There are four GCOS atmospheric networks, the GCOS Surface Air Network (GSN), the GCOS Upper-Air Network (GUAN), the GCOS Reference Upper-Air Network (GRUAN) and the GCOS Surface Reference Network (GSRN). These networks are under the oversight of the GCOS Network Manager and by the GCOS panel. They report annually to GCOS and are represented at GCOS meetings. Detailed information and statistics for these networks can be found on the respective network pages.