New Merged Aerosol VAP Now Available

Published: 20 November 2025

Dots indicate particle concentrations over a month for the CCNC (red), CPC fine (blue), and CPC ultra fine (black). The highest concentrations are from the CPC ultra fine. — This figure shows particle concentrations from the Merged Aerosol value-added product for three ARM Southern Great Plains aerosol instruments: the cloud condensation nuclei counter (CCNC), the fine condensation particle counter (CPC), and the ultra-fine CPC. Figure was generated by John Shilling, Pacific Northwest National Laboratory.

The Atmospheric Radiation Measurement (ARM) User Facility has developed and released the new Merged Aerosol value-added product (VAP) to simplify scientists’ use of ARM aerosol data.

The Merged Aerosol VAP consolidates multiple ARM aerosol datastreams into a single file for ARM data users. This VAP streamlines use of ARM data by cleaning up missing data, transforming all measurements onto a common timestamp, and evaluating the best measurements for data users when multiple datastreams exist for a single geophysical quantity. Data are presented on an hourly-averaged timestamp.

Evaluation data from the Merged Aerosol VAP are now available for the following ARM sites:

the Eastern Pacific Cloud Aerosol Precipitation Experiment (EPCAPE) main instrument site on the Ellen Browning Scripps Memorial Pier in La Jolla, California, from February 15, 2023, through February 14, 2024
the TRacking Aerosol Convection interactions ExpeRiment (TRACER) main instrument site in La Porte, Texas, from October 1, 2021, through September 30, 2022
Southern Great Plains extended facility E13 near Lamont, Oklahoma, from November 14, 2016, through June 30, 2025.

Scientists can begin using the Merged Aerosol VAP data now to streamline their aerosol data analyses. In the future, ARM plans to process data for additional sites and field campaigns.

More information about the VAP can be found on the Merged Aerosol web page.

To ask questions, provide feedback, or report data issues before this evaluation VAP moves to production, please contact ARM aerosol translator John Shilling or VAP developer Brian Ermold.

Access the Merged Aerosol VAP data in the ARM Data Center. (To download the data, first create an ARM account.)

Data can be referenced as doi:10.5439/2568164.

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ARM is a DOE Office of Science user facility operated by nine DOE national laboratories.