MINUTES OF MIPAS QWG #9, Florence, 1-2 February 2006
University of Florence
Astronomy and Space Science Department
Largo Enrico Fermi, 5
Firenze, Italy

Level2 1/2/2006

2.1 L2 configuration status
2.1.a F. Niro (ESA), makes a prevention on “Level 2 configuration status”. He describes  IPF 4.65 updates. The NRT operations are not going to be restarted yet. IPF 4.65 has been validated, the processing should start on 1st Feb 2006 at DPAC.

J.M. Flaud (LISA) remarks that assimilation people want to know when ESA plans to release data.
T. Fehr (ESA) answers that DPAC has priority on L1 of September/October Reduced Resolution (RR) data then L2, if there are no major problems, the overall reprocessing will take about 1 year.

2.2 Anomaly investigation status
2.2.a F. Niro (ESA) makes a presentation on “Anomaly Investigation Status”

•	“Anomalous processing time”
P. Raspollini (IFAC) recalls that ADFs have been changed to avoid this problem. 
The anomaly is to be considered as closed.
•	“Excessive Chi-square” in NO2 reported in previous meetings. A bug was found and the anomaly is closed.
•	 “Differences on L2 products between v4.61 and v4.62”. There is a discrepancy between IPF and the prototype, the anomaly is now under investigation by DJO, files v4.61 seem better than v4.62.
•	“Beat-check failure on some L2 products”. A discrepancy between IPF and the prototype was found and DJO is investigating.
•	 “NO2 retrieval during polar conditions”. See presentation by P. Raspollini 2.6.b.
•	“Excessive processing time for L2 production of RR data with IPF 4.65”. For instance RR data of 10 Aug 2004 took 15h58'08'' to process and data of 15 Aug 2004 took 9h14'22''.

	T. Fehr notes that the ground segment has problem with processing time longer than 12h. He 	suggests to investigate.
	P. Raspollini asks the number of iterations.
	F. Niro recalls that with RR the number of the scans is doubled (>120 scans).
	B. Carli (IFAC) notices that an increasing factor of 3 or 4 in the computing was expected, as 	a consequence of a larger number of microwindows, a broader spectral range and the double 	of the scans. He also recalls that the 30% duty cycle, makes the total computing time 	comparable to the one used before.

	AI_L2_9.01 ESA to check for the processing specifications at D-PAC

2.3 L2 performance assessment
2.3.a F. Niro makes a presentation on “L2 monitoring”. He gives examples of L2 daily monitoring and L2 monthly monitoring.
	T. Fehr adds that ESA will bring this on-line also for some historic data
	S. Bartha (ASTRIUM) suggests that this report can be useful for L2 that took 16h of 	computing time

Level 2 2/2/2006

2.4 Contents of the L2 baseline upgrade
2.4 S. Ceccherini (IFAC) makes a presentation on “Content of the L2 Baseline Upgrade”, he addresses the modifications described in a document released on 18th Oct 2005.

	T. Fehr asks if the modifications of the cloud filtering are in the document.
	P. Raspollini answers they aren't and suggests to keep the documents separate.
	T. Fehr agrees to keep the documents separate.
	
	AI_L2_9.02 IFAC and UL to produce an update of the Level2 baseline upgrade 	document released on 18th Oct 2005 with separate contributions.

2.5 ML2PP status
S. Bartha explains that there are no updates.

2.6 Level 2 investigation/study status
2.6.a S. Ceccherini makes a presentation on "Update of IFAC AI", he proposes to consider his e-mail on 4/10/2005 and B. Carli on 19/1/2006 as input for SOW
	T. Fehr agrees.

2.6.b P. Raspollini makes a presentation on “NO2 degradation (AI_L2_8.08)”. She explains that instabilities in NO2 profiles seem to be caused by the saturation of NO2 lines below 43km, and suggests that the MW selection should consider the case of enhanced NO2 concentration

	A. Dudhia (OU) agrees. He suggests to add enhanced NO2 profiles to the scenarios used for 	MW selection.
	
	AI_L2_9.03 OU to check if NO2 retrieval can be improved with a different MWs 	selection

2.6.c P. Raspollini makes a presentation on “Investigations on CH4/N2O oscillations”. She investigated the possible causes of oscillations, T errors, convergence, IG are to be excluded. She verified V. Payne's input (T smoothing error) and concluded that this is not the cause for the considered case. A test with different MW selection gives better results on NO2 but only slightly reduces oscillations in CH4.  She concludes that N2O oscillations are caused by systematic error or insufficient information, for CH4 the problem is not solved with the existing MWs. Investigation is ongoing and she will repeat the analysis for further test cases for which correlative measurements are available

	AI_L2_9.04 IMK to provide data sets (T, CH4, N2O) for correlative measurements.
	AI_L2_9.05 IFAC to study this further test cases

