1. Analysis of free tropospheric humidity within CM SAF
Marc Schröder (CM SAF/DWD)
Thanks to:
R. Roca, J. Meier-Fofana, N. Gif (LMD)
A. Kniffka (CM SAF/DWD)
C. Standfuss (Noveltis)
GSICS User Workshop, 2012

2. Overview
Free tropospheric humidity (FTH) climate data record available from CM SAF:
Methods
Evaluation
Development of a geo-ring FTH product for SCOPE-CM.
GSICS User Workshop, 2012

3. FTH from Meteosat
FTH covering the years within 45°N/S/E/W using homogenised
METEOSAT observations (MET2-5, 7-9) (3-hourlies and monthly averages, 0.625°).
Release in Nov
ISCCP cloud mask (full period) and radiances (until June 2006).
Achieved within a research and operations activity between LMD/CNRS and CM SAF.
Future: Use Meteosat FCDR, CM SAF cloud mask (MeteoSwiss, DWD), increase
spatial and temporal resolution.
DJF JJA
GSICS User Workshop, 2012

4. FTH from Meteosat
Inversion from brightness temperatures (BT) to FTH follows
Soden and Bretherton (1993):
Homogenisation follows Picon et al. (2003):
Spectral response functions adapted and time series inter-calibrated to HIRS (Breon et
al., 2000, Roca et al., 2012).
Compare to ARSA (Analysed Radio Soundings Archive, from ARA-LMD) as input to RTTOV (from NWP SAF), simulate METEOSAT observations at 6.3 microns and integrate using Jacobians.
Further comparisons to UTH from HIRS (NOAA/NESDIS/NCDC) and AMSU-B (UKMO, LTU).
GSICS User Workshop, 2012

5. Homogenisation Homogenised clear sky radiance time series.
Homogenisation at:
Dec 2000 / Jan 2001
MET7 / MET8
MET8 / MET9
to meet requirements in FTH space
(0.26%/dec - 2%/dec).
The need for homogenisation became evident only when looking at stability in product space.
bias = 0.1 K
RMS = 1.2 K
Preliminary result
GSICS User Workshop, 2012

6. Courtesy of Joerg Schulz, adapted
SCOPE-CM
SCOPE-CM: Sustained co-ordinated processing of environmental satellite data for climate monitoring.
Objective: continuous and sustained provision of high-quality Essential Climate Variables satellite products (Climate Data Records) on a global scale
Structure: The SCOPE-CM Network will be:
Based on activities of existing initiatives (GOS, GCOS and GSICS)
Build upon existing operational infrastructures
Serve users and other organisations (e.g. WMO Regional Climate Centres RCC, National Weather Services)
Courtesy of Joerg Schulz, adapted
GSICS User Workshop, 2012

7. Geo-ring FTH demonstrator
Rely on existing data (ISCCP-B3, ISCCP-DX, GSICS).
Adapt SRF of each geo to common reference channel (see GSICS, 2010 and Fig.).
Recompute regression coefficients for CRC.
±45°N/S all longitudes, 3-hourly, 1 month, 30 km or 0.625°.
Aim at the generation of a consistent and global FTH/UTH product using data from
geostationary and polar-orbiting satellites.
First planning meeting at 28 Sep 2012 at CM SAF/DWD together with
NOAA/NESDIS/NCDC and UKMO.
Hewison and Kessel, 2010
GSICS User Workshop, 2012

8. Summary
User feedback
Reprocessing of (geostationary) satellite archives.
Detailed analysis at suspicious periods / known issues.
Rethink common reference channel approach and service.
Consider/seek feedback from quality control in product space.
GSICS User Workshop, 2012

9. DWD/CM SAF, Offenbach, Germany
Assessment
GEWEX water vapor assessment project under the framework of WCRP-
GEWEX, co-chaired by NOAA/NESDIS/STAR, NOAA/NESDIS/NCDC and CM
SAF /DWD. Objective (among others):
Characterise the quality of water vapour records through sound validation
against validation data base.
DWD/CM SAF, Offenbach, Germany
26-28 September 2012
TCWV (Mieruch et al., 2011) UTH (Shi and Bates, 2011) Profiles (Stengel et al., 2012)
GSICS User Workshop, 2012

10. Thanks for your attention!
GSICS User Workshop, 2012