Implementation of the GCOS Reference

Upper-Air Network (GRUAN)

WOAP-IVHamburg, Germany, March 2010

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

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

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

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

2nd 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

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

Contact Information

GRUAN Lead Centre Deutscher Wetterdienst

Richard-Assmann Observatory Lindenberg Am Observatorium 12

D-15848 Tauche, GermanyTel.: +49 33677 60-244

E-mail: GRUAN.LC@dwd.de Web: http://www.dwd.de/mol

Thank you

Best practice to ensure reference quality measurements

From Immler et al., submitted to Atmos. Meas. Techn.

Traceability Chain

From Immler et al., submitted to Atmos. Meas. Techn.

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!

GRUAN data management

Time line of next steps – 1

April 2010A “Data Collecting Guide” send to all stations (version 0.9)

→ RadiosondeTest of data flow to lead centreTest of pre-processing

(semi-automatic testing, converting, meta-data analysis)

May / June 2010Start of operational data collection (including meta-data)Test of data flow to processing hosts (ARM – RS92, …)Test of uncertainty quantification for RS92

July 2010Test of data flow to dissemination host (NCDC)

Clarify th

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sw

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r data flo

w(station, hosts, lead centre)

Time line of next steps – 2

August 2010Start 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 2010Include additional measurements → surface reference, GPS-

IWV, …Test of reporting system → issues, bugs

January / February 2011Start of advanced test phase (beta) of reporting systemTest of meta-data management (free tool for the sites)

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-dataMaintenance of station meta-data

Monitoring system (on web site, alpha-phase with version 0.1)View of current status of measurements & processing

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

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/