Bankhead National Forest

The Bankhead National Forest (BNF) atmospheric observatory is a long-term mobile observatory being established by the Atmospheric Radiation Measurement (ARM) user facility in northwestern Alabama. The BNF is currently expected to be operational for five years, starting in 2024.

Scientists will use data from the BNF to learn about clouds, aerosols, and land-atmosphere interactions, which in turn will lead to improvements in earth system models.

An ARM Mobile Facility workshop in August 2018 identified the Southeast as a priority region of interest for further study by ARM. The Southeast is a region with abundant atmospheric convection, yet the land surface, boundary layer, vegetation, and aerosol properties are markedly different from those seen at ARM’s Southern Great Plains fixed observatory in Oklahoma, allowing for opportunities to explore new research questions.

The U.S. Department of Energy selected a multi-institutional site science team, led by Brookhaven National Laboratory in New York, to develop the science plan and initial research project for the BNF observatory. This team, supported by ARM and Atmospheric System Research (ASR), provided scientific guidance to ARM on the BNF’s location and measurement strategy.

With the new observatory, the BNF site science team plans to improve process understanding and model representations of aerosols, clouds, and land-atmosphere interactions, together with key cross-coupling of those areas to explore land-atmosphere feedbacks and aerosol-cloud interactions.

In addition, the BNF site science team envisions the observatory as a testbed for scientists to apply artificial intelligence and machine learning techniques and capabilities to advance earth system predictability.

The BNF is being installed in a phased approach with the main site and three supplemental sites operational first. Tower and scanning radar sites will be operational at later dates. ARM is currently accepting letters of intent and preliminary proposals for uncrewed aerial system (UAS) flights in the BNF area in June and/or August 2025.

Instrument platforms and suites at the BNF’s main site include:

• radiometers
• radars
• lidars
• surface meteorological instrumentation
• aerosol instrumentation
• an all sky imager
• a ceilometer
• radiosondes.

Near the main site, a 140-foot (42.7-meter) instrumented tower will sample a variety of parameters below, within, and above the forest canopy.

The supplemental sites are equipped with a subset of instruments to provide parameters outside of the forest, including thermodynamic profiles, surface fluxes, and aerosol properties. ARM will have two scanning radar sites for observing clouds and precipitation over the region.

ARM will transmit all data gathered at the BNF to the ARM Data Center, and they will be made freely available to the scientific community via Data Discovery.

Researchers will be able to supplement the continuous ARM observations with guest instruments during field research campaigns or by requesting increases in the frequency of measurements, such as sonde launches. Guest instrument deployments require an ARM field campaign proposal. Because the Bankhead National Forest is managed by the U.S. Forest Service, guest instrument activities may need additional approval. ARM encourages scientists to plan ahead and submit requests early for any potential guest instrument activities.