Report from GRWG 2019

1. Report from GRWG 2019 20th GSICS Executive Panel, Sochi, Russian Federation, 16-17 May 2019 Xiuqing (Scott) Hu, DohyeongKim, Fangfang Yu GRWG Chair

2. Overview • Membership and Chairing • GRWG Activities Summary 2018/2019 • 4 Subgroups progress • Actions and Recommendations • GRWG Work Plan 2019/2020

3. New GRWG Chairing and new members Current nomination to GRWG (36 members): 5 CMA, 2 CNES, 4 EUMETSAT, 1 IMD, 1 ISRO, 3 JAXA, 3 JMA, 3 KMA, 4 NASA, 6 NOAA, 1 ROSHYDROMET, 2 USGS and 1 WMO, No NIST? New members: ESA, SITP EP-19 decided to invite the European Space Agency to become a full member of the GSICS Executive Panel. GSICS also considers inviting the Shanghai Institute of Technical Physics, Chinese Academy of Sciences (SITP/CAS) to join GSICS.

4. GRWG Chairing • New current GRWG Chair and vice chairs were approved by GSICS-EP-19(June 2018) , Now it is the first year of their 3 years of leading and chairing (GSICS ToR ref: GSICS-RD004-v2.0) • The GRWG chair is assisted by two vice-chairs, one being the former chair, and the other being the expected future chair. • The GRWG chair is designated for three years (renewable) with a primary role as defined in its ToR. • GRWG Chairing : three years • Chair : Scott Hu(CMA), 2018. 6 (approved by EP-19) ~ 2021 • Vice-Chair : Dohyeong Kim (KMA), Fangfang Yu (NOAA) • Special thanks to GDWG chair Masaya and all sub-group chairs • GDWG chair’s great job for GSICS annual meeting 2019 agenda arrangement and so much coordination with all the members. • Sub-group chairs for the agenda arrangement and discussion, webmeeting topics design.

5. Overview • Membership and Chairing • GRWG Activities Summary 2018/2019 • Actions and web meeting • Summary of activities • GRWG Work Plan 2019/2020

6. 2019 GRWG/GDWG Annual Meeting, Frascati, Italy • Monday: Mini Conference + Agency Reports(Plenary) • Tuesday: Plenary: Sub-Group Briefing Report, Special session on re-calibration/re-processing • Wednesday: GRWG : VIS/NIR Sub-Group+ MW Sub-Group, GDWG • Thursday: GRWG : IR Sub-Group , UV Sub-Group, GDWG • Friday: Briefing+Wrap-up(Plenary)

7. 2019 Annual meeting summary • 15 Sessions and 10 Items were discussed • 2018/2019 Actions • 70 Actions generated • GRWG: 15 actions; 5 GWG actions; 1 decision; 3 recommendation • IR subgroup : 13 actions 2 decisions; 1 recommendation • VISNIR subgroup : 1 recommendations • MW subgroup : 10 actions; 1 decision; 2 recommendations • UV subgroup : 3actions; 1 recommendation • GCC: 1 action • GDWG: 28 actions; 3 recommendations

