1. Recommendations to GSICS from international working groups GSICS meeting, March 2015, New Delhi, India Rob Roebeling

2. GSICS Meeting, March 2014, Darmstadt, Germany Outline Introduction Requirements- Near Real-Time Committee for Earth Observation Satellites (CEOS-CGMS) EUMETSATs Data Record Generation Working Group CGMS science working groups (e.g. ICWG, IPWG)

3. GSICS Meeting, March 2014, Darmstadt, Germany Introduction Fundamental Climate Data Records (FCDR) discussion: The user community is split in opinion on the required type of re-calibration coefficients for FCDRs, which are either: Absolute re-calibrations (providing the best match to the sensors unique spectral response function) Relative re-calibrations (providing the best match to the reference sensors spectral response function) To satisfy the split opinion of the user community FCDRs should preferably provide three data representations that are internally convertible, i.e.: 1.Raw counts (original counts and associated auxiliary data/measurements) 2.Absolute radiances conversions (the best individual estimate for each sensor) 3.Relative radiances conversions (radiances have been corrected and now related to a reference sensor).

4. GSICS Meeting, March 2014, Darmstadt, Germany Requirements to GSICS - Near Real-Time - Objectives NRT: The NRT community uses re-calibrated radiances Nowcasting purposes and for assimilation into Numerical Weather Prediction (NWP) or re-analysis models. Requirement: Near-real time calibration information shall be available with a timeliness better than 5 minutes after image reception; Requirement: Quantitative information on the instrument spectral response function used for the absolute (re)calibration shall be made available with the near-real-time data; Requirement: Preference for absolute re-calibration rather than relative re-calibration (NWP and Nowcasting community); Requirement: Preference for re-calibrated radiances (better than 2%) including uncertainty estimate information (NWP community). Requirement: Re-calibrated radiances shall be provided in common file formats (e.g. BUFR, NetCDF) using internationally agreed metadata standards. Disclaimer: Based on requirements of re-analysis activity in ERACLIM

5. GSICS Meeting, March 2014, Darmstadt, Germany Requirements to GSICS - Committee for Earth Observation Satellites (CEOS-CGMS) - Objectives CGMS-CEOS: to establish an inventory of existing records of Essential Climate Variables derived from space observations, to plan the production of more CDRs and to optimize planning of future satellites to expand records and avoid data gaps. Requirement: re-calibrated time-series shoud include past/present/future instruments; Requirement: re-calibrated data from multiple instruments should be verified on consistency in overlapping regions and/or during overlapping observation periods; Requirement: time-series of re-calibrated radiances shall be regularly evaluated on temporal stability, step changes, degration, etc; Requirment: re-calibrated data should be provided with information on random errors and time-dependent biases; Requirement: re-calibrated data should be provided in common file formats (e.g. BUFR, NetCDF) using internationally agreed metadata standard. Note: CGMS-CEOS requirements are tied and reference to spatial, temporal, accuracy, and stability GCOS 2010 implementation plan (GCOS-138) and satellite supplement (GCOS-154), and the GCOS guidelines for data sets (GCOS-143). Courtesy John Bates and Pascal Lecomte

6. GSICS Meeting, March 2014, Darmstadt, Germany Requirements to GSICS - EUMETSAT’s Data Record Generation Working Group (DRG-WG) - Objectives DRG-WG: to coordinate reprocessing activities of the Satellite Application Facilities (SAFs) and the EUMETSAT Secretariat; to discuss strategies, potential for synergies and mechanism for co-operations; to address technical reprocessing aspects. Recomm’d: DRG-WG asks for FCDRs from passive imagers and microwave sounders from past/present/future missions; Recomm’d: DRG-WG encourages availability of asked FCDRs before the start of the SAFs Continued Development and Operational Phase-3 (CDOP-3) in 2018; Requirement: re-calibrated data shall included absolute re-calibation corrections, as well as inter-satellite conversion coefficients including uncertainty estimates; Requirement: re-calibrated radiances shall be evaluated on spatial uniformity and spatial accuracy of the uncertainty estimates. Especially when data records is based on multiple missions and systematic viewing geometry variations. Note: Draft requirements based on personal communication with DRG-WG co-chairs (R. Hollemann and K. Holmlund) and secretary (R. Roebeling)

7. GSICS Meeting, March 2014, Darmstadt, Germany Recommendations to GSICS - International Clouds Working Group - Recom’d: ICWG acknowledges GSICS’s efforts to calibrate infrared (IR) and water vapour (WV) channels, and recommends cloud product providers of to use the IR and WV recalibrations from GSICS for their quantitative retrievals from passive imagers. Recom’d: ICWG confirms the need for accurate calibration of the visible (VIS) and near- infrared (NIR) channels of passive images (2-3%), and stresses the importance of providing these calibrations for the current and the heritage instruments (e.g. MVIRI, SEVIRI, AVHRR, MODIS, VISSR, IMAGER, VIIRS..). Courtesy Bryan Baum and Rob Roebeling (ICWG co-chairs)

8. Thank You Questions and Answers