Boon of New Aerosol and Trace Gas Data for ARM Users

Published: 16 February 2021
Aerosol Observing System at ARM's Southern Great Plains atmospheric observatory
Aerosol Observing Systems, such as this one at the Southern Great Plains atmospheric observatory, are ARM’s primary platforms for in situ aerosol measurements at Earth’s surface. Photo is courtesy of Janek Uin, Brookhaven National Laboratory.

The Atmospheric Radiation Measurement (ARM) user facility recently released b1-level data products for aerosol size distributions, aerosol chemical composition, and trace gases to the ARM Data Center.

ARM b1-level products undergo calibration, correction, and quality control processes beyond the facility’s standard quality checks and corrections. Oftentimes, b1-level products are then further developed into c1-level value-added products.

The recent aerosol and trace gas b1-level releases are part of ARM efforts to harmonize—or standardize—data from instruments within its Aerosol Observing Systems (AOS).

Across ARM, b1-level data are now available for the ultra-high-sensitivity aerosol spectrometer (UHSAS), aerodynamic particle sizer (APS), and regular and nanoparticle scanning mobility particle sizers (SMPS and nanoSMPS). The b1 processing converts raw (a1-level) counts from these four instruments to the same units and standardizes variable names.

Data are now available in the ARM Data Center for the following sites and field campaigns:

In a future development, some of these data will be merged into a single, consistent size distribution that covers the entire measured size range.

ARM also has new b1-level chemical composition data from the quadrupole aerosol chemical speciation monitors (ACSMs) at the ENA and SGP E13. The new AOSACSM data, from September 2019 onward, are available in near-real time in the ARM Data Center.

The b1 ACSM processing gives users calibrated concentrations of organics, sulfate, nitrate, ammonium, and chloride; quality assurance/control; and a volume concentration to facilitate comparison to size distribution measurements.

For trace gases, recent b1-level releases include calibrated AOS ozone monitor (AOSO3) data from the ENA, SGP E13, AMF3, COMBLE, and MOSAiC. These data are available now in the ARM Data Center.

The b1 processing routine applies the appropriate calibration to the data, evaluates the instrument baseline by analyzing the automated zero measurements, and subtracts it from the data.

To download data from the ARM Data Center, you must have an ARM account. Create an ARM account now.

If you have questions or feedback about the data, please contact ARM translator John Shilling.

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