1. Implementation of the GCOS Reference Upper-Air Network (GRUAN) WOAP-IV Hamburg, Germany, March 2010

2. What is GRUAN?  Reference Upper-Air Network for ground based climate observation of the free atmosphere in the frame of GCOS  Currently largely an abstract concept - to be implemented within the next years  Eventually ~30 - 40 sites across the globe (currently 15)  Serving to constrain and calibrate data from more spatially-comprehensive global observing systems (inc. satellites)  Providing long-term, high-quality climate records of upper-air variables („GCOS essential variables”) – Upper-air temperature (including MSU radiances) – Water vapour – Wind speed and direction – Cloud properties – Earth radiation budget (including solar irradiance) – Others

3. GRUAN aims to  Provide long-term, high quality upper-air climate records, with complete estimates of measurement accuracy  Fully characterize the properties of the atmospheric column and their changes  Constrain and adjust data from more spatially comprehensive global observing systems (including satellites and current radiosonde networks)  Ensure that potential gaps in satellite programs do not invalidate the long-term climate record  Building on, and augmenting, existing WMO networks, e.g. GUAN Cascade of Networks

4. Key scientific questions to be addressed by the GRUAN  Characterization of changes in temperature, humidity, and wind, using current operational radiosonde capabilities  Understanding the climatology and variability of water vapour, particularly in the UTLS, as well as changes in the hydrological cycle  Understanding and monitoring tropopause characteristics  Understanding the vertical profile of temperature trends  Bringing closure to the Earth’s radiation budget and balance  Understanding climate processes and improving climate models

5. Milestones achieved so far  Designation of a GRUAN Lead Centre at the Lindenberg Observatory (Germany)  Definition of major requirements for reference observations and what will constitute a formal GRUAN measurement  Appointment of initial GRUAN stations  Publication of the GRUAN Implementation Plan 2009-2013 (GCOS-134)  Annual Implementation- Coordination Meetings  Appointment of Task Teams  First GRUAN-quality data expected in 2010

6. 2 nd Implementation-Coordination Meeting (ICM-2), March 2010 Designation of Task Teams:  Team 1: Radiosondes evaluate the data products (uncertainty budget etc.) and bring in missing knowledge (from operational sites)  Team 2: GPS-PW draw conclusions on the suitability of the deployed equipment  Team 3: Measurement schedules and associated site requirements develop defensible, quantifiable, scientifically-sound guidance  Team 4: Site assessment, expansion and certification define assessment criteria for sites and provide regular assessments  Team 5: Ancillary measurements initial focus on MWR, Lidars and FTIR; interface with satellite experts and NDACC  GRUAN Science Team (GATNDOR)  Site Team representing GRUAN sites

7. GRUAN Task Teams WOAP involvement would be highly valuable! Please consider and in case of interest contact Peter Thorne, chairman of WG-ARO: peter.thorne@metoffice.gov.uk

8. Contact Information GRUAN Lead Centre Deutscher Wetterdienst Richard-Assmann Observatory Lindenberg Am Observatorium 12 D-15848 Tauche, Germany Tel.: +49 33677 60-244 E-mail: GRUAN.LC@dwd.de Web: http://www.dwd.de/mol Thank you

9. Best practice to ensure reference quality measurements From Immler et al., submitted to Atmos. Meas. Techn.

10. Traceability Chain From Immler et al., submitted to Atmos. Meas. Techn.

11. Why do we need GRUAN?  Changes in tropospheric temperatures are very poorly constrained  Changes in humidity are understood even less, especially in the radiatively important upper troposphere  Changes in other variables are generally worse still  Primary reason: current observations were never made for climate research Historical upper-air records are not as good as required for studying climate change We need a way of separating the true signal from the inevitable non-climatic effects that will be imparted into the record!

12. GRUAN data management

13. Time line of next steps – 1  April 2010 A “Data Collecting Guide” send to all stations (version 0.9) → Radiosonde Test of data flow to lead centre Test of pre-processing (semi-automatic testing, converting, meta-data analysis)  May / June 2010 Start of operational data collection (including meta-data) Test of data flow to processing hosts (ARM – RS92, …) Test of uncertainty quantification for RS92  July 2010 Test of data flow to dissemination host (NCDC) Clarify the problemswithin our data flow(station, hosts, lead centre)

14. Time line of next steps – 2  August 2010 Start of operational (automatic) data flow Collecting + Pre-Processing + Archiving + Processing + Dissemination  full → RS92  partly (min. collecting) → CFH, SRS-400, GTS-1, FLASH, …  October to December 2010 Include additional measurements → surface reference, GPS-IWV, … Test of reporting system → issues, bugs  January / February 2011 Start of advanced test phase (beta) of reporting system Test of meta-data management (free tool for the sites)

15. Conclusion → at ICM-3 we have:  Operational data flow of priority 1  Reporting system (on web site, beta-phase with version <1.0)  Tool for meta data management (alpha- phase with version <0.5) Editor for launch meta-data Maintenance of station meta-data  Monitoring system (on web site, alpha- phase with version 0.1) View of current status of measurements & processing

16. The concept  National contributors (Fundamental to success of the enterprise)  WCRP and the climate science community  Global Space-based Inter- calibration System (GSICS)  Existing observational networks (NDACC, ARM, GUAN, GAW, BSRN, GSN,...)  WMO - Commissions: CIMO and CBS - Observations Department / WIGOS  NMS international departments, development agencies Partners

17. GRUAN Data Management Effort Data Management Planning Meeting held at NCDC in Sep 2009 Participants GRUAN Lead Center [Lindenberg] U.S. Department of Energy’s ACRF Program NOAA’s National Climatic Data Center Intent: To develop a way forward for the activities necessary to manage GRUAN data in the following areas: Data archiving capabilities at NCDC and ARM Capabilities of the Meta-database (located at the lead center) Development of a data dissemination portal that links the Meta-database and the GRUAN data archive with the data users The role of NCDC and ARM in radiosonde QA/QC Organizing data flows from the GRUAN sites, through a QA/QC institution to the GRUAN data archive. All slides and meeting report are posted at the following FTP site at ftp://dossier.ogp.noaa.gov/GCOS/GRUAN-DM-Meeting/