MIPAS QWG WEBEX TELECON Meeting 23rd November 2016 Summary + Action Items List

Transcription

1 MIPAS QWG WEBEX TELECON Meeting 23rd November 2016 Summary + Action Items List A summary of the main conclusions of the meeting and the list of the new Action Items are provided in the present document. Angelika Dehn (ESA) underlines that the objectives of the telecon are: o to have updates and show preliminary progress on the validation dataset (the new L1v8); o to have a review/updates of the schedules on L1b and L2, in order to clarify all dependencies and to be ready for the new reprocessing campaigns; o to have an agreement on the next QWG. Level-1 v.8: 1) Feedback on the FAT and Delta-FAT Gaétan Perron (ABB) introduces the first point of his presentation about the FAT and Delta-FAT: the MICAL v8.00 FAT was held at Serco on 24 th /25 th October 2016, and during the testing sections some issues have been found related to: o Compilation from source code; o Comparison with expected results; o Minor Bugs on software. The issues related to compilation, comparison and bugs affecting ADFs generation have been corrected. An updated version has been delivered on 21 st November 2016 on the MIPAS-ftp server, and the Delta-FAT is scheduled for the 24 th November 2016 (and was postponed to 1 st December, via WebEx). 2) Feedback from Level-2 Team Enzo Papandrea (Serco) presents the analysis on radiance performed on the 62 orbits provided by ABB (and detailed spectra for two orbits) and the impacts on GMTR L2 data. o The analysis on the radiance on the 62 orbits through the comparisons [V8_2015 vs V7], [V8 vs V7] and finally [V8 vs V8_2015] show in this last comparison a radiance percentage increment of ~ 1% and a slight negative trend. The [V8 vs V8_2015] comparison diagram shows also a scattered behavior (variation are ~ 4*10-3 %). Enzo Papandrea asks to Gaétan Perron (ABB) if the daily management gain strategy could be the cause of this scatter; Gaétan Perron (ABB) answers that not necessarily the scatter is related to the gain. o Enzo Papandrea (Serco) presents the spectra differences [V8 V8_2015] of single sequences on two orbits (40154 and 30940) with the following three cases and considerations: Orbit 40154, Seq 71: the difference looks like random noise (probably a different offset has been used in the processing). Orbit 40154, Seq 70: the difference looks like if there is a small frequency shift. Orbit 30940, Seq 17: the difference is almost zero. o In the final 3 rd part of the presentation Enzo shows that the T retrieval on ORM PT MWs with GMTR and differences with V7 indicates the good direction and improvements of the new L1 processor.

2 With reference to the second point of the presentation (spectra differences), Gaétan Perron (ABB) says that he needs to investigate if the spectral correction is the same. Anne Kleinert (IMK) asks to verify if the ADFs used for the V8 and V8_2015 are the same. AI_L1_teleconf_01: Gaétan Perron (ABB) to check if spectral corrections, off-set and ADFs used are the same. Piera Raspollini (IFAC) shows the results of tests conducted with ORM v8 introducing the four main points of the presentation: 1. Tests with new Level-1 v8 (the 62 orbits): o Temperature: the L1v8_new L1v8_old differences do not present significant differences (small spread); L1v8_new L1v7 differences show a ~ 0.5 K positive bias in both Full and Reduced resolution. o H 2 O: the L1v8_new L1v8_old differences do not present differences; L1v8_new L1v7 differences show an evident ~ 5% negative bias. o O 3 : the L1v8_new L1v7 differences do not present differences. Piera Raspollini (IFAC) reminds also that L1v8_new and L1v8_old differs for some features (as calibration and pointing). 2. Level 2 ORM v8 problems identified at QWG#42: Temperature Differences V8 vs V7, MA/UA, and tests with HDO: o Regarding the large differences in temperature between V8 and V7 for all measurement modes (especially at high altitudes), the causes seems coming from the use of ECMWF profiles for interfering species profiles (mainly H 2 O); moreover, the application of the horizontal gradients does not resolve these differences. Actually the problem is under investigation. o Since the new observation modes for MA and UA are defined up to 92 km (and not 78 km as in v7), ORM V8 have shown some problems with these MWs and the temperature retrieved at the highest altitude was unrealistically too low. This problem has been solved when retrieved profiles from previous scan (instead of ECMWF profiles) are used in temperature retrieval for interfering species. V8 V7 for MA: Temperature shows a positive bias of ~0.5 K. V8 V7 for UA: Temperature shows a spread [-2 K 2K]. o Preliminary Test with HDO: a test with constant H 2 O profile as a priori vs test without Optimal Estimation (OE) has been done in order to evaluate the measurement origin of the HDO/H 2 O ratio: in the test without OE some problems probably related to aerosols. Investigations are on-going, but the preliminary results with OE seem encouraging. 3. The impacts on level-2 coming from changes in Level-1 and level-2 algorithms and auxiliary data: The major changes have been listed below: o On Level-1 files: Non-linearities correction; Engineering altitudes; Daily gain. o On Level-2 algorithm: Handling of horizontal gradients; Handling of Initial Guess (IG). o On the Auxiliary data:

