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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

Portrait of Alfonso Ladino-Rincon

Features

PhD Student Helps Bring Py-ART, Open Radar Data to the Masses

17 March 2026

Alfonso Ladino-Rincon, who attended ARM's 2024 summer school, works on projects to support the growth of the open science community.

Charting a Bold Course for AI Integration

12 March 2026

A new phased approach for artificial intelligence (AI) prioritizes transparent governance, AI‑ready infrastructure, and user engagement to accelerate discovery across the ARM community.

Researchers Apply ARM Data to Refine Aerosol-Cloud Interaction Simulations

18 February 2026

A recent paper uses observations from ARM and other field campaigns to evaluate simulations from the U.S. Department of Energy's Energy Exascale Earth System Model at kilometer-scale resolution.

Lines show pressure and temperature recorded by an ARM radiosonde. Two dots on the plot indicate different radiosonde parameters.

Data Announcements

Radiosonde Parameters Product Released for CoURAGE, EPCAPE Campaigns

11 May 2026

The Convective Parameters Derived from Radiosonde Data (SONDEPARAM) value-added product applies stable and consistent algorithms to ARM radiosonde data to calculate useful convective cloud parameters.

ARM Produces First Characterized and Corrected NSA XSAPR Data

14 April 2026

The X-Band Scanning ARM Precipitation Radar (XSAPR) at ARM’s North Slope of Alaska (NSA) atmospheric observatory provides valuable dual-polarization measurements of arctic precipitation.

Characterized, Calibrated Fixed-Site KAZR Data Available for 2025

10 April 2026

These newly released data from the Ka-Band ARM Zenith Radar (KAZR) have undergone calibration, correction, and quality control processes beyond ARM’s standard quality checks and corrections.

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

Research Highlights

Aerosol Influences on Cloud Water: Insights from EPCAPE Data with Explainable Machine Learning

11 April 2026

Aerosol-cloud interactions remain one of the largest uncertainties in physical process understanding and long-term projections. A key challenge is disentangling causality in observed aerosol-cloud relationships, as both variables can be independently influenced by large-scale meteorology. To address this, we apply an explainable machine learning (ML) framework to isolate and examine the individual effects of aerosols and meteorological factors (MFs) on cloud liquid water path (LWP), using recent observations from the Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) field campaign conducted by the Atmospheric Radiation Measurement (ARM) User Facility.

Optimizing Cloud Droplet Sampling with Pumped Counterflow Virtual Impactors

23 March 2026

Atmospheric particles act as nuclei for the formation of cloud droplets. To study these nucleation processes, pumped counterflow virtual impactors are often used because they can separate cloud droplets or ice crystals from inactivated particles. In this study, we compared the performances of three commercial units in a laboratory setting using dry aerosols and cloud droplets. We quantified how the transmission efficiency varies with flow rates and particle types, and identified the operating conditions that optimize the collection of activated particles.

New Insights into Aerosol-cloud Interaction Over the Eastern North Atlantic

16 March 2026

While a non-monotonic (“inverted-V”) cloud response to aerosol perturbation—initial cloud thickening via precipitation suppression followed by enhanced evaporative dissipation—has been previously reported, its meteorological conditioning remains unresolved. Using a deep-learning framework to objectively classify Eastern North Atlantic synoptic regimes, we show that the cloud response is strongly regime-dependent and that the U.S. Department of Energy's earth system model (E3SMv2) systematically overestimates liquid water loss, particularly in dynamically complex, precipitating environments with strong vertical motion. These biases are linked to uncertainties in models representing drizzle, entrainment, and turbulent processes.

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Atmospheric Radiation Measurement (ARM) | Reviewed March 2025