About ARM

Road to Cerro Toco
Road to Cerro Toco


The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE) to develop several highly instrumented ground stations to study cloud formation processes and their influence on radiative transfer. This scientific infrastructure now includes two mobile facilities, an aerial facility, and data archive available for use by scientists worldwide through the ARM Climate Research Facility—a scientific user facility.

Sponsored by DOE's Office of Science and managed by the Office of Biological and Environmental Research, ARM is a multi-laboratory, interagency program, and is a key contributor to national and international research efforts related to global climate change. This user facility has enormous potential to advance scientific knowledge in a wide range of interdisciplinary Earth sciences. A primary objective of the facility is improved scientific understanding of the fundamental physics related to interactions between clouds and radiative feedback processes in the atmosphere. ARM focuses on obtaining continuous field measurements and providing data products that promote the advancement of climate models.

Brief History

During the early years of the program, efforts focused on establishment of field research sites, development and procurement of instruments, and development of techniques for both atmospheric retrievals and model evaluation.

To obtain the most useful climate data, three main sites were chosen that represented a broad range of weather conditions. The Southern Great Plains site in Oklahoma provides a wide variability of climate cloud type and surface flux properties, and large seasonal variation in temperature and specific humidity. The North Slope of Alaska site is providing data about cloud and radiative processes at high latitudes, which have been identified as one of the most sensitive regions to climate change. The Tropical Western Pacific locale experiences widespread convective clouds due to the consistently warmest sea surface temperatures on the planet (referred to as the Pacific "warm pool"). Changes in sea surface temperature and convection patterns in this region play a large role in the interannual variability observed in the global climate system.

In addition, the ARM Mobile Facilities contain most of the same instruments as the permanent sites and can support short-term (up to one year) experiments in different climate regions. Airborne measurements from the ARM Aerial Facility have been an integral measurement capability of ARM since 1993 and have used a variety of aerial platforms and instruments during intensive field campaigns or long-term, regularly-scheduled flights.