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 DOE Office of Science user facility, ARM makes its data freely available to scientists around the world.

Use ARM Facilities for Your Research

ARM instruments and containers line the edge of grass and gravel path. The sky is orange and cloudy. Street lights are seen in the distance.
Featured Field Campaign

Coast-Urban-Rural Atmospheric Gradient Experiment

1 December 2024 - 30 November 2025 View All Campaigns

Explore the ARM Observatories

Read the Latest from ARM

A person leans over to look at the adjustment they are making to a set of radiometers.

Features

Brave New CoURAGE Campaign Set to Begin

2 December 2024

In and around Baltimore, Maryland, scientists, technicians, and students are poised for a year of measuring an urban atmosphere during the Coast-Urban-Rural Atmospheric Gradient Experiment (CoURAGE).

5 Years Later, Updates From 4 DOE Early Career Awardees

26 November 2024

Scientists share their accomplishments with ARM data during their five-year U.S. Department of Energy Early Career Research Program projects.

An Epic Arctic Expedition Turns 5

25 October 2024

Papers pour in from the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, revealing new findings about the data-sparse and vulnerable region.

The x-axis of the plot is labeled Time in UTC (HH) from 0 to 24 and the y-axis Height (m) from 0 to 4,000. The legend shows 1 to more than 1,000 N(ccn)/cc.

Data Announcements

Cloud Condensation Nuclei Vertical Profile Data Product Extended to ENA

15 January 2025

The Retrieved Number concentration of Cloud Condensation Nuclei (RNCCN) value-added product is now available for evaluation for the Eastern North Atlantic (ENA) atmospheric observatory.

Users Ask for New Arctic Aerosol Measurements, and ARM Listens

26 November 2024

ARM has installed a set of three instruments at a NOAA site in Utqiaġvik (formerly Barrow), Alaska, to help give scientists a richer picture of atmospheric particles in the Arctic.

New Merged Product Integrates G-1 Flight Data

26 November 2024

This product, currently available for three ARM field campaigns, allows users to quickly access key measurements from nearly two dozen ARM Aerial Facility products.

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

Research Highlights

Increasing model spatial resolution fails to reduce simulated storm biases

21 January 2025

Accurately predicting impacts from storms depends on accurately simulating their growth as a function of atmospheric conditions. Using a model setup like those used for operational forecasting, results show that total storm rainfall over a large area is reasonably predicted. However, heavy rain rates were too frequent and light rain rates were too infrequent at a local scale when compared to observations, meaning the balance between rainfall frequency and intensity is incorrectly predicted. This is caused by an excessive number of simulated storms, a model bias that worsens as the atmosphere becomes more stable. Increasing model resolution to better resolve storm circulations does not reduce these biases, indicating model representation of precipitation formation and growth in storms requires improvement.

New methods for extracting more detail from existing data sets

21 January 2025

Detailed data of what is in the atmosphere is often very complex, containing thousands of chemicals without known identities or properties. By developing new automated tools for analyzing certain types of data, this research will substantially improve the ability to make sense of these data and extract new details about the composition of the atmosphere.

Bridging the data gap in Southern Hemisphere aerosol research

17 January 2025

Aerosols are known to affect cloud properties, including their formation, growth, and precipitation, which in turn influences climate over long time scales. Aerosol-cloud-interactions (ACI) depend on how their properties change together, yet few measurements capture this variability, especially in the presence of convective cloud populations that can be observed routinely by satellites. Models are often challenged because they assume aerosols are constant, which potentially leads to erroneous estimates of the impact of ACI. Furthermore, ACI pathways in convective clouds are complex and remain highly uncertain.   To address the data gap and better understand the interactions of convective clouds and the surrounding environment, extensive in situ and remote-sensing measurements were collected during the Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign conducted between October 2018 and April 2019 over the Sierras de Córdoba range of central Argentina. The field campaign aimed to understand how convective clouds interact with environmental conditions, thermodynamics, aerosols, and surface properties. In contrast with previous studies that focused on clouds, this study describes measurements of aerosol number, size, composition, mixing state, and cloud condensation nuclei collected during CACTI.

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 October 2024