Upper-air observations for climate: Rationale, progress, and plans for the GCOS Reference Upper-Air Network

(GRUAN)

Dian Seidel, Howard Diamond, David Goodrich, NOAAPeter Thorne, Met Office

AMS 25th Conference on International Interactive Information and Processing Systems (IIPS)for Meteorology, Oceanography, and Hydrology --- J5.1 15 January 2009 – Phoenix, AZ

• The who, what, where, when, why and how of GRUAN … in brief

• Related article to appear in March 2009 BAMS• Contributions from many GRUAN colleagues• Take home message:

After more than a decade of discussion, a GCOS Reference Upper Air Network, to provide climate-quality measurements of tropospheric and lower stratospheric variables, is starting to become a reality.

What is GRUAN?

• An international reference observing network• Designed to meet unmet climate requirements• Measuring GCOS “Essential Climate Variables”

Why do we need GRUAN?• Provide long-term, high quality upper-air climate

records, with complete estimates of measurement error

• 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

Why do we need GRUAN?

Why do we need GRUAN?

Who will steer, manage, and operate GRUAN?

Who … the org. chart

Working Group on Atmospheric Reference Observationguides development of GRUANrecommends to AOPCsite selectionguidelines for observations, data diss.

Chair: Peter Thorne

GRUAN Lead Centremaking GRUAN happennetwork management

Head: Holger Vömel

GCOS Secretariatsupport to ARO, AOPC, GCOS Steering Comm.connective tissue

Director: Alexander Karpov

GCOS Steering CommitteeChair: John Zillman

Atmospheric Observation Panel for Climate (AOPC)Chair: Adrian Simmons

WMOGCOS co-sponsorLead Centre designation

Who … key partners

• National contributors (incl. US)• WCRP and the climate science community• Other monitoring networks, e.g.– Network for the Detection of Atmospheric Composition

Change– Baseline Surface Radiation Network• Global Space-based Inter-Calibration System• WMO - CIMO and CBS; Observations Department• NMS international departments, development

agencies

Where will GRUAN stations be?

What observations will be madeat GRUAN sites?

How will GRUAN observations be archived, disseminated, and used?

• GRUAN Data Center– distributed functions– built on existing capabilities at DWD, NOAA, DOE

• Ensure the early, ongoing and widespread use of GRUAN observations.

• Focus efforts on – characterizing observational error– improving satellite data products– understanding climate variability and change.

When will GRUAN measurements end?

• Continue as long as there is a need for in situ reference atmospheric profile observations for climate

• Several decades, at least• Until satellite (or other) observations can be

independently and unambiguously calibrated to international standards

More questions?Check out www.gruan.org