1. © Crown copyright Met Office Initial assessment of ARIES continuum measurements Stuart Newman Imperial College, 16 December 2008

2. © Crown copyright Met Office B400 flight (18 Sept 2008) Best clear sky conditions encountered – no need for cloud hole hunting ARIES and TAFTS seemed to operate well Reasonably stable atmospheric structure High aerosol loading but IR measurements insensitive to this

3. © Crown copyright Met Office Preliminary data analysis FL340 (250 hPa)FL290 (314 hPa) FL145 (583 hPa) Select only nadir views over ocean to north of Camborne Use dropsonde profile launched from FL340 in line-by-line simulations SST from low level (100 ft) ARIES data

4. © Crown copyright Met Office Longwave IR (self continuum) spread ~ 0.6K

5. © Crown copyright Met Office SST variability Northern data segment used in simulations >1K

6. © Crown copyright Met Office

7. Strong water vapour band

8. © Crown copyright Met Office Continuum MT_CKD too strong?

9. © Crown copyright Met Office NorthSouth ARIES retrieval (B400)

10. © Crown copyright Met Office Summary and future work Preliminary analysis of ARIES nadir data over ocean (zenith data may be subject to calibration biases) B400 case: small brightness temperature biases in (self continuum dominated) longwave window; larger biases in (foreign broadened) strong midwave band Future work: estimate uncertainties in atmospheric profiles and ARIES radiances Include collocated IASI radiances from MetOp overpass in data analysis Corroborate results by comparing with other flight days Intercompare results from ARIES, TAFTS and NPL FTS

11. © Crown copyright Met Office Questions and answers