8. Actions on GRWGfrom 2019 annual meeting A.GRWG.2019.2e.1: CNES to report on progress with Lunar thermal infrared model study by 2020 meeting. A.GRWG.2019.3b.1: Scott Hu (CMA) to ensure that POC for SWTT from each agency be nominated. A.GRWG.2019.3m.1:SirishUprety (NOAA) to report back on outcome of comparison of VIIRS v2 versus NASA SIPS dataset. A.GRWG.2019.3n.1: Bill Bell (ECMWF) to clarify time scale with the partner agencies for input data needed for ERA-6 activities. A.GRWG.2019.3p.1: Fangfang Yu (NOAA) to set-up a web meeting to initiate a discussion on establishing a strawman algorithm for GEO-GEO inter-comparisons. A.GWG.2019.3t.1: Toshiyuki Kurino (WMO) to provide account access to update WMO GSICS website to GCC, GDWG and GRWG. A.GRWG.2019.4i.1: Tom Stone (USGS) to present a request to LASP to provide a reference solar irradiance spectrum based on the TSIS project (a static and high resolution solar spectrum scaled to TSIS). A.GRWG.2019.4i.2: Dave Doelling (NASA) to organise a web meeting and invite LASP to discuss on the progress for establishing a high resolution solar spectrum based on TSIS, with an estimate of the associated uncertainties. This spectrum is to be used in the VNIR activities. A.GRWG.2019.4i.3: Tom Stone (USGS) to organise a web meeting in conjunction with Seb Wagner in preparation of the next Lunar Cal workshop by the end of 2019 A.GRWG.2019.4i.4: D. Doelling (NASA) to organise a web meeting on the DCC and the preparation of a paper. A.GRWG.2019.8e.1: Rose Munro, EUMETSAT, to circulate additional ideas for new subgroup names. A.GRWG.2019.8e.2: GRWG Chair to raise the proposal to rename the UVSG to the EP.

9. Actions on GRWG from 2019 annual meeting A.GRWG.2019.9e.1: Lin Chen (CMA) and Sebastien Wagner (EUMETSAT) to specify user requirements and use cases on Level-1 data subsets over PICS and SNO prediction, and present it to GRWG in order to see if this is useful for the supporting GPRC organisations. A.GRWG.2019.9p.3: GRWG Chair to consider improving the GSICS inter-calibration coefficients because they are difficult for the user to apply these corrections. A.GEP.2019.10a.1: Mitch Goldberg (NOAA) to prepare a white paper specifying how to find the users and identify users’ need/request. A.GRWG.2019.10b.1: Scott Hu (CMA) to add one more objective in the lunar workshop that new measure (e.g. air-LUSI) can constrain the uncertainty of the lunar irradiance models. A.GEP.2019.10b.2: Mitch Goldberg (NOAA) to talk about these meeting/workshop in the coming EP meeting. A.GRWG.2019.10b.3: Scott Hu (CMA) to incorporate the comments and suggestions from the annual meeting in the report of the potential re-calibration/re-processing workshop to the EP. A.GRWG.2019.10g.1: GRWG chair to request GPRCs to present plans to develop GSICS products at 2020 annual meeting and include in template for Agency Reports. A.GWG.2019.10g.2: Mitch Goldberg (NOAA) to discuss the need for uniform GSICS monitoring pages at the Executive Panel. A.GWG.2019.10l.1: Dohyeong Kim (KMA) to plan to host GRWG/GDWG meeting in March 2020. A.GWG.2019.10l.2: OdeleCoddington (LASP) to consider hosting GRWG/GDWG in 2021.

10. Actions/Recom.sfrom CGMS46,2018 • WGII/5 A46.16: CGMS members to provide points of contacts for space weather instrument inter- calibration. (Ref. CGMS-46-GSICS-WP-01) • WGII/5 R46.01: European Space Agency to consider becoming a full member of the GSICS Executive Panel. Space Weather Task Team (SWTT) The Space Weather Task Team (SWTT) also discussed its work on inter-calibration of energetic particles using GSCIS as a methodology. SWTT discussed their current work and collaboration with GSICS and the desire to continue. SWTT noted the need for members to identify POCs on Space Weather that could assist in the inter-calibration process. SWTT also noted that activities will continue over the next year. The recent progress on applying GSICS approaches to intercalibration of space weather instruments on-board geostationary satellites was demonstrated with Himawari-8/SEDA and GOES-15 particle detectors, as also noted in the presentation by GSICS.

