CGMS-42 Working Group II Report Co-Chairs: Toshiyuki Kurino, JMA, and Lars Peter Riishojgaard, WMO Rapporteurs: Ajay Mehta, NOAA and Johannes Schmetz, EUMETSAT 1

Working Group II Highlights More than 50 papers Reports from all four International Science Working Groups, ITWG, IWWG, IROWG, IPWG Recommendation about the formation of a fifth ISWG, the International Clouds Working Group Between 40 and 50 people in attendance Generally good progress on actions 2

WGII/2 Image processing techniques and satellite imagery for nowcasting Action WGII CGMS42.xx: NOAA is invited to present a paper to CGMS 43 on the level-1 (geometric and radiometric) data processing of the DNB. Action WGII CGMS42.xx: NOAA to present a paper on quantitative applications of the DNB including validation activities as applicable. 3

WGII/3 Satellite data calibration and validation including climate related aspects Recommendation WG II CGMS 42.xx: GSICS to explore the utility of images affected by shortcomings of instruments (e.g. solar straylight) and draft a recommendation on the use of such data in the reprocessing. Action WG II CGMS 42.xx: EUM/NOAA/NASA/JMA/CMA/WMO and others to provide names for a task team on calibration events logging. Action CGMS 42.xx: The new task team on calibration events logging to identify a common set of parameters to be monitored as part of the calibration events logging and sensor performance monitoring. WG II expressed deep thanks and appreciation for the work of the outgoing Chair of the GSICS Executive Panel Dr. Mitch Goldberg, NOAA, and welcomed the new Chair Dr. Peng Zhang of CMA. 4

WG II/4 Infrared/microwave sounding and ITWG Matters Top Recommendations from ITSC-19: To CGMS and satellite agencies: The constellation of at least three orbits (early morning, morning, and afternoon), each with full sounding capabilities (IR and MW), should be maintained. The overpass times of operational satellites with sounding capability (IR and MW) should be coordinated between agencies to maximize their value. To CGMS and satellite agencies: conduct studies to trade off benefits of spectral, radiometric, and spatial resolutions of infra-red sounders considering the noise floor due to atmospheric noise and current uncertainties in spectroscopy, to enable improved spatial resolution and increased number of field of views for the next generation hyperspectral infra-red sounders. To satellite agencies: noting that absolute calibration with on-orbit SI traceability is critical for significantly reducing uncertainties in monitoring climate trends, ITWG recommends to pursue the realization of absolute calibration missions (such as CLARREO), including considering flight opportunities on the ISS. To CGMS: ITWG supports low-cost fast delivery initiatives such as RARS, and recommends reactivating the RARS Implementation Group within WMO with a broader scope to include the NOAA Direct Broadcast Real Time Network (DBRTN) and to include CrIS, IASI, ATMS, and other sounder data. 5

6 Significantly improved precipitation forecasts when data from three-orbit constellation used Slide courtesy of NOAA Significantly improved precipitation forecasts when data from three-orbit constellation used Slide courtesy of NOAA

WG II/4 Infrared/microwave sounding and ITWG Matters Top Recommendations from ITSC-19 (II): To Roshydromet: pre-processing software for L0/L1 Meteor-M data should be made available to interested users. To IRC, CGMS and satellite agencies: Support for line-by-line (LBL) reference model development is of paramount importance and should be continued to ensure that users (in both operational and non-operational institutions) have access to the latest updates in LBL forward modelling. To IRC, CGMS and satellite agencies: encourage validation and intercomparison of LBL models/spectroscopy to assess the impact of spectroscopic uncertainties and the differences between line-by-line and fast radiative transfer models. 7

WG II/4 Infrared/microwave sounding and ITWG Matters Top Recommendations from ITSC-19 (III): To satellite agencies: instrument characteristics should be provided as early as possible (even approximate versions) to allow preparations for radiative transfer modelling and other evaluations. This includes in particular spectral response functions. Ultimately, detailed digitised channel system responses should be made available to allow the best-possible radiative transfer calculations. To satellite agencies: ITWG recommends open access to new satellite data during the calibration/validation phase (particularly for all NWP centres) to help with calibration and validation. To CGMS and satellite agencies: conduct intercomparison studies between level 2 retrievals from hyperspectral instruments, recognising that there are now several software packages available that utilize IASI/CrIS/AIRS data for the generation of level 2 products. 8

