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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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Read the Latest from ARM

Dark clouds sit over containers and atmospheric instrumentation, including a pair of aerosol sampling stacks, with shrubs, palm trees, and a modern academic building nearby.

Features

ARM Conducts Phoenix Study to Unlock Secrets of Monsoon Storms

30 July 2026

A field campaign hosted by Arizona State University will explore how extreme heat, urban growth, and dust influence storm intensity.

Longtime ARM Director Winds Down Impactful Career

20 July 2026

Jim Mather, who is retiring this summer after three decades with ARM, reflects on his life and career.

ARM Names New Director

13 July 2026

Atmospheric scientist Larry Berg will guide ARM into the next era of scientific observations and succeed Jim Mather, who has led ARM since 2007.

A grid of eight maps shows daily geopotential heights (meters, contours) and anomalies (colors) at 500 hPa at 05:00 UTC for eight self-organizing map nodes. Nodes 0, 1, 4, and 5 are ridge regime; nodes 2 and 7 are pre-trough regime; and nodes 3 and 6 are post-trough regime. Maps are provided by Aifang Zhou, Brookhaven National Laboratory.

Data Announcements

ARM Fills In 2024–2025 BNF Synoptic Weather Regime Classification Data

3 September 2026

A full seasonal cycle of data from the Synoptic Weather Regime Classification (SynopWeaReg) machine learning value-added product is now available for ARM’s Bankhead National Forest (BNF) atmospheric observatory in Alabama.

Additional Enhanced Cloud Microphysics Data Released to Production

11 August 2026

Along with releasing new production data from its Improved Continuous Baseline Microphysical Retrieval (MICROBASE) product with uncertainty estimation, ARM has reprocessed previously released versions of MICROBASE products and renamed them as MICROBASE.

New Microwave Radiometer Retrieval Data Released

3 August 2026

The Microwave Radiometer Retrievals (MWRRET) value-added product is available for the first time for several ARM sites. In addition, the MWRRET data set for ARM’s North Slope of Alaska atmospheric observatory has been extended.

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

Research Highlights

Deviations From Mixed-Layer Similarity in the Moist Convective Boundary Layer

27 July 2026

We systematically investigated the influence of water vapor fluctuations on turbulence statistics in the convective atmospheric boundary-layer using a series of numerical simulations. Although water vapor is typically assumed to play a passive role in turbulence dynamics, we find that it plays an active role, where it contributes to buoyancy independently of temperature and influences the nature of turbulent transport under humid conditions.

Aircraft Flux Measurements Pinpoint Where New Particles Form in the Marine Boundary Layer

27 July 2026

New aerosol particle formations within the marine boundary layer (MBL) have been difficult to pin down, limiting how well earth system models represent this aerosol source. Using measurements from the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) Aerial Facility's G-1 aircraft during the Aerosol and Cloud Experiments in the Eastern North Atlantic (ACE-ENA) campaign, researchers applied a continuous wavelet transformation technique to derive vertical turbulent fluxes of freshly nucleated 3-10nm particles. This approach sidesteps the stationarity assumptions that limit traditional eddy covariance methods on a fast-moving aircraft platform, and it uses flux direction—upward versus downward—to infer whether a nucleation source lies above or below the aircraft.

Detectable Ship Tracks Account for Just 5% of Aerosol Indirect Forcing from Ship Emissions

21 July 2026

95% of the impact on clouds by aerosols emitted by ships is realized through invisible routes instead of explicitly visible ship tracks. This highlights the importance of detecting and attributing aerosol effects on clouds.

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Atmospheric Radiation Measurement (ARM) | Reviewed March 2025