The Atmospheric Radiation Measurement (ARM) Climate Research Facility is a multi-laboratory, U. S. Department of Energy (DOE) scientific user facility, and a key contributor to national and international earth system research efforts. ARM was the first atmospheric research program to deploy a comprehensive suite of cutting-edge instruments to continually measure cloud and aerosol properties and their impacts on Earth’s energy balance. This strategy revolutionized scientists’ ability to collect long-term statistics of detailed cloud properties and now serves as a model for similar programs around the world. ARM provides: • Data – Access more than 25 years of atmospheric data gathered during normal operations and field campaigns • Observatories – Use heavily instrumented fixed-location atmospheric observatories in Oklahoma, Alaska, and the Azores, including aerial (manned and unmanned) and mobile facilities • Instruments – Explore close to 400 instruments that collect data at locales spanning diverse meteorological regimes • Campaigns – Conduct atmospheric science in strategic locations around the world • Models – Retrieve large-eddy simulation modeling data, simulations, and analysis tools • Publications – Discover ARM-related research on clouds and aerosols, their interaction with the Earth’s energy balance, and representation in earth system models.