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© Crown copyright Met Office
Initial assessment of ARIES continuum measurementsStuart Newman
Imperial College, 16 December 2008
© 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
© 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
© Crown copyright Met Office
Longwave IR (self continuum)
spread ~ 0.6K
© Crown copyright Met Office
SST variability
Northern data segment used in simulations
>1K
© Crown copyright Met Office
© Crown copyright Met Office
Strong water vapour band
© Crown copyright Met Office
Continuum MT_CKD too strong?
© Crown copyright Met Office
North South
ARIES retrieval (B400)
© 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
© Crown copyright Met Office
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