2.6.d A. Dudhia makes a presentation on “MW selection for new (1.5km min spacing, floating altitude ±3 km offset) nominal modeh. In Nov 2005 he found a bug and suggests not to trust old MWs for 1.5 km spacing, error-analisys was over-optimistic especially at high altitudes. MWs selection and LUTs are complete for pT, H2O CH4 N2O. There is now a large pT random error that dominates the error budget of other VMR retrievals, while random and systematic errors for other species are acceptable.
	B. Carli asks when the MW will be released
	A. Dudhia answers this can be done in a couple of weeks.
	M. López-Puertas (IAA) says that using pT MWs in a larger band will lead to have problems 	with NLTE
	A. Dudhia answers this is taken into account in the selection
	F. Niro asks if the total error will now be larger
	A. Dudhia answers that this suggests the use of regularisation to reduce the error

2.6.e J. Hurley (OU) makes a presentation on “Analysis of D Band Cloud Flag”. She describes anomalous situations where D Band flags a cloud but the A band does not. She investigates if there is a correlation between these anomalous flagging and extremely low retrieved H2O VMR. She concludes that the correlation is not high enough to use the anomaly as a detection mechanism for poor data.  She investigates on D band sensitivity to clouds and day/night differences in D band, she concludes that D band is not reliable and recommends the use of A band flag instead.

	S. Bartha notes that this result is in contradiction with the algorithm proposed by J. 	Remedios
	T. Fehr adds that comments by J. Remedios are needed.

	AI_L2_9.06, OU and UL: To check the impact of this study on the proposed cloud 	scheme

2.6.f A. Burgess (OU) makes a presentation on RR Retrievals and Oxford L2 Monitoring and shows results on comparison of retrievals made with two L1 files for orbit 17540 (8.2 cm data and 8cm truncated version). He does not find differences in T retrievals
	B. Carli notes that in this case the systematic effect on the average profile of the orbit is also 	important
	A. Burgess confirms that this is a worthwhile test.

A. Burgess shows investigation on retrievals made with two L1 versions of orbit 14404, no differences are found

	B. Dinelli (ISAC) notes that the L1 files have different pointing informations 
	A. Burgess explains the results are plotted against nominal altitudes
	T. Fehr asks to double check the results

	AI_L2_9.07 OU: To check if the correct input files were used in the comparison

A. Burgess continues showing Oxford L2 monitoring web-page

2.6.g H. Sembhi (UL) makes a presentation on “Cloud Detection and Reference Atmospheres”on behalf of J. Remedios and R. Leigh. She presents Band A vs Band D analysis and a new proposed "general" algorithm by J. Remedios. She presents the new IG2 reference climatology database v4.0.

2.6.h T. Steck (IMK) makes a presentation on “Small (or rather negative) O3 values in the tropical tropopause region”. He explains that in IMK O3 retrievals there are a considerable number of negative values of O3 in the tropical tropopause region. This happens also in ESA retrievals, where 10e-10 values appear instead, and he discusses the possible causes.

A discussion is made on the possible causes, negative values are not unrealistic,  they are consistent with statistics if the error bar is large enough. Setting the negative value to a small positive (10e-10) causes a small bias in the average profile but this was required to avoid a possible overflow in the computation of the absorption.

2.6.i M. López-Puertas makes a presentation on “NLTE studies NO2, CH4 N2O”. He describes investigation ongoing for understanding the NLTE processes and quantifying the NLTE effects. He reports first detection of non-LTE in CH4 and N2O emissions.

2.6.j M. Birk (DLR) makes a presentation on “New spectroscopic database of water for MIPAS”. He examines the status (and deficiencies) of current database and goals of the new database. The beta-version of the database will be available on ftp soon. He recommends criteria and precautions to select MWs.

	J.M. Flaud says that check will be needed to avoid inconsistencies since this represents a 	major 	change 
	M. Birk suggests to perform quality assurance checking of the DLR data using the chi2 

2.6.k JM Flaud makes a presentation “NO+ fundamental and first hot ro-vibrational line frequencies”. He shows results of comparison with previous data. He proposes to include the new line positions up to J''=40 in the MIPAS db, for the rest remaining as in HITRAN.

2.6.l B. Carli makes a presentation on "Systematic errors"
 He explains that a reduction of systematic errors is very important. 
	1. Radiometric gain error is presently ±2%. 
	A discussion is made.
	AI_L2_9.08 IMK, DLR:  To provide justification for a reduction in the radiometric 	gain error (within 6 weeks see 2.8.a)

	2. Apodised ILS width tests performed suggest that one order of magnitude reduction is 	possible.
	AI_L2_9.09 ALL: to consider possible causes for correlation of residuals with second 	order error derivative other than ILS broadening (within 6 weeks see 2.8.a).

