Page 1 MIPAS Validation Review - ESRIN - 9–13 December 2002 MIPAS Validation Summary - Plenary Session - Herbert Nett ESTEC / EEM-PPP

Page 2 MIPAS Validation Review - ESRIN - 9–13 December 2002 Measured NESR 0

Page 3 MIPAS Validation Review - ESRIN - 9–13 December 2002 Ok In-flight validation (0 – 230) KDynamic range (BB source) 2 * NESR T + 1 % [true source radiance] * NESR T + 5 % [true source radiance] valueWavenumber range [cm -1 ] Radiometric Accuracy  Critical aspects  ice contamination on focal plane optics  non-Linearity of detectors in bands A, AB and B -> strongest impact in band A ! Radiometric Performance

Page 4 MIPAS Validation Review - ESRIN - 9–13 December 2002 Level 2 algorithm verification: critical aspects  variabilities in target gas signatures (latitudinal, day/night dependencies, perturbed chemistry …)  knowledge of systematic error sources (modelling of instrumental errors, interfering species, spectroscopic errors, Non-LTE...)  code robustness wrt instrumental effects & extreme atmospheric conditions

Page 5 MIPAS Validation Review - ESRIN - 9–13 December 2002 Orbital coordinate [deg] Altitude [km] VMR (ppmv) Water vapourOzoneN2ON2O CH 4 HNO 3 NO 2 Results of orbit #504 retrievals: all species

Page 6 MIPAS Validation Review - ESRIN - 9–13 December 2002 Summary: MIPAS Level 2 error budgets Target parameter, species retrieval range [km] estimated error (global average)dominating error (sys only) ESDTotal (random+sys) temperature K2 – 5 KILS, Hitran, O 3 pressure12 – 681 – 3 %3 – 6 %Hitran, GAIN, O 3, O3O3 12 – 604 – 23 %8 – 30 %ILS, Tem, Hitran HNO 3 12 – 423 – 37 %7 – 44 %Hitran, Tem, ILS H2OH2O12 – 604 – 24 %16 – 49 %Hitran, GRA, Tem CH 4 12 – 606 – 20 %11 – 29 %Tem, GRA, Hitran N2ON2O12 – 478 – 26 %13 – 29 %Tem, Hitran, GRA NO 2 24 – 4711 – 27 %13 – 65 %NLTE, Tem, GRA [ Extracted from presentation A. Dudhia / U. of Oxford ] GAIN: gain cal error GRA: horizontal T gradient ILS: ILS shape error Tem: temperature error Hitran: spectrocopy error NLTE: Non-LTE effects

Page 7 MIPAS Validation Review - ESRIN - 9–13 December 2002 MIPAS-B2 vs. MIPAS-Envisat Comparisons Temperature HNO 3 By: H. Oelhaf / FZ-IMK

Page 8 MIPAS Validation Review - ESRIN - 9–13 December 2002 By: J.C. Lambert, V. Soebijanta, BIRA/IABS NDSC /O 3 sonde & MW radiometer Payerne (av., after 13 Nov) NDSC / Lidar OHP Lauder (NZ)

Page 9 MIPAS Validation Review - ESRIN - 9–13 December 2002 Departures MIPAS - EC Improvement after MIPAS ECMWF Global averages, MIPAS temperatures  Good agreement of MIPAS temperatures with ECMWF analyzed temperatures over large part of stratosphere (diff < 2%)  Largest differences at 0.1 hPa (ECMWF model top)  MIPAS too cold at bottom end of profiles especially in tropics (cloud contamination?). Improvement after upgrade on  Very robust. Same features seen every week. By: A. Dethof / ECMWF

Page 10 MIPAS Validation Review - ESRIN - 9–13 December 2002  Reasonable agreement with ECMWF ozone over large part of stratosphere  Some differences might be explained by known ECMWF model bias: e.g. – tropical O3 max. lower in ECMWF than MIPAS ºN: ECMWF > MIPAS over large part of stratosphere  Unrealistically large MIPAS ozone values in lower stratosphere (cloud contamination?). Improvement after upgrade on MIPAS Ozone MIPAS ECMWF Improvement after By: A. Dethof / ECMWF

Page 11 MIPAS Validation Review - ESRIN - 9–13 December 2002 Cloud top height distribution in MIPAS measurements (~4100 profiles, 7 – 25 Sep 2002) By: J. Remedios/ U. Of Leicester

Page 12 MIPAS Validation Review - ESRIN - 9–13 December 2002 Target parameterCategoryResult / Status T, H 2 O, O 3 Sat. I/C & assimilation: ECMWF, UKMet Office, BASCOE/4D, HALOE, ODIN T: good agreement (typ < 2%) O 3 : good, small bias ( ppmv) H 2 O: 5 … 15% bias h > 55 km, < 20 km T, H 2 O, O 3, HNO 3, CH 4, N 2 O, NO 2 Balloons, aircrafts: MIPAS-B2, TRIPLE (in- situ) M-55 (IR/FIR & in- situ) T: good agreement (~ 1K) O 3 : good, small bias(+) H 2 O: too high h > 55 km, too low < 20 km HNO 3 : bias (-) CH 4 : bias (+) for h < 25 km CH 4, N 2 O, NO 2 : tendency to oscillations H 2 O, O 3, HNO 3, CH 4, N 2 O, NO 2 Ground-based: FTIR, LIDAR, MWR good agreement for O 3 other species: analysis ongoing MIPAS L2: Geophysical validation

