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

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

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

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

William Gustafson, who leads the Large-Eddy Simulation (LES) ARM Symbiotic Simulation and Observation (LASSO) activity, shares how you can access what is now available for the new Eastern North Atlantic (ENA) shallow marine cloud scenario.

Production data are now available from the Improved Continuous Baseline Microphysical Retrieval (MICROBASE) product with uncertainty estimation, previously known as MICROBASEKAPLUS.

Aerosols influence how clouds form, persist, and reflect sunlight, but their interactions remain one of the largest uncertainties in earth system modeling. Researchers used a regional testbed of the Energy Exascale Earth System Model (E3SM) with regionally refined meshes (RRMs) to explore how kilometer-scale resolution changes the simulation of aerosols and clouds across diverse regions—from the Central United States to the Southern Ocean. Simulations were evaluated against observational data from Atmospheric Radiation Measurement (ARM) User Facility, satellite, and other field campaign and surface measurements. The field campaigns (HI-SCALE, ACE-ENA, CSET, and SOCRATES) supply in situ aerosol and cloud microphysical properties, while satellite and surface observations provide additional constraints on cloud cover, cloud condensate amount, and precipitation. Convection-permitting RRM improves heavy-rain representation but worsens light-drizzle biases in marine regimes; cloud cover and liquid water path (LWP) agree better with geostationary satellite retrievals, while some surface comparisons favor the coarse-resolution model. For aerosols, kilometer-scale simulations exhibit higher ultrafine aerosol number concentration due to stronger new particle formation (NPF) while reducing accumulation-mode aerosol numbers through more efficient precipitation scavenging over oceans. Increasing resolution also enhances deposition and coagulation in some continental boundary layers. These shifts cut cloud condensation nuclei (CCN) and drive large reductions in cloud-droplet number (Nd), with broader implications for albedo and lifetime effects. Notably, several ACI process relationships improve: the CCN–Nd correlation moderates toward observations, and LWP–Nd behavior is better captured, indicating gains in the realism of ACI coupling even as absolute biases persist. These results reveal how model resolution modifies the processes linking aerosols to clouds and highlight where physical representations must be refined.

This paper describes development of a data set for 10 different U.S. Department of Energy Atmospheric Radiation Measurement (ARM) User Facility sites that harmonize aerosol measurements from multiple collocated instruments. The data set includes aerosol microphysical, chemical and optical properties at hourly and (where possible) 5min resolution.

Collaborative capabilities were designed to enable unique measurements of aerosol optical properties, water uptake, cloud formation potential, and chemical composition to understand how sources, aging and mixing affect energy within earth systems. Three aerosol regimes were probed in depth during a summer campaign in Houston, Texas: urban, particle growth, and dust.