3 Spectroscopic database / LUTs; MWs for NO 2 OR; MWs for MA and UA; ILS (Note: not included yet). 4. V8_new vs V7_validation data: Piera Raspollini (IFAC) shows pictures on the effects of single and global changes for each species (Full and Optimized resolution in Nominal Mode) according to the following matrix: Impact of modifications in the algorithm ORM V8 L1V7 ORM V8 auxv7 L1V7 ORM V7 auxv7 Impact of new L1 V8 L1V8 ORM V8 auxv8 L1V7 ORM V8 auxv8 Impact of new auxiliary data L1V7 ORM V8 auxv8 L1V7 ORM V8 auxv7 Global differences L1V8 ORM V8 auxv8 L1V7 ORM V7 auxv7 Investigations are ongoing, but the preliminary results highlight: o Effect on temperature: [+0.5 K above 80 Pa] in FR; [+0.5 K between 40-1 hpa] in OR; Good agreement with V7 validation both for FR and OR. o Effect on H 2 O: [-5% below 0.4 hpa; +5% above 0.2 hpa] in FR; [+5% (and larger) below 5 hpa; -5% - -10% above 1 hpa] in OR; In agreement with only V7 in FR. o Effect on O 3 : [±2%] in FR and OR. o Effect on HNO 3 : [< 5% and generally positive] in FR; small and always positive in OR; In agreement with ground measurements. o Effect on CH 4 : [-5% below 100 hpa] in FR; within [± 2%] in OR. o N 2 O 5 changes significantly due to changes in the algorithm. o HCN and HCFC-22 change significantly due to the use of the new auxiliary data. Piera Raspollini (IFAC) summarizes the list of actions/investigations to be completed: o Comparison of MA and UA v8 products with IAA products; o Further tests on V8 new species (interfering species, impact of clouds); o Analysis on some orbits of August-September 2004; o Settings optimization; o Check of H 2 O auxiliary data with J.M Flaud (LISA). B. M. Dinelli (ISAC) observes that the differences on the H 2 O could be related not to the MWs, but to the differences in the computation of the new LUTs. AI_L1_teleconf_02: Piera Raspollini (IFAC) / J.M.Flaud (LISA) to continue the investigations and analysis on H 2 O LUTs and auxiliary data; and to complete the list of actions as per presentation. Level-2 ORM Investigations: Gaétan Perron (ABB) presents the preliminary results on the new ILS parameters. The comparison performed with the previous parameters indicates: o in the OR period, the Chi-2 are similar;

