Summary on EFI splinter I. Coco Swarm Data Quality Workshop Potsdam 02/12/2014

EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 2 SUMMARY 1.TII: summary of instrument activity and data issues 2.LP: summary of data issues and investigation strategies 3. Validation on-going... 4.Plasma dataset distribution to the users 5.Summary of EFI splinter outcomes and recommendations

TII results and on-going activities (1) Is the “image anomaly” tamed? Crossing fingers, it seems so... EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 3

TII results and on-going activities (2) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 4 Lessons learnt and recommendations: Exposure of instruments to atmosphere is critical, because ionized water vapor impinges on the phosphor screens in a surrounding “quasi-vacuum” environment, and different portions of the detectors can be affected, causing inhomogeneous distributions of the gain. The scrubbing procedure carried on up to now seems to be very effective (and most probably there will no need to repeat it in the future), even though we have not pushed it up to the extent recommended by manufacturers. Gain flattening is not perfect yet (e.g. V sensor on SwC).  Recommendations of the TII community:  The scrubbing cycle is now completed and the three S/C are in ready state. At least the gain map has to be updated on Swarm C, sensor H, so that, for now, such sensor should stay in ready state.  Do start a more “aggressive” procedure (possibly on ScC, sensor V first, TBD), but with a grain of caution: 1) MCP burn-in first at V (Ph V low), then 2) Ramp-up the phosphors, gradually exceeding 5000V, in few steps (e.g. 5200, 5400, ) up to 6000 V.  Considerations/concerns:  The full EFI flight model has never been completely qualified for MCP V 5000 V, even though no harm is envisaged by the manufacturers (MCP single comp. guaranteed up to V, Ph. single comp. guaranteed up to 8000 V).  Phosphor voltage shows overshoots at times during switch-on and ramp-up procedures: from this the suggestion to proceed by steps.

TII results and on-going activities (3) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 5 Characteristics observed on data since the release of the Plasma dataset - Large offsets in along-track flows, typically North component - Corresponding offsets in cross-track flows - Noisy data in low-density regions One expects the average ion velocity at mid latitude to be close to zero (tens m/s), while an “offset” of about 500 m/s is observed.

TII results and on-going activities (4) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 6 Work on-going on data and algos: - Operational CCDBs will be used instead of the instruments ICDBs - Better column-profile two-Gaussian curve-fit estimates - TII a_En,00000 transfer coefficient updated on Swarm A. To be noted: a_En,00000 is not very stable, due to the image anomaly (related to detectors centers accurate determination). This is probably one of the reasons for the offsets observed in the velocity. CEFI-TII verification work put on hold because of the image anomaly

LP results and activity on-going (1) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 7 How to calculate the electron temperature? Low density regions Low gain probe gives poor results High gain probe results are cleaner but often not consistent with the low gain results

LP results and activity on-going (2) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 8 The Sweep mode: highly improved! High gain Low gain - Improvements: better rejection of overflows in linear e- region, low pass filtering of noise, handling of “double- knee” cases. - Median values of sweep-harmonic mode differences: V for P1 (high gain), V for P2 (low gain). P2 mostly used for calculating the S/C potential. - Suggestion/recommendation (M. F ö rster): sweeps are not so bad, and deserve further investigations. Why do not distribute such data as a separate dataset for Cal/Val only?

LP results and activity on-going (3) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 9 How to cope with sweep-induced jumps in T e and V SC ? How much do they really affect the TII processing? Is there really nothing more we can do at instrument level? What is the full “hysteresis” cycle of the S/C charging?  A test procedure has been conceived:  Go through a “severe” sweep cycle for several orbits: e.g. [-5, +5] V and back. This can be done in normal mode, by only properly telecommanding the sweep cycle.  Use the derived V SC values from both probes separately to feed into the TII processing (off-line activity to be set up between IRF and Calgary) A detailed procedure along with TPFs will be provided asap from IRF to FOS. Good TII data are also needed, so that the process would start after the end of this first monitoring loop after the scrubbing.

LP results and activity on-going (4) EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 10 N e now calculated using the ion part of the V-I curve. Not quite the “current”, but rather the “admittance”. As long as the plasma core is O + (few eV energy), the approximation is good and u i ≈ V sc. If the H + distribution becomes important we could get in trouble. To be monitored! N e from LP N e from FP N e (and along-track velocity too!) can be obtained from the Faceplate current:  continuous 16 Hz measurements  powerful diagnostic tool  recommended new “experimental” product for expert users. drawbacks: 1) a sufficiently negative FP potential shall be set (probably not always possible); 2) a number of approximations is involved (not all plasma regimes probably suitable)

Plasma data validation EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 11 Wide catalogues of Swarm-ISR conjunctions have been prepared by both IRF and Univ. of Calgary. Going through the analysis of such conjunctions is time expensive and every help is appreciated! Catalogues could be made available to the users community through the ESA website. Work by Stolle et al. on the climatology comparison with past missions (CHAMP) continues: E.g. Swarm B  Swarm T e seems way too high (250%) wrt past observations  Nevertheless, T e and N e major features are consistent with expectations

A lot of good science can be already done! EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 12

On the plasma datasets EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 13  The EFI quality group recommendation is to open the preliminary dataset to the worldwide users community.  ESA will provide soon the access. Only key point to be fulfilled: information to the users shall be clear, honest and complete about characteristics and limitations of the dataset. Univ. of Calgary, IRF and ESA will review again the release notes, merge them together in a single “user note” document with the relevant information only.  Other independent reviews of the release notes are encouraged but, please, within next week (Friday 12/12 maximum). Send comments to:  Such document can be published as HTML on the ESA website in the first instance and follow as an official ESA or ESL document TBD.  According to the other PDGS already scheduled activities, data will be distributed in January 2015  Other two “experimental” datasets will be soon prepared by IRF and distributed by ESA to the Cal/Val and experts teams: 1) Sweep mode data, 2) Faceplate density (and velocity?) data. Stay tuned!

Recap of main conclusions and recommendations EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 14  TII group recommends a more aggressive scrubbing, even though with some caution.  TII data quality: general science feeling (through comparisons with other dataset in specific case studies) very good! Offsets present probably due to calibration issues still to be resolved.  LP group recommends a “Sweep hysteresis cycle test” for investigating the sweeps side effects on T e and V sc.  LP data quality: general science feeling (through climatology evidence and previous missions comparisons) very good! El. temperature is difficult to assess and seems to be overestimated by a factor 2.5. Sweep results pretty much improved.  LP and TII teams will made available the Swarm-ISR conjunctions catalogues: every help in the validation is more than welcome.  Dataset distribution: previous slide.

Last but not least... EFI status | I. Coco | Potsdam | 05/12/2014 | Swarm Data Quality Workshop | Pag. 15  ESA does not give up and the work on the updates and cross-verification of the PLASMA operational processor progresses:  A new, and much more efficient, prototype concept setup will be finalized in January.  The algorithms changes occurred from June onward will be integrated in the OP by GMV.  Cross-verification scenarios will be prepared in collaboration with IRF, UoC and GMV.  Once cross-verification will be successful, PDGS plasma data will be distributed, replacing the preliminary plasma dataset (late March/ early April 2015?).  The EFI quality group has decided, from January, to have regular “science” teleconferences (bi- weekly?):  Webex based (coordinated by ESA at least at the beginning)  A 20 minutes presentation followed by minutes discussion  Presenters on a voluntary basis  Interested people please contact: