Poor man’s temp attributionCCMVal DT attribution
CCMval radiation comparisonPiers Forster
Cordero and Forster, 2006
30N-30S
1979-2000
AR4 models
Cordero and Forster, 2006
50 hPa
CCMval
• Validation of Chemistry Climate Models – entering 3rd year– Eyring et al. papers
– Myself and Victor Formichev doing CCMVal radiation intercomparison. Victor does stratopause up
– may extend to J values for chemists– May part is now supported by small grant so
should progress faster
Cagnazzo et al ACP, 2007Improvements to ECHAM5 SW scheme
CCMVal Radiation: FutureTesting Radiation schemes
About 8 CCM groups signed up, hopefully get all involvedFollow Collins et al. 2006 procedure• Questionnaire for groups to document radn scheme• Website with zonally averaged Jan climatology ERA40,
up to 0.1 hPa• Series of clear sky GHG perturbations:• Ozone, water vapour, CO2, CH4, N2O• Look at fluxes and heating rates
– Maybe FDH calculations• Maybe extend to: aerosol and cloud
• Worrying about truthing : LBL and Discrete-Ordinate Model (One so far + others)
Problems with strat attribution
IPCC type climate models: poor radiation schemes and resolution
Coupled chemistry models are also now common and don’t prescribe ozone
Don’t trust tropical tropopause response or polar stratospheric dynamical response
Information lost in broad weighting functions
The answer
• Go back to doing Fixed Dynamical Heating rate calculations at high vertical resolution with accurate radiation schemes– Just like I’ve always done!
Randel and Wu ozone - actual absolute monthly values – includes QBO and solar cycle effect on ozone , LLGHGs FDH
Tropics: lower strat
Forster, Solomon, Bodeker, Schofield, and Thompson: draft for GRL
Forster, Solomon, Bodeker, Schofield, and Thompson: draft for GRL
Forster, Solomon, Bodeker, Schofield, and Thompson: draft for GRL
CCMVAL Temperature trendsAustin et al. paper
• Simulations of temperature from models from 1970s until 2000
• Output of zonally averaged, ozone, water vapour, llghgs, temp, (aerosols?)
My task• Do FDH temperature calcs with ozone and
LLGHG trends from model to attribute model trends – i.e. understand model temp response
Top of Atmosphere Fluxes
1985-2005 trends
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