11. Actions from GSICS-EP-19

12. GRWG/Subgroup Web-meeting in 2018/2019

13. Plenary(Agency report, New satellites) • METOP-C : Commissioning test (IASI-C) • GOES-17 : overview of cal/val Activities, LHP Anomaly • NOAA20: The commissioning finished • GK-2A : GK2A status is under in-orbit-test . • FY-3D/FY-4A/FY-2H : Finished Commissioning test and data dissemination to outside • GCOM-C/SGLI and GOSAT-2 • NIST air-LUSI and NIST star • ROSHYDROMET IKFS-2 and MSU-GS

14. Plenary(WG report) • MWSG has grown and is still expanding. Continue to engage with other communities.  Focus on methods to characterize MW sensors. Developing best practice, for example MW SNO. Matrix of deliverable products. • IRSG focuses on hyperspectralinstruments and multispectral band instruments, and pointed out several emerging issues, including gap filling , collocation , RTM convolution. • VNIR SG has generated new SBAF, NPP-VIIRS NOAA V2 product as the GSICS official VIS/NIR Reference, Rethinking L1B calibrated radiance datasets. Lunar Calibration Status, DCC Calibration , Combine the multiple calibration approaches . • UV SG is leading the project on the ground-based characterization and A workshop is planned for Feb 2020.Proposed to re-name the sub-group as Reflective Solar Spectromenter. The main focus of the group is trace gases; the instruments are of high spectral resolution (sub-nm); and polarization

15. Special session on re-calibration/re-processing - Chair: Tim Hewison • Several projects and agencies involved in the re-calibration/reprocessing task • EUMETSAT, UK, JMA,CMA, NOAA, ESA, ECWMF • SCOPE-CM, ISCCP, FIDUCEO, CM SAF, CCI, Chinese ???? • Lots of instruments involved in re-calibration/reprocessing • GEO-Ring, HIRS, VIIRS, FY-1/3 VIRR/MERSI, FY-2/VISSR, FY-3/MWRI

16. Special session on re-cal/re-processing • FIDUCEO = systematic use of metrology principles for climate data records based on EO data. Current FCDRs: AVHRR FCDR,HIRS,MW sounders,Meteosat VIS; typical TCDRs:SurfaceTemperature,UTH, albedo + aerosol. • GEO-Ring: SCOPE-CM/IOGEO, Rob presented the summary of the methods deployed by the various participants for VIS, IR and WV calibration.  In particular there is a clear wish to pursue inter-agency collaborations. • JMA：Re-calibrating WV/IR channels of GMS/MTSAT imagers using HIRS/2, AIRS, and IASI. • Inter-calibration for climate monitoring system - collaboration with ISCCP. Knapp provided a very useful feedback on the use of GSICS data, including accessibility, ATBD usefulness, data contents and design of the GSICS websites. • NOAA S-NPP/VIIRS v2 Processing: The main difference between the v1 and v2 were presented: solar spectrum, bias correction, filters for bias corrections (Kalman filter) combining lunar cal, DCC, solar diffuser, SNOx. 

17. Special session on re-cal/re-processing • China reprocessing: CMA's recalibration/reprocessing activities. FY-1, -2, -3 reprocessing for FCDR generation for VNIR, IR and MW. Expected accuracy levels after reprocessing were listed for the various spectral regions. Rapid processing technologies are needed to support such an intensive reprocessing activity. Data record duration: 1999-2020. • O-B: Long-term calibration monitoring using UKMO NWP. Only clear sky data are kept for the analysis using RTM simulation. The satellites/instruments in scope: Met-8,9,10,11 SEVIRI, Metop-A/B IASI and HIRS, Aqua AIRS, NOAA 17 and 19 HIRS, AATSR. it is also possible to look at scan biases and scene dependences.

18. GSICS Reprocessing Activities in future • Coordinate GRWG activities to support: • FCDR generation, NWP Re-Analysis • Suggest to set up new ReCalibration Sub-Group • Pan-spectral(UV-VIS-NIR-SWIR-TIR-MW) • Independent of existing sub-groups • both hyperspectral and multispectral sensors • Sessions not to be held in parallel • Initiate an Workshop to form • 2020? Who will host the first workshop: CMA, ESA, EUMETSAT, NOAA…? • Before/after GRWG/GDWG meeting? A.GRWG.2019.10b.3: Scott Hu (CMA) to incorporate the comments and suggestions from the annual meeting in the report of the potential re-calibration/re-processing workshop to the EP.

