The Global Climate Observing System (GCOS) Reference Upper-Air Network (GRUAN) is an international reference observing network, designed to fill an important gap in the current global observing system. GRUAN measurements will provide long-term, high-quality climate data records from the surface, through the troposphere, and into the stratosphere. These will be used to determine trends, constrain and calibrate data from more spatially‐comprehensive observing systems (including satellites and current radiosonde networks), and provide appropriate data for studying atmospheric processes. GRUAN is envisaged as a global network of eventually 30-40 sites that, to the extent possible, builds on existing observational networks and capabilities.

Status of GRUAN stations

GRUAN is envisaged as a global network of eventually 30-40 measurement sites. To the extent possible, it builds on existing observational networks and capabilities. At the end of 2016, GRUAN comprises of 22 stations, 9 of which have passed the GRUAN certification process.

Status of data flow

A comprehensive volume of measurement data has been collected by GRUAN since about 9 years. The archive includes raw data and related meta-data. For the Vaisala RS92 radiosonde, the first GRUAN data product (GDP) is fully implemented and available since 2012. Further data products (GDP) are under development.

Structure of website

Network

Information about organisation and parts of network

Data

Information about data, data handling and data products

Instruments

Information about instruments used at GRUAN stations

Documentation

Archive of and information about GRUAN-related documents

Community

Collection of all community tools

About GRUAN

Why do we need GRUAN?