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The U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) User Facility provides 30-plus years of atmospheric measurements, including data sets from all seven continents and five oceans, to advance the understanding of the Earth’s atmosphere.

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ARM collects continuous measurements and develops data products that promote the advancement of earth system models.

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As a U.S. Department of Energy Office of Science user facility, ARM makes its data freely available to scientists around the world.

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Read the Latest from ARM

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Features

Bankhead National Forest After 1 Year: From Vision to Reality

24 November 2025

Learn how ARM’s newest atmospheric observatory grew in capabilities, scope, and data during its first year of operations in northern Alabama.

Remembering Ken Kehoe of the ARM Data Quality Office

26 September 2025

Kehoe, the associate manager of the ARM Data Quality Office, passed away August 13, 2025, at age 48.

Bankhead National Forest Observations Are Reaching Full Speed

17 July 2025

Continuous data and measurements from recent intensive operations, including ArcticShark uncrewed aerial system flights, are available from ARM’s atmospheric observatory in Alabama.

A crop of a time-series plot generated using the PrecipBE Jupyter Notebook shows precipitation rate during a period of the CACTI campaign in Argentina. Image is by Israel Silber, Pacific Northwest National Laboratory.

Data Announcements

New Precipitation Best Estimate Data Released for Evaluation

30 December 2025

The Precipitation Best Estimate (PrecipBE) product provides time-series data and statistics on precipitation events measured at ground level by ARM.

Tethered Balloon System Merged Data Produced for BNF and CoURAGE Flights

30 December 2025

This value-added product allows for examination of cloud-base and boundary-layer heights while making it easier to access and use measurements from ARM tethered balloon system missions.

ARM Improves Merged Aerosol Size Distribution Machine Learning Product

11 December 2025

New data are now available for the 2023–2024 Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) from this updated product.

Clouds roll across the sky over the Kennaook/Cape Grim area.

Research Highlights

Climatology of Cloud-Land-Surface Coupling Across Different ARM Sites

7 January 2026

Land-atmosphere interactions are crucial for the formation and evolution of low-level clouds and planetary boundary layer (PBL). However, characterizing the different coupling states between clouds and the surface is uncertain, particularly in continental regions due to complex thermodynamics. This study examines cloud-surface coupling at five ARM sites across three continents, highlighting both the complexities and commonality of cloud-land-surface interactions.

Systematic Cloud Microphysics Scheme Development with Machine Learning

6 January 2026

Cloud microphysics refers to the microscale processes that impact liquid droplets and ice crystals in clouds and precipitation. Because of uncertainty in both cloud microphysical processes and in how these processes should be represented in models, they are a major source of uncertainty in current weather and climate models. The recent application of machine learning (ML) methods to atmospheric model development holds significant promise to address current limitations in modeling cloud microphysics and thus improve atmospheric models. In this perspectives paper, we discuss both challenges and future opportunities in applying ML methods to cloud microphysics.

Investigating the Dynamics of Thunderstorm Downdrafts

6 January 2026

Downdrafts, or downward moving currents of air, form around the edges of thunderstorms. They can be an important feature of severe thunderstorms, particularly downbursts, and can be hazardous to aviation as well as drive strong surface winds. More generally, downdrafts are also important for the vertical transport of energy, dry air, and aerosols and chemical constituents in the atmosphere. However, uncertainty about the mechanisms driving downdrafts remains, and this study uses numerical modeling to address this knowledge gap.

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Atmospheric Radiation Measurement (ARM) | Reviewed March 2025