19. GRWG (VIS/NIR-lunar calibration) • Evaluation of GCOM-C/SGLI Lunar Calibration Using GIRO • Sentinel-3 lunar acquisitions • air-LUSI: Measuring Lunar Spectral Irradiance from a High-altitude Aircraft • Update on Lunar Measurements in China • Lunar Calibration of GOES-16/17 ABI • Prototype for MTF Using the Moon + Discussion • Lunar Irradiance Measurements and Modeling Using an Aerosol Photometer • TSIS-1 total and spectral solar irradiance observations

20. GRWG (VI/NIR-sub-group)

21. IR Sub-Group products Catalog GSICS GEO-LEO IR Product Status 2019-03 Full GSICS Product Catalog available at http://www.star.nesdis.noaa.gov/smcd/GCC/ProductCatalog.php

22. IR Sub-Group overview • IR group is very active in the last year • Continued expansion of IR group • From GEO/LEO inter-calibration to GEO/GEO, LEO/LEO, other datasets • Imager/Sounder • Hyperspectral Sounder inter-calibration • Reprocessing, New Measurements, Gap Filling, Collocation • More ideas, new collaborations, exploit other ongoing activities of relevance to GSICS • Software, dataset, best practice, methods, • Sub-topical leads/formation • Develop tasks, move forward with them • References, Methods, Correction Tables, Tools … • Taking a little longer than I had hoped… • Contributions to GSICS Newsletters

23. IR Emerging Issues and Future Direction: • HyperspectralMeasurements: More hyperspectral IR instruments: IASI, AIRS, CrIS, HIRAS, GIIRS • Reference switch: IASI-A => IASI-B，SNPP CrIS => N20/CrIS • GEO and GEO Inter-calibration • Benefit for GEO-GEO inter-calibration • Collocation: Off-angle collocation; Parallax Cloud Displacement • Scene selections; Spectral match (SBAF); Instrument diurnal variation • GSICS GEO-GEO inter-calibration algorithms • Gap Filling and Convolution Errors • Encouraging CrIS data users to validate CrIS gap filling (coef. released for public) • Potential convolution errors • Gap filling IR SW bands (3.9 µm ) • PCRTM datasets • Collocation • Common issues for all inter-calibration • Collocation is fast and accurate, filtering is needed • Task forces for common collocation packages • AI &Machine Learning • AI Machining Learning and deep learning technique is emerging • NOAA workshops for AI applications (04/2019) From Xu’s Talk

24. GRWG (MW sub-group) (1/4) • 1. The calibration of newest MW sensors (NOAA-20, MetOp-C, AMSR-2, MWRI & MWRS) appear to be the best to date - newly launched sensors, agencies adopting GSICS methods. • 2. Stability of orbits in newer satellites appear to be paving the way for future references, esp. temp. sounding channels (Cheng-Zhi) • 3. Bringing closure on RTM differences may shed light on their use in DD techniques, although still needs to be some uniformity on how input data are used (i.e., we still seem to have not quite conquered filtering for clouds and other contaminants - could be a future MW group activity?) • 4. The NWP community is providing greater insight on sensor calibrations (Qifeng, Fabien, Alan, etc.), the OMB with the clear sky radiance fitting well, confirm another possible reference to evaluate and characterize the instruments.

