1. WP3.1 Radiative closure (EUCAARI)

2. Radiative closure Use in-situ measured (and inferred) aerosol optical properties and radiative transfer code to model fluxes Compare with broad band radiometer measurements on aircraft To date: –Identification of suitable flights (B362 and B374) –Assessment of accuracy of BBRs and need for pitch/roll corrections –Preliminary calculations with Edwards and Slingo (1996)

3. B362 May 6, 2008

4. B362

6. B374 – Radiation flight with CMET May 14, 2008

7. τ(dry)=0.21 τ(dry)=0.24

8. BBR data from B374

9. Aerosol hygroscopicity during B374 Wet nephelometer provides f(RH), ϐ / ϐ 0 Need D/D 0 for full mie scattering code (Tang 1997 growth not appropriate)

10. Further work Still to do…. –Radiative closure with BBRs for aerosol runs (wet aerosol – properties now available from use of wet neph data) –Analysis of orbits/SWS/SHIMS data (to be done by Debbie OSullivan, Met Office) –More radiation flights?