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