4 o in the FR period, the Chi-2 seems a little bit worse; o the differences in retrievals are mainly within error budget. The analysis of residuals is not yet completed, since a problem on the fitting in full resolution case has been discovered. As observed by J.M.Flaud (LISA), for the ILS parameter the usage of a mixing approach (old version parameters for the FR and new version parameters for the OR) makes no physical sense. AI_L1_teleconf_03: Gaétan Perron (ABB) to complete the analysis on the residuals of the ILS parameters and to provide an assessment within 2 weeks (expected date: 8 th December). Note: A telecon for the ILS parameters is provisionally scheduled for 14/12/2016 (depending if ABB results are available in time 8 th December). Gaétan Perron (ABB) presents the ABB schedule: o generation of ADFs (performed at ABB, through parallel generation process) shall start after the success of delta-fat ; o Dry runs (1 week and 1 month of data) shall start next week; o The complete ADF generation shall be performed within this year; o The ADFs validation shall start in parallel and be concluded in January Piera Raspollini (IFAC) asks Gaétan Perron (ABB) to select and provide the dry-run products and auxiliary data possibly belonging to a time period where CH 4 discontinuities occur (i.e. October 2010). Marco Gai (IFAC) presents the status of L2 v8 processor, confirming that: o All the new features have been developed (including the new output in Netcdf format); o The first internal tests are in progress (including tests on the complete processing chain, on the all observation modes, on the pre-computed ILS, and new L2 output files). The list of activities to be completed before the starting of reprocessing includes: o The complete integration and verification of Log output files; o The error management strategy; o The development of the External tool for pt-error propagation; o The testing and verification of the new Aux Data. Marco Gai (IFAC) explains that the verification and validation strategy for the ORM v8 shall be based on three levels of tests: o Installation Verification test to verify the correct installation of the ORM v.8 package (a verification procedure shall be included in the SUM); o Acceptance Verification test to verify the capabilities of the ORM v. 8 processor to process all different measurement modes of L1b orbits v.8 (a specific technical note shall be provided as annex of the SUM and provided as draft before the first DDS processing); o Verification/Validation test to provide a verification and scientific validation of the Diagnostic Data Set (DDS) L1v7-ORM v.8 and L1v8-ORM v8.0 (an update of the ORM v8 verification plan document will be provided to ESA). He finally confirms that the activities are in line with the schedule (but a part of the reprocessing is depending on the provision of L1v8 dataset). Angelika Dehn (ESA) asks to have an estimation of the ORM v8 performance. Piera Raspollini confirms the availability of the DDS (L1v7 L2v8) at the end of February 2017.

5 Arno Keppens (BIRA) confirms the analysis of the DDS (L1v8 ML2PPv7) within 2 weeks, estimated in April Alessandro Piro (IDEAS+) shows the schedule confirming the main expected milestones: o ADFs v8 delivery: within middle of January 2017; o DDS [L1v7 L2v8]: within the end of February 2017; o QWG#43 shifted in March 2017, date to be defined (provisionally 7 and 8 March). B. M. Dinelli (ISAC) provides a technical presentation on the effects of the ACI (Aerosol Cloud Index) in cloud clearing MIPAS data, compared with the performances obtained with the used Cloud Index (CI). The analysis has been performed on data derived from 12 orbits (one for each month) of 2011, three spectral regions. The conclusions indicate: o The selection of spectra with ACI > 7.0 leads to discard spectra that can be safely analyzed; o The selection of spectra with CI > 4.0 has the same problem above; o FCI > 1.8 definitely identify spectra affected by thick clouds, but retains spectra that are clearly affected by clouds. From the inspection of the Level-2 products obtained with ORM version 8 from the used orbits, a clear correlation does not exist between the final chi-squares and the oscillation quantifier (POQ) with the CI and the ACI values (high chi-squares and POQ have been found irrespective of the CI/ACI values); therefore the continuum fitted by ORM is sufficient to take into account unfiltered clouds/aerosol and: o No new cloud clearing algorithm needed. Angelika Dehn (ESA) concludes the meeting and proposes: o A WebEx meeting on the 14/12/2016 at 14:00, for the conclusive discussion on the ILS. o A WebEx Telecon on 24 th (TBC) January o Next QWG#43: [7 8] or [21-22] March 2017 TBC, in Karlsruhe (IMK), Frascati (ESA-ESRIN) or Milano (ABB).