Page 13 MIPAS Validation Review - ESRIN - 9–13 December 2002 temperature: good agreement with correlative measurements & analyses O 3 : generally good agreement, bias +1…2 ppmv (?) -> spect. database H 2 O: too high > 55 km -> Non-LTE (?) too low cloud contamination, MW choice, conv. thresholds HNO 3 : bias (-) -> updated spectroscopic data (mipas_hitran v2 -> v3) will yield ~ 10 % higher mixing ratios CH 4, N 2 O, NO 2 :tendency to vertical oscillations -> T error propagation (‘F’ - ‘R’ difference in detector NL correction/band A) ACVT-MASI: “the MIPAS data set (including also HNO 3, CH 4, NO 2 ) is the only data set that is self-consistent and can be included in existing assimilation systems” MIPAS L2: Geophysical validation / summary,

Page 14 MIPAS Validation Review - ESRIN - 9–13 December ° Retrieval altitude-range

Page 15 MIPAS Validation Review - ESRIN - 9–13 December 2002  potential for reduced total errors by extended MW selection (pT, H 2 O, …)  perturbations in non-regularised profile retrievals due to oscillations in ‘fw’ – ‘rev’ sweep radiances (re-check after enhanced NL correction scheme in place)  extension of retrieval height range towards higher and lower limb heights will improve the profile accuracy also within the nominal height interval  inaccuracies in spectroscopic line data (incl. error correlations) -> essential also for gephysical validation (HNO 3 …) Lessons learned / critical areas

Page 16 MIPAS Validation Review - ESRIN - 9–13 December 2002 Baseline modifications: L2 algorithm subjectStatus / IPF handle sweeps at low altitudes & low latitudes by constraining base profile correction in pT PDS implementation in progress (-> Feb 2003, tbc) handling of single microwindow OMs recursive pT & H 2 O retrievals cloud detection & filtering of L1B input during L2 pre-processing report cloud index profiles in Level 2 approach: Detailed definition & prototyping -> start early 2003 (tbc) report IG profile information in Level 2 extend retrieval range to < 12 km & 68 km extend microwindow selection for pT & H 2 O other modification (tbd, result of ACVT activities)

Page 17 MIPAS Validation Review - ESRIN - 9–13 December 2002  Re-assess total budgets, take into account: - mean profiles and variabilities of contaminants - impact of assumed profile shape above highest tangent altitude - impact of convergence thresholds Reporting ESD & temperature error propagation -> Level 2 products Systematic components (HITRAN, NLTE, gain,..) -> ’off-line’ information, could be provided as TN & coded data sets (as done for MIPAS Averaging Kernels) MIPAS error budgets

Page 18 MIPAS Validation Review - ESRIN - 9–13 December 2002 Conclusions MIPAS in-flight calibration & characterisation tasks completed (some activities & documentation under finalisation) geophysical validation: first intercomparison results available (ground-based, balloon sensors, assimilation studies, …) instrument in excellent health, consolidated L0 -> L2 processing chain stable algorithm baseline (May ‘02->), only minor changes in aux data important update 13 Nov (LOS pointing correction, L2 tuning parameters) algorithm update in progress (pT/H2O loop, cloud detection)

Page 19 MIPAS Validation Review - ESRIN - 9–13 December 2002 Recommendations Level 1B -> release ok Level 2: -> release after update of IPF (incl. cloud detection, pT-H 2 O iteration loop, mipas_hitran v.3.0) Essential: supply MIPAS data users with - total error budgets - averaging Kernels - spectroscopic database - reports on geophysical validation campaigns

Page 20 MIPAS Validation Review - ESRIN - 9–13 December 2002 The MIPAS Calibration & Algorithm Verification Team P. Mosner/R.GessnerAstrium/D[ instrument engineering / operations ] G. Perron, G. AubertinABB BOMEM [ ESL / Level 1B ] Th. FikselDJO[ L1B&2 s/w engineering ] S. Bartha Astrium/D[ L2 s/w engineering ] B. Carli, P. Raspollini IFAC-CNR[ ESL / Level 2 ] M. Carlotti, M. Ridolfi U. of Bologna[ ESL / Level 2 ] B. Dinelli ISAC-CNR[ ESL / Level 2 ] A.Dudhia, C.D. Rodgers Univ. of Oxford [ ESL / Level 2; project AO # 323 ] J.M. FlaudLPM/Paris [ ESL / Level 2 ] M. Hoepfner/H. Oelhaf FZ-IMK [ ESL / Level 2 ] T.v. ClarmannFZ-IMK[AO#145 & AMIL2DA / L1B&2 analysis ] M. Lopez-PuertasIAA [ project AO # 304 / L2 analysis ] M. Birk/G. WagnerDLR-IMF[ project AO # 652 / L1B analysis ] J.J. Remedios/R. SpangUniv. of Leicester[ project AO # 357 / L1B&2 analysis ] G. SchwarzDLR-IMF [ ESL / Level 2 ] ESTEC: J.C. Debruyn, A. Burgess (now U. Oxford), J. Langen, M. Sanchez, H. Nett ESOC: A. O’Connell (now EUMETSAT), D. Patterson, F. Diekmann, A. Rudolph