This year marks the 75th anniversary of NOAA’s Air Resources Laboratory, located in College Park, Maryland with field stations in Tennessee, Idaho and Nevada. Here are six facts about the lab.
ARL is one of NOAA’s oldest labs, was a product of the Cold War.
ARL’s research focus is on the boundary layer, the part of the atmosphere from a few feet below the soil up to 2-3 miles above the Earth. ARL scientists study the physical and chemical processes that occur in the boundary layer, on time scales spanning a few hours to several years.
Originally established in 1949 by the U.S. Weather Bureau, predecessor of NOAA’s National Weather Service, ARL’s original main mission was to study atmospheric dispersion and conduct meteorological surveys. The idea was to provide detailed information regarding wind flow patterns and other factors to determine how radioactive contaminants might move through the boundary layer.
In the decades that followed, the lab expanded its mission to include air pollution, the development of models that forecast trajectory and dispersion and demonstrate effectiveness of new air quality regulations, such as the Clean Air Act, and the development of a wildfire smoke forecast system. ARL researchers also contributed to the first four Assessment Reports on Climate Change for the Intergovernmental Panel on Climate Change in the 1990s and early 2000s. In the following years the lab worked on several large national disasters including the Deepwater Horizon Oil Spill (2010) and the Mauna Loa, Hawaii volcano eruption in 2022.
ARL provided critical tracking after the Chernobyl and Fukushima Nuclear Accidents
In addition to work on domestic events, ARL has been a part of several international post-disaster research efforts. The lab has put its expertise to work following two high profile nuclear disasters.
In 1986, ARL researchers unveiled where the Chernobyl accident happened. ARL Director at the time, Lester Machta, got a call about very high radiation readings in Sweden on Monday, April 28 wanting ARL to look into it. The main concern at that moment was securing the safety of U.S. troops stationed all over Europe. ARL Director Machta asked staff scientists to do some back trajectories from where the sample was taken. This involves tracing backwards from where the sample was taken to find the source. They originally thought the radiation might be coming from one of the many power plants in France, where there were a lot of U.S. troops. But, when scientists did the back trajectory, the trail led to present day Ukraine which was part of the Soviet Union. The government immediately got on the phone with the Soviet embassy and the Soviets finally admitted that there was a “small accident” at Chernobyl the Saturday before. The Soviet Union had not told anyone about the disaster until ARL was able to point very close to where the radiation had originated.
And in 2011, ARL employed its HYSPLIT model to evaluate the meteorological transport and dispersion aspects of the Fukushima Daiichi nuclear power plant accident. ARL experts were also able to provide information that could be used to improve the detection of nuclear accidents in the future.
ARL developed a volcanic ash model essential to the Volcanic Ash Advisory Centers
In 1997, the International Civil Aviation Organization designated a network of Volcanic Ash Advisory Centers, two of which NOAA operates, established to track volcanic plumes and ash to warn the aviation industry of hazardous conditions. ARL researchers developed the HYSPLIT volcanic ash model specifically for this purpose. Developed in the early 2000s, HYSPLIT has since become the backbone of the Volcanic Ash Advisory Centers dispersion modeling.
ARL’s involvement in this area dates back to the 1980 Mount St. Helens eruption where the lab created text only trajectory forecasts. By the 1989-1990 Mount Redoubt eruptions in Alaska, ARL had developed volcanic ash forecast guidance to support safe flight and had created the Volcanic Ash Forecast Transport and Dispersion Model. This early model basically just gave a qualitative “ash” or “no ash” output.
ARL has maintained a network of accurate U.S. climate data for over 20 years
The U.S. Climate Reference Network has been a part of ARL since it became operational in 2002. ARL and the NOAA’s National Centers for Environmental Information developed this network of high quality, reference-grade measurements necessary to document climate change trends. ARL manages, operates and maintains 141 stations across the continental U.S., Hawaii and Alaska. NCEI manages, maintains and provides public access to the data from the network.
A team of eight technicians and engineers are responsible for annual maintenance visits to each tower. These sites are deliberately located away from urban and suburban areas to avoid local biases in the climate record and some of them are very remote. ARL is very strict about maintaining the integrity of the towers and the measurements as they are used to analyze long-term datasets to understand climate variability and change and to evaluate other observing networks. Observations are also used in the decision support activities for weather warnings, water resource management, and to improve both short and long term forecasts to protect lives and property.
ARL helps emergency managers keep their communities safe
Following 9/11, dispersion scientists within ARL realized the critical need for forecasting dispersion of chemicals, debris or radiation in urban areas and cities. In effect, city managers didn’t have reliable guidance on how to protect people after an event where chemicals, debris or radiation were released into the air. As a result, ARL developed DCNet – the precursor to today’s UrbanNet – to develop a methodology that would help predict dispersion using city-specific wind flow.
Today’s UrbanNet project uses sensors that provide continuous high-resolution meteorological measurements on five sites in the DC metro region that allow for much more accurate modeling. In addition, this project is supporting climate and greenhouse gas monitoring in urban areas, where the global population is increasingly living and working. UrbanNet observations will play a key role in evaluating and improving emissions inventories, providing federal and state regulatory agencies with policy-relevant science information they can use to guide mitigation efforts and implement strategies to control air pollution.
ARL created an opportunity to collaborate with minority-serving institutions
In honor of ARL’s 75th Anniversary, the Scientist-in-Residence program was created in 2024 in collaboration with the NOAA Office of Education. The goal of this program is to advance scientific understanding of the processes in the boundary layer on local, regional and global scales and to promote collaboration with minority-serving NOAA Cooperative Science Centers. Early and mid-career faculty at those science centers can apply for a two-month residency collaborating with ARL scientists.
ARL Director Ariel Stein said: “We created this opportunity to engage and strengthen research collaborations with faculty at minority-serving institutions. These connections serve to increase understanding of NOAA’s work and leverage expertise of early and mid-career faculty and their students focusing on atmospheric boundary-layer research.”
This year’s inaugural recipient was Osinachi Ajoku, an assistant professor of Atmospheric Science at Howard University and the NOAA Center for Atmospheric Sciences and Meteorology. He is investigating the impacts of regional emissions and long-range transport of ozone and aerosols on boundary layer evolution with ARL’s Mark Cohen who is an expert in this area.
*An earlier version of this story incorrectly stated that ARL had maintained a climate data network for 30 years. The text was changed to reflect that the Climate Reference Network became operational in 2002.
Media contact: Alison Gillespie, 202-713-6644, alison.gillespie@noaa.gov