25. GRWG (MW-sub group) (2/4) • 5. GSICS MW deliverable - X-Cal MWI calibrations. Closure is coming soon, still need to iron out content provided and whether their methods could be duplicated by other agencies, and whether actual code could be shared (a CGMS matter?) • 6. We discussed MWI constellation gap and what its impacts are (Mitch, Alan, Fabien). There are EDR's that are unique to MWI, although MWS could fill in some gaps, esp. in weather applications. There are suggestions to dive deeper in particular areas such as snow and ice • (Mitch, a new CGMS group?). It was also noted that impact studies could demonstrate more than impact at 500 mb anomaly scores - what about particular devastating storms were MWI observations were critical in storm intensity and track? • 7. GSICS MW could provide a short summary paper on impact of MWI gap and possible solutions • 8. A Strawman draft of a plan to develop inter-calibration products for microwave imagers is outlined. This is initiating the outline of the GSICS MW response to WIGOS2040 to be reported on at CGMS-47

26. GRWG (UV-sub group) • The UV sub-group session was focussing on two main areas. The first was to provide a summary of current on-going activities with a particular focus on the on-going activities at NOAA and with a second focus on reference solar irradiance spectra, paying particular consideration to the spectral aspects. Participation by OdeleCoddington (LASP) and Julian Gröbner (PMD), supporting the spectral solar irradiance discussion. • The second focus was to discuss the proposal to rename the UV sub-group to better reflect the defacto scope of the UVSG which is (inter-)calibration of UV-Vis-NIR-SWIR spectrometers. This proposal has been positively received and endorsed. This will be taken forward. The presentation by R. Munro also provided an introduction to the special session on incorporating inter-calibration of SWIR spectrometers. • The winner from the Doodle poll on renaming the UV subgroup is “Reflective Solar Spectrometer subgroup”

27. GRWG (UV-sub group) Special session on incorporating inter-calibration of SWIR spectrometers • Dave Crisp (NASA) provided an extensive and very interesting overview of the challenges and opportunities in (inter-)calibration of SWIR spectrometer. • Specific detailed points it was agreed that the inter-calibration of SWIR spectrometers would be addressed within the UVSG, also taking into account the planned renaming of the UVSG to better reflect the defacto scope of the activities. • Agreed that GSICS can make a very positive contribution to the inter-calibration of SWIR spectrometers, an area of increasing importance taking into account the increasing number of GHG missions, in-orbit, in development of planned. The group was also encouraged to raise the importance of (inter-)calibration for this class of instruments in other international fora.

28. Overview • Membership and Chairing • GRWG Activities Summary 2018/2019 • 4 Subgroups progress • Actions and Recommendations • GRWG Work Plan 2019/2020 • Webmeeting Plan • Forthcoming meeting and workshop

29. Forthcoming meeting and Workshops • An SI-Traceable Space-based Climate Observing System Workshop(CEOS, WMO-GSICS), NPL, UK, Sep 9-11, 2019 • 3rd Lunar Calibration Workshop (GSICS/IVOS): Where and when is TBD • CEOS/GSICS optical space sensor pre-flight calibration and characterization workshop is postponed to 2020. • Potential Workshop about Recalibration/Re-processing for long term Data record is being planned.

30. An SI-Traceable Space-based Climate Observing System Workshop Sponsor by (CEOS, WMO-GSICS), Local host : NPL, UK, Sep 9-11, 2019 • Formal contributions are solicited related to the following themes, which form the basis of sessions in the workshop: • Science and societal drivers for the climate and operational communities (including economic benefits) • Observations and datasets needed (measurements, timescales, and accuracies) • Reference calibrations (facilities/targets, approaches, capabilities, and uncertainties) • Mission/technologies/concepts under development or conceived (status, technical capabilities) • Develop community ‘white paper’ on benefits, needs, and a proposed implementation architecture • Pre-registration for this open workshop is required for the venue. Please submit a 300- to 500-word abstract online by March 31, 2019 at https://ceoswmogsicsworkshop.eventbrite.co.uk • Scientific Organising Committee: Nigel Fox (NPL), Bruce Wielicki (NASA), Greg Kopp (U.Colorado/LASP), Xiuqing (“Scott”) Hu (CMA), Tim Hewison (EUMETSAT)

31. Web meetings expected for next 12 months

32. Thank you