Guidelines : Tethered Balloon System Missions

In fiscal year 2026 (FY2026), the Atmospheric Radiation Measurement (ARM) user facility plans to conduct approximately six to eight tethered balloon system (TBS) missions using ARM TBS baseline instruments, with missions taking place over two-week periods. Missions are being planned to take place at ARM’s Southern Great Plains (SGP) atmospheric observatory in Oklahoma and the Bankhead National Forest (BNF) observatory in Alabama. ARM is also exploring the possibility of TBS missions for the upcoming 2026 deployment in Phoenix, Arizona.

Two ARM TBS calls are now open for FY2026. ARM is accepting preliminary proposals for TBS missions while also participating in a joint TBS call with the Environmental Molecular Sciences Laboratory (EMSL). Like ARM, EMSL is a U.S. Department of Energy Office of Science user facility.

Awarded projects from the ARM/EMSL and ARM-only calls will begin no earlier than Wednesday, October 1, 2025.

ARM and EMSL are seeking collaborative research applications through the Facilities Integrating Collaborations for User Science (FICUS) program, which encourages and enables ambitious research projects integrating the expertise and capabilities of multiple user facilities.

Through the new FICUS call, researchers can apply to use EMSL instruments to collect samples of aerosols and volatile organic compounds on ARM TBS flights and then conduct analysis using advanced laboratory techniques at EMSL. For information about the EMSL instruments available for this call, read the ARM/EMSL FICUS FY2026 solicitation.

Proposed research should investigate aerosol processes, aerosol-cloud interactions, or land-atmosphere processes over rural, urban, and coastal areas toward improved earth system models and mechanistic representations of these processes.

FICUS applicants may propose to analyze samples from past TBS missions or from planned FY2025 missions at the BNF or as part of ARM’s Coast-Urban-Rural Atmospheric Gradient Experiment (CoURAGE) in Baltimore, Maryland.

In addition, applicants may propose new FY2026 missions for the BNF or SGP sites. Mission proposals will also be considered for ARM’s Desert-Urban SysTem IntegratEd AtmospherIc Monsoon (DUSTIEAIM) field campaign in Phoenix for the period of April through September 2026.

Proposals requesting the EMSL instruments and sample analysis must be submitted to the ARM/EMSL FICUS FY2026 solicitation.

FICUS submissions will require a letter of intent to facilitate the planning of the peer-review process, ensure alignment of proposals to ARM and EMSL missions and capabilities, and assist users in building strong proposals. More information about letter-of-intent requirements is available on this FICUS guidance web page.

Letters of intent are due Tuesday, February 4, 2025. FICUS decisions and invitations for full proposals will be sent by Tuesday, March 4, 2025.

The ARM-only call is for projects that do not require EMSL instruments and sample analysis. Applicants may propose FY2026 TBS missions for the SGP or BNF sites, or for the DUSTIEAIM deployment in Phoenix.

In their preproposals, investigators should provide information on mission expectations as listed in the next section. Preproposals must be submitted through ARM’s Propose a Field Campaign page.

The due date to submit preproposals for FY2026 ARM TBS missions is Tuesday, February 4, 2025. Decisions and invitations for full proposals will be sent by the end of February 2025.

Investigators proposing for either call are asked to propose no more than three missions, and requests for multiple missions should be well justified.

For each mission, 14 flight days are expected. (Note: Because BNF flights are only anticipated to be permitted from Wednesday night to Monday morning, ARM expects BNF flight missions to take place over three weeks.)

The balloon must remain in clear air and below the base of nearby clouds. TBS flights are generally restricted to a maximum altitude limit of 1.5 kilometers above ground level, and an individual flight typically lasts from a few hours to approximately eight hours with varying flight styles.

Please be aware that all TBS missions are contingent upon approval from the Federal Aviation Administration (FAA). ARM is seeking permission from the FAA for FY2026 operations at the SGP and BNF sites and for the DUSTIEAIM campaign and will revisit the feasibility of operations at these locations at the full proposal stage. Daytime and nighttime operations may be proposed for the SGP, BNF, and DUSTIEAIM.

Proposals for new TBS missions in FY2026 should provide details regarding mission expectations, including:

• needed instrumentation
• the flight location (SGP, BNF, or DUSTIEAIM)
• desired season or seasons
• desired time of day
• desired altitude
• the number and duration of flights required
• desired meteorological conditions during the flight
• whether fixed-altitude flights or profiles would be more appropriate for the applicant’s science goals, and where these factors are important for achieving their science goals.

Proposals for flights of non-baseline ARM instruments or guest instruments (including those listed on the TBS baseline instrument web page) will also be considered but will need to be reviewed in consideration of payload constraints.

For people interested in participating in either call and/or using TBS data in their research, ARM hosted a TBS webinar in January 2024. The webinar included information about ARM’s TBS capabilities and data. Watch the webinar recording now.