The GCOS Reference Upper Air Network (GRUAN): creating an

Arctic/Antarctic mirrorGreg Bodeker

GRUAN co-chairAntarctica New Zealand Annual Science Conference 2012

4 October 2012Christchurch, New Zealand

Presentation available at http://www.bodekerscientific.com/presentations

First something about GRUAN

From: Santer et al., Consistency of modelled and observed temperature trends in the tropical troposphere, International Journal of Climatology, DOI: 10.1002/joc.1756, 2008.

The problemHistorical observations made primarily for operational monitoring purposes.

Ubiquitous change - impacts very rarely adequately quantified for climate trend determination.

Ambiguity in the rate and details of climatic changes.

Significant impediment to understanding climate change and its causes.

The solutionThe GCOS Reference Upper Air Network (GRUAN)

Network for ground-based reference observations for climate in the free atmosphere in the frame of GCOS

Initially 15 stations, envisaged to be a network of 30-40 sites across the globe when GRUAN becomes fully operational. See www.gruan.org for more

detail

GRUAN sites

Currently no sites in South America, Africa or Antarctica. Only one south of 12.5°S.GRUAN Network Expansion Workshop held in June 2012, in Berlin.

GRUAN governance Notes1.WCRP identifies

scientific and research requirements for GRUAN. WMO identifies operational requirements.

2.Composition of WG-GRUAN determined by Chair of AOPC in consultation with WMO. Includes representative from each of CIMO, CBS, CAS and CCl.

3.WG-GRUAN reports to AOPC

4.GRUAN measurement sites are contributed by member countries of WMO.

GCOS SC#3

Measurement Sites#4

Lead CentreTask and Analysis Teams

WG-GRUAN#2

ICSU

Guidance

GRUAN

Reporting

Reporting Guidance

WMO#1IOCUNEP

AOPC

CIMO/CBS/CAS/CCl

ReportingGuidance on specific issues

Guidance on Operational

Requirements for GRUAN

(GRUAN & WIGOS Manual)

WCRP#1

Guidance on Science/Research

Requirements for GRUAN

Reporting

The goals of GRUANThe purpose of GRUAN is to:• Provide long-term high quality climate records;• Constrain and calibrate data from more spatially-

comprehensive global observing systems (including satellites and current radiosonde networks); and

• Fully characterize the properties of the atmospheric column.

Four key user groups of GRUAN data products are identified:

• The climate detection and attribution community.• The satellite community.• The atmospheric process studies community.• The numerical weather prediction (NWP) community.

More about goals of GRUANMulti-decade measurement programmes.

Characterize observational biases.

Robust, traceable estimates of measurement uncertainty.

Ensure traceability through comprehensive meta-data collection and documentation.

Ensure long-term stability by managing measurement system changes.

Tie measurements to SI units or internationally accepted standards.

Measure a large suite of co-related climate variables with deliberate measurement redundancy

Priority 1: Temperature, pressure, water vapourPriority 2: Ozone, methane …

Establishing reference quality

Uncertainty, redundancy and consistency

Understand the uncertainties: Analyze sources - identify, which sources of measurement uncertainty are systematic (calibration, radiation errors), and which are random (noise, production variability …). Document this.

Synthesize best uncertainty estimate: Uncertainties for every data point, i.e. vertically resolved

Use redundant observations:to manage changeto maintain homogeneity of observations across networkto continuously identify deficiencies

The GRUAN LeadCentre, Lindenberg

Free University of Berlin

AWI, Potsdam

GRUAN LC, FUB and AWI all in the greater Berlin area

Proposed GRUAN site, Ny Alesund

(78.9oN)

Mirror

Lauder GRUAN site

University of Otago/Canterbury

?

Antarctica New Zealand/NZARI?

Scott Base/Arrival Heights (77.9oS)?

What’s to be gained?Can we establish this as a nucleus for atmospheric climate research in New Zealand?Between the Lead Centre, FUB and AWI, considerable momentum is building around the implementation of GRUAN. New Zealand stands to gain a lot by tapping into this growing centre of excellence.New Zealand already has close ties to the Lead Centre. I spend 20% of my time on GRUAN activities and visit the Lead Centre annually.We have close working ties with the Institute for Meteorology at FUB. I am a formal collaborator on the SHARP project.We have close working ties with AWI. Steady flow of DAAD funded PhD students and work experience students.Visiting academics. Markus Rex (AWI) has a working visit to Canterbury University and BS from mid-February to end of April next year.New Zealand playing a key role in the establishment of a state-of-the-art global climate monitoring network.Sharing of skills and expertise would be primarily a one way flow into New Zealand.