About ARM
The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE). 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. A primary objective of the program 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 measurement 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/Adjacent Arctic Ocean 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 plays a large role in the interannual variability observed in the global climate system, due to the consistently warmest sea surface temperatures on the planet (referred to as the Pacific "warm pool"). In addition, a Mobile Facility completed in 2004 contains most of the same instruments as the permanent sites. Because of its portability and flexibility, the Mobile Facility can support short-term (up to one year) experiments in different climate regions.
Instrument development and procurement were pursued with a fundamentally new idea in mind: carry out continuous and simultaneous ground-based observations of the atmospheric column using a suite of passive and active sensors. Previously, most sensors used to investigate atmospheric properties and compositions were strictly research instruments and, in many cases, inadequately understood and calibrated. ARM's new generation of ground-based remote sensing instruments include millimeter cloud radar, Raman lidar, infrared interferometers using electronic coolers rather than cryogens, and updated sky imagers, among others.
Because side-by-side comparisons and calibration techniques are critical to instrument understanding, ARM sponsored and hosted at its field sites a number of campaigns focused on this subject. ARM also funded the development of a broad range of retrieval techniques using single and multiple streams. Key advances were made in the areas of radiation and aerosol parameterizations, cloud properties algorithms, and cloud modeling/parameterizations versus observations and data analysis.
Up and Running
With the successful completion of these initial efforts, ARM scientists have the access and tools necessary to conduct their research with program partners across the globe. Instrumented field sites operate continuously, providing data that are reviewed for quality then stored in the ARM data archive for use by the atmospheric science community. By publishing their research results in peer-reviewed journals, ARM-sponsored investigators are contributing important findings related to the field of climate science, particularly in the areas of atmospheric radiation and cloud research. In addition, ARM's field research sites and data archive can serve as scientific user facilities for collaborative research primarily with university, government agency, and national laboratory researchers.
