ADM: Atmospheric Dynamics Mission

AMDAR: Aircraft Meteorological Data Relay

BSRN: Baseline Surface Radiation Network

CESAR: Cabauw Experimental Site for Atmospheric Research

EG-CLIMET: European Ground-Based Observations of Essential Variables or Climate and Operational Meteorology

EARLINET: European Aerosol Research Lidar Network to Establish an Aerosol Climatology

GCOS: Global Climate Observing System

GAW: Global Atmospheric Watch

GEOSS: Global Earth Observation System of Systems

GMES: Global Monitoring for Environment and Security

GOS: Global Observing System

GPS: Global Positioning System

GRUAN: GCOS Reference Upper Air Network

GTOS: Global Terrestrial Observing System

IGOS: Integrated Global Observing Strategy

MWR: MicroWave Radiometer

MWRnet: An international network of MicroWave Radiometers

TOPROF: Towards Operational ground-based PROFiling with ceilometers, doppler lidars and microwave radiometers

UNEP: United Nations Environment Programme

UNFCCC: United Nations Framework Convention on Climate Change

WIGOS: WMO Integrated Global Observing System of Systems

WMO: World Meteorological Organization