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Envisat Validation Workshop Atmospheric Chemistry Validation Team Ground-Based Measurements and Campaign Database Subgroup Comparison with MIPAS Pressure, Temperature and Water vapour Profiles. Henk Schets, Royal Meteorological Institute of Belgium, henk.schets@kmi-irm.be. Validation Team.
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Envisat Validation Workshop Atmospheric Chemistry Validation Team Ground-Based Measurements and Campaign Database Subgroup Comparison with MIPAS Pressure, Temperature and Water vapour Profiles Henk Schets, Royal Meteorological Institute of Belgium, henk.schets@kmi-irm.be
Validation Team Projects participating in this presentation : • AOID 222 PI : K. H. Fricke • AOID 9083 PI : V. Cuomo • AOID 300 PI : D. De Muer
Overview • Comparison of MIPAS temperature profiles with radiosounding data from Uccle (RMI Belgium), AOID 300 • Influence of following parameters has been investigated : • distance • temperature • time difference • height (as pressure level) • Comparison of MIPAS p,T and water vapour profiles with data from IMAA-CNS, Italy, AOID 9083 • Comparison of MIPAS temperature and pressure profiles with a statistical modelled atmosphere (University of Bonn), AOID 222
Intercomparison of Temperature Profiles with data from radiosoundings (PTU) launched at Uccle • MIPAS L2 data from 24/10/2002 to 26/11/2002 (43 profiles) • radiosoundings are launched 2/day from Uccle (50.8N, 4.35E) • -> time difference between the measurements is very short • only temperature has been validated • all profiles have been analyzed versus pressure
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) INDIVIDUAL PROFILES Example of a very good agreement between MIPAS and radiosounding : LEFT In black : the sounding temperature profile In blue : the sounding profile rebinned to the same resolution as the MIPAS profile In red : the MIPAS profile RIGHT the relative difference (MIPAS - PTU)/PTU for each MIPAS level
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) INDIVIDUAL PROFILES (2) Probing different airmasses
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU Influence of different parameters • The influence of the time delay, the distance of the scan from Uccle and the temperature on the difference between the sounding and the MIPAS scan has been investigated for different height levels • The statistical significance of this analysis is rather limited because of the small dataset available
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Distance • no discrimination in height level • the largest differences show up from about 500 km distance • indication of an overestimation by MIPAS ?
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Time difference • the largest difference in time is about 3 hours • no indication of a large dependency
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Temperature
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Distribution (1)
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Distribution (2) (preliminary from July to November)
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Height, all profiles
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Height, morning profiles (32)
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Height, evening profiles (11)
Intercomparison of Temperature Profiles with data from Uccle radiosoundings (PTU) Height, profiles closer than 500km (10)
Intercomparison of Pressure andTemperature Profiles with data from IMAA-CNR radiosoundings (PTU)
Intercomparison of Temperature Profiles with a falling sphere model above northern Scandinavia (AOID 222) • preliminary report describing the validation of MIPAS temperature and density profiles • for each MIPAS data point, the model prediction was computed • altitude range from 35 to 93 km • MIPAS data from July and August 2002
Intercomparison of Density and Temperature Profiles with a falling sphere model above northern Scandinavia (AOID 222) Temperature deviation histogram
Intercomparison of Density and Temperature Profiles with a falling sphere model above northern Scandinavia (AOID 222) Density deviation histogram
Intercomparison of Density and Temperature Profiles with a falling sphere model above northern Scandinavia (AOID 222) • Inspection of the profile data indicates a systematic deviation with altitude -> related to the wrong tangent heights in MIPAS data before auxiliary data update (LOS) on 13/11 ? • Comparison with Esrange lidar data is planned
Intercomparison of Water Vapour profiles with Raman Lidar and radiosonde measurements at IMAA-CNR Lidar station 40.60N 15.73E MIPAS 39.76 – 42.65N 29.57-29.80E 18/9/2002 Lidar station 40.60N 15.73E MIPAS 29.13 – 30.03N 12.39-12.80E 28/11/2002
Conclusions and outlook • Agreement between radiosounding and MIPAS temperature profiles is good • Deviation with altitude detected for July and August profiles • Indications of a dependency of the differences between MIPAS and radiosounding temperature profiles on day/night time • More data is needed to assess whether or not these indications are significant • Indication of a deviation of the lowermost MIPAS water vapour measurement from lidar measurement