	3. error on target species profiles is +/- 10%. Is this optimistic?

	A. Dudhia says it is possible to consider the estimate of random error provided by the MW 	selection. He wonders if this is correct or we should use a combination of retrieval and 	climatological errors.

	AI_L2_9.10 Astrium (S. Bartha)  to verify which profile is used of already retrieved 	species (within 6 weeks see 2.8.a).

	4. Profiles of unretrieved gases
	AI_L2_9.11,  UL: To update the error estimate on the climatological values of the 	unretrieved gases (within 6 weeks see 2.8.a).

	5. Spectral db errors
	AI_L2_9.12: LISA to update the error estimates of the spectroscopic database (within 	6 weeks see 2.8.a)

	6. Continuum model
	Used in MWs selection not in the error budget. Maintained

	7. pT error propagation
	This has already been updated.

	8. NLTE effects
	These have already been updated.
 
	9. CO2 line mixing
	AI_L2_9.13: UB to update the CO2 line Mixing model (within 6 weeks see 2.8.a).

	10. Horizontal T gradients
	Confirmed

	AI_L2_9.14: OU to update the list of errors according to input of the AIs from 	AI_L2_9.08 to AI_L2_9.15 (within 8 weeks see 2.8.a).

2.6.m M. López-Puertas “L2 ofl comparison for NO2”. He investigates on a positive bias 5-10% both in day and night. High altitude L2OFL ESA data look unrealistic.

	AI_L2_9.15: OU to process the orbits of 24 September (day/night) for comparison 	with the results of the IMK/IAA retrievals and identify possible differences, in 	particular at high altitudes. 

2.8 L2 workplan
Since some people have an early flight this topic, which involves several interfaces is discussed before the validation activities (2.7).
2.8.a B. Carli describes the “Schedule for ADF2 deliveries”. He reviews actions required for ADF generation. 

Spectroscopic line list (IMK) was never used for  flight data, however this is useful for ORM tests.

Planned ADFs:
	- ADF Reduced Resolution new measurement scenario
	- ADF Full Resolution old measurement scenario
	- ADF: Reduced Resolution old measurement scenario

He shows activity in progress for RR in new scenario
	AI_L2_9.16: OU, within 8 weeks, possibly earlier, OU to deliver MW, OM, LUTs.
	AI_L2_9.17: Astrium, within 8 weeks, possibly earlier, to finalise the format of ILS and 	frequency calculation changes.
	AI_L2_9.18: IMK to update spectroscopic line list within 16 weeks
	AI_L2_9.19: IFAC to define PS2 settings within 16 weeks
	AI_L2_9.20: IFAC to deliver the updated set of ADFs within 18 weeks.

He lists the activities finalised to the update ADFs for FR old measurement scenario in the next 18 weeks. After that a new cycle will be started for the production of the updated ADFs.
New spectroscopic db, and new systematic errors have to be delivered within 8 weeks. This explains the schedule of  the AIs from AI_L2_9.08 to AI_L2_9.15.
	AI_L2_9.21: OU to produce the error spectra within 18 weeks.

General: Next QWG Meeting: We-Fr 14 (afternoon), 15, 16 (morning) June 2006, Location: IFAC, Florence.

2.7 Feedbacks from validation activities
2.7.a Marco Ridolfi describes the “Preliminary results of T validation”. He lists the data used in validation. A generally good agreement is found.

2.7.b Ugo Cortesi describes the “Preliminary results of O3 validation”. He lists the data used in validation. A generally good agreement is found.

2.7.c	 Hermann Oelhaf describes the “Status of validation papers/activity”.
	Minutes of Karlsruhe meeting are available on the FTP-Server
	Draft Paper: 01 April 2006
	Final Paper: 30 April 2006	
	He requests the reprocessing of 4.62 needed for the validation

Splinter Meeting

AI_S_9.01: BOMEM: L1b IODD before 15 February 2006.

AI_S_9.02: BOMEM to provide Level 1b test file for Level 2 before 01 March.

AI_S_9.03: IFAC to provide ASTRIUM with the modified ORM.

AI_S_9.04: ASTRIUM to provide a timeframe of when the work on MIPAS can begin, as well as a deadline for the L2 IODD before 08 February.

The decision was taken to adopt quadratic parametrisation of the frequency shift, first as a monitoring, but already to include implementation capabilities in the next upgrade with a switch in the Level 2.
Level 1 reports Slope (linear fit), Slope (quadratic fit), quadratic (quadratic fit), using spares in the MDS

AI_S_9.04: ESA To clarify if the Level 2 IPF can read “old” Level 1 data

AI_S_9.05: BOMEM to clarify where IFAC can find L1 files (8 and 8.2)