Development of the GUAN

The criteria for selection of the GUAN stations  included (1) station location (as homogeneously distributed as possible); (2) station reliability; (3) length of record at the station. AOPC used the performance records of existing World Weather Watch GOS stations and station quality information from the Lead Centre quality monitoring programme of the WMO Commission on Basic Systems (CBS).

The Rapporteur on GCOS and the Working Group on Observations (WGO) reviewed the proposed GUAN from a feasibility point of view. The Rapporteur on Regional Aspects of the GOS, the Chairman of the WMO Executive Council Working Group on Antarctic Meteorology, the CBS Rapporteur on Upper Air Observations, and the Representative on the Working Group on Observation of the CBS Lead Centre for Radiosonde Data also reviewed the proposed network. Additionally, the list of prospective stations was sent to concerned WMO Members for comment. The responses received were incorporated in a final version of the report to the WGO. The WGO resolved the proposed network as amended and updated was a feasible initial step towards the establishment of the GUAN.

Having developed a baseline upper-air network, the Panel recommended:

• The network design be presented to the WMO Commission for Basic Systems, and its Working Group on Observations, to WMO Regional Associations, and to particular countries or agencies;
• That a comprehensive approach to the data management issues associated with the baseline network be developed in partnership with the Data Management Panel.

AOPC has completed development of the GUAN and implementation is proceeding. Detailed information on the operation of the GUAN is available in publication " Guide to the GCOS Surface and Upper-Air Networks: GSN and GUAN - (Version 1.1) GCOS-73 ".