(4) Forecast Sensitivity to Observations (FSO) (5) Soil moisture impact on NWP (ongoing work) -SMOS, GCOM-W1, ASCAT Total impact of each satellite (a) and total impact of each sensor in MetOp (A/B) satellite (b) from UTC to UTC (J/kg) AMSU-A sensor gives the largest impact (~42%), followed by IASI (19%) and IR of AMV (12%) Total impact of each observation sub-type on the operational global NWP for the period from UTC to UTC 9 Significant impact on NWP skill of soil moisture observations Slide courtesy of KMA Significant impact on NWP skill of soil moisture observations Slide courtesy of KMA

WG II/4 Infrared/microwave sounding and ITWG Matters Recommendation WG II, CGMS 42: All ISWGs under CGMS to establish a formal interaction with Joint CEOS- CGMS Working Group on Climate. Action WG II CGMS 42.xx: KMA is invited to present a paper of different sources of soil moisture retrieval on their NWP forecasts. Due date CGMS 43. WG II acknowedged the contributions of Prof. H.J. Bolle, a co- founder of the ITWG, to the formation and progress of ITWG (ITSC). Prof. H.J. Bolle passed away last year. 10

WGII/6 Atmospheric motion vectors and IWWG matters Recommendation WG II CGMS 42.xx: CGMS recommends to CGMS members performing a reprocessing of AMVs to pursue future AMV reprocessing with their own algorithm and in addition with a common algorithm. IWW12 is invited to discuss the implications and derive guidance on the practical implementations. 11

WGII/7 Radio occultation and IROWG matters Main Recommendations IROWG-3 to CGMS: Develop a detailed GNSS-RO Continuity Plan Move towards a fully operational GNSS RO constellation providing at least 10,000 observations per day Ensure the continuity of RO measurements Avoid an impending observation gap at mid- and high latitudes Fund the FORMOSAT-7/COSMIC-2 Polar mission Missions should enable receiver firmware updates to maximize receiver performance Hold an interagency workshop to define cooperation options for LEO-LEO occultation research 12

‹#›CGMS-42 WGIII/2.2 EUM-WP-34 Preliminary Study Results: Comparison Global temperature improvements for different RO observing scenario against one with no RO instrument available. Scenarios shown: sc08: EPS-SG A1,B1; C2-E sc09: EPS-SG A1,B1; C2-E; C2-P sc11: EPS-SG A1,B1; C2-E; RO-N; RO-EM noro: No RO instrument assimilated 13 No saturation of NWP error reduction evident even with GPS occultations per day Slide courtesy of EUMETSAT No saturation of NWP error reduction evident even with GPS occultations per day Slide courtesy of EUMETSAT

WGII/7 Radio occultation and IROWG matters (II) Action WG II, CGMS 42. xx: CMA is invited to present a paper to CGMS-43 on prospects of RO measurements with future FY-3 satellites. 14

WGII/8 Cloud and ash/dust related matters, including proposal for a new CGMS International Science Working Group Action WG II, CGMS42.xx: CMA to present a paper on their approach toward multi-sensor aerosol products. Recommendation WG II of CGMS 42 to Plenary: CGMS 42 plenary is invited to accept the formation of an International Clouds Working Group (ICWG) under CGMS on the basis of the Terms of References presented to and confirmed by WG II of CGMS 42. If accepted => Action CGMS 42.xx: Co-chairs of the International Cloud Working Group (ICWG) to develop the new ICWG into a structure which is common to the existing International Science Working Group under CGMS and provide a report to CGMS

WGII/9 Ocean parameters ACTION WG II. CGMS42. Xx: JAXA is invited to explore possibilities to adjust to GCOM-C1 orbit in order to optimise the misson with Sentinel-3 (reference is CGMS-42-NASA-WP-02). Due date CGMS

WGII/10 Other Parameters Action WG II, CGMS 42.xx: WMO is invited to provide a report to CGMS-43 on the outcome of the work of the Global Atmospheric Watch (GAW) Task Team on Observational Requirements. Action WG II, CGMS 42.xx: IWW12 and IPWGx (next session) to respond to the updated HLPP and to provide feedback to the CGMS Secretariat within 3 months after the working group meeting. 17

WG II/12 Any Other Business Recommendation WG II, CGMS42.xx: WG II discussed options to provide sustained financial support to the conduct of the International Science Working Groups under CGMS. Although the benefit of establishing a recurrent trust fund was acknowledged, it was concluded that the current approach that relies on voluntary contributions (money or in kind) has worked quite well and should be continued. However CGMS members are kindly reminded that contributions on a voluntary basis are necessary and encouraged. 18