1. GRAS-SAF User Workshop June 2003 1 The H umidity C omposite P roduct of the CM-SAF Helga Nitsche Deutscher Wetterdienst, D-63067 Offenbach Content: The CM-SAF (short overview) The HCP: product definition and specification Validation of Input Data Gridding and Interpolation „Merging“ of satellite-derived precipitable water: the concept User Requirements for HCP User Requirements of HCP for GRAS-SAF

2. GRAS-SAF User Workshop June 2003 2 The H umidity C omposite P roduct of the CM-SAF The CM-SAF: Overview 5 Scientific Work Packages Products connected to the Energy and Water Budget of the Earth Regional Products Product Groups: Cloud Parameters Surface Radiation TOA fluxes Surface Ocean Stress Humidity Composite Product

3. GRAS-SAF User Workshop June 2003 3 The H umidity C omposite P roduct of the CM-SAF The CM-SAF: The Products

4. GRAS-SAF User Workshop June 2003 4 The H umidity C omposite P roduct of the CM-SAF The CM-SAF: The Processing Area

5. GRAS-SAF User Workshop June 2003 5 The H umidity C omposite P roduct of the CM-SAF The HCP: Productdefinition an independent water vapour profile data set based on merged satellite products only validated with sophisticated in-situ observations

6. GRAS-SAF User Workshop June 2003 6 Precipitable water; total column and Layers between pressure levels Physical units: g/kg resp. mm Spatial resolution: = 3 layers (5-6) Temporal resolution: daily, monthly Meta data: Input data sources, QC-Flags, Validation results, Merging Algorithm First operational product: July 2005 Duration: Operational long term product The H umidity C omposite P roduct of the CM-SAF Productspecification:

7. GRAS-SAF User Workshop June 2003 7 The H umidity C omposite P roduct of the CM-SAF

8. GRAS-SAF User Workshop June 2003 8 The H umidity C omposite P roduct of the CM-SAF Validation Topics:

9. GRAS-SAF User Workshop June 2003 9 The H umidity C omposite P roduct of the CM-SAF Validation Data: operational Networks:

10. GRAS-SAF User Workshop June 2003 10 The H umidity C omposite P roduct of the CM-SAF Validation Data: Reference Stations: Instrumentation:

11. GRAS-SAF User Workshop June 2003 11 The H umidity C omposite P roduct of the CM-SAF Gridding and Interpolation:

12. GRAS-SAF User Workshop June 2003 12 The H umidity C omposite P roduct of the CM-SAF Spatial and Temporal Resolution of Input:

13. GRAS-SAF User Workshop June 2003 13 The H umidity C omposite P roduct of the CM-SAF Merging: Applicable models: 1) NVaP (NASAWater Vapour Programme), Randel et.al. 2) GPCC Huffman et.al. Basic Idea: Daily mean values on the Grid from Interpolation for the polar orbiter satellites (ATOVS-data from NOAA, METOP) Bias Correction for TPW, biases from Validation Profile Information from ATOVS, IASI: relative profiles (%) improve horizontal resolution by SEVIRI improve daily mean by SEVIRI extension to Upper Troposphere/Lower Stratosphere with GRAS perhaps additional constraints: DEM und TRP

14. GRAS-SAF User Workshop June 2003 14 The H umidity C omposite P roduct of the CM-SAF User Requirements for HCP Horizontal spatial resolution: < 10.... 5000 km vertical resolution: 3-8 Layers time resolution: </= 1/h...1/d parameters: precipitable water (& absolute/specific humidity) area extension to MSG: yes area extenstion to inner arctic circle: no/yes accuracy: </= 10 % (</=5 %)

15. GRAS-SAF User Workshop June 2003 15 The H umidity C omposite P roduct of the CM-SAF User Requirements for HCP Possible Applications Reference Data Set Background Data Set for Numerical Modeling Validation Purposes Process Studies Input into Climate Monitoring Products

16. GRAS-SAF User Workshop June 2003 16 The H umidity C omposite P roduct of the CM-SAF User Requirements of HCP for GRAS-SAF Vertical Extent: at least up to the Lower Stratosphere Metadata: extensive Metadata together with each Profile, including Time of Measurement, Horizontal Representativeness, Reliability/Representativeness of the Lowest Level, method/model used for the retrieval Reprocessing Capability? Unlimited Archive of the Measurements and Metadata individual profiles highest possible absolute accuracy

17. GRAS-SAF User Workshop June 2003 17 The H umidity C omposite P roduct of the CM-SAF Vertical Profiles of Precipitable Water