainment (mg/kg) cloud water (mg/kg) no condensation from LW cooling (mg/kg)

25 © Crown copyright Met Office CFMIP-2 timeline 2008 Pilot studies continue WGCM meeting finalises CMIP plans Production releases of simulators Data hosting arrangements in place Modelling groups adopt simulators Joint CFMIP/GCSS meeting on SCM/LES study CMIP and CFMIP-2 experiments run by groups Data submitted to PCMDI Scientific studies submitted for publication 2013 Publication of AR5

26 © Crown copyright Met Office CFMIP-2 plans: summary Evaluation of clouds in climate models continuing use of the ISCCP simulator in CMIP/CFMIP (metrics) development of new radar/lidar simulators for CMIP/CFMIP Understanding cloud feedback mechanisms in models Hierarchy of lightweight climate change experiments High frequency model outputs Analysis of tendency terms Sensitivity tests Assessing physical credibility of cloud feedback mechanisms Idealised cloud feedback studies with CRM/LES/SCMs


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