An official website of the United States government
blue sky with white clouds

World’s premier ground-based observations facility advancing atmospheric research

Power Your Research with ARM

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.

Access ARM Data

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

New to ARM?

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

Use ARM Facilities for Your Research

Explore the ARM Observatories

Read the Latest from ARM

An uncrewed aerial system flies over a forest with buildings and roads visible in the middle of clearings. Patches of brown and green are seen throughout the forest.

Features

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.

Welcome to the New-Look ARM.gov!

27 February 2025

ARM.gov has gotten a refresh after more than eight years with its previous look. Peruse the site's new features!

Busy at Bankhead

27 February 2025

More instruments are going up at ARM’s newest long-term atmospheric observatory, and science activity is increasing.

A time-series plot showing aerosol absorption coefficient at three wavelengths: 464, 529, and 648 nanometers

Data Announcements

Aerosol Optical Properties Data Produced for 2 Ongoing ARM Deployments

31 July 2025

The Aerosol Optical Properties (AOP) value-added product is now available for ARM’s Bankhead National Forest atmospheric observatory in Alabama and the Coast-Urban-Rural Atmospheric Gradient Experiment (CoURAGE) in the Baltimore, Maryland, area.

New ARM Trajectory Data Now Available for Evaluation

18 July 2025

The multipurpose ARM trajectory (ARMTRAJ) value-added product now consists of six trajectory data sets to support atmospheric research using ARM data.

New Cloud Optical Properties Data Released

16 July 2025

This value-added product generates cloud optical depth for overcast liquid clouds using ARM multifilter rotating shadowband radiometer measurements.

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

Research Highlights

Seasonality and albedo dependence of cloud radiative forcing in the upper Colorado River basin

3 July 2025

The hydrologic cycle is strongly influenced by the balance of sunlight and thermal radiation on the ground or snow surface. We quantify the combined impacts of clouds and snow cover on the surface radiative energy balance in a high-elevation region of the upper Colorado River basin. Since snow is bright and reflects sunlight, our results demonstrate that the surface energy balance will become increasingly sensitive to cloud cover as snow cover declines. 

New parameterizations to connect aerosol phase state with their ice nucleation abilities

27 June 2025

We combined laboratory experiments, modeling, and field data to demonstrate that organic aerosols may significantly contribute to the formation of ice clouds in certain atmospheric regions.

AI-based classification of marine cloud cell patterns from ARM radar

1 May 2025

Marine stratocumulus clouds often organize into mesoscale cellular convection (MCC), forming large-scale open or closed cell patterns. However, Earth system models struggle to simulate these regimes due to limited observations and understanding of physical processes. In this study, researchers at Pacific Northwest National Laboratory applied an artificial intelligence/machine learning (AI/ML) approach to analyze long-term vertically pointing cloud radar data from the Atmospheric Radiation Measurement (ARM) user facility’s Eastern North Atlantic (ENA) site. The method enables continuous time series of MCC classification, performs well, and reveals clear cloud and meteorological differences between the two MCC types. It also holds great potential for application to other ARM locations.

ARM Logo

Follow Us:

Keep up with the Atmospheric Observer

Updates on ARM news, events, and opportunities delivered to your inbox

Subscribe Now

ARM User Profile

ARM welcomes users from all institutions and nations. A free ARM user account is needed to access ARM data.

Atmospheric Radiation Measurement (ARM) | Reviewed March 2025