ARL, a present-day OAR lab and former ESSA Research Laboratory, develops and improves atmospheric dispersion and air chemistry models; collects research-grade atmospheric and deposition measurements of select air chemistry parameters; studies the atmospheric boundary layer by collecting and analyzing essential data of surface and near surface weather and climate conditions; and provides high quality, reference-grade measurements of critical climate parameters. ARL includes four research divisions: the Atmospheric Sciences Modeling Division (ASMD), the Atmospheric Turbulence and Diffusion Division (ATDD), the Field Research Division (FRD), and the Special Operations & Research Division (SORD).
The former Atmospheric Turbulence and Diffusion Laboratory has now been absorbed into ARL as a division. However, this organization traces its roots to a Weather Bureau Research Station established in 1948 as part of the larger US government nuclear efforts in Oak Ridge TN, in order to provide insight into the movement of radionuclides dispersed in the atmosphere. During the ESSA era, research revolved around climatological data gathering and analysis, planetary boundary layer studies, plume dispersion studies, turbulence and diffusion in the lower atmosphere, ecology-meteorology interaction, and a Nuclear Safety Information Center.