Aerosol Optical Depth Best Estimate Data in Production for NSA

Published: 26 February 2025

Time series show the combined aerosol optical depths (AODs) generated for the North Slope of Alaska central facility at Utqiaġvik (top panel) and the Atqasuk site (bottom panel). For both sites, aerosol optical depths are provided at 415 nm, 500 nm, 615 nm, 673 nm, and 870 nm. The Utqiaġvik data are over a 23-year period, and the Atqasuk data cover 11 years. — Time series show the combined aerosol optical depths (AODs) generated for the North Slope of Alaska central facility at Utqiaġvik (top panel) and the Atqasuk site (bottom panel). Gaps in the time series are likely associated with seasonal data availability and quality, as well as required upgrades and replacements of ground-based instruments measuring AOD. Images are courtesy of Gabriel Gibler, Pacific Northwest National Laboratory.

Aerosol Optical Depth Best Estimate 5-Channel (AODBE5CH) production data are now available for the Atmospheric Radiation Measurement (ARM) User Facility’s North Slope of Alaska (NSA) atmospheric observatory.

Scientists can use the AODBE5CH value-added product (VAP) to analyze the variability of aerosol loading over multiple time scales and to study the importance of this variability on atmospheric processes. AODBE5CH merges individual AODs from co-located ARM instruments to produce a high-quality, nearly continuous record of AOD best estimates (also known as combined AODs) at five wavelengths: 415, 500, 615, 673, and 870 nanometers. In addition, AODBE5CH provides wavelength-dependent uncertainty assessments of the combined AODs.

For a 23-year period (1997–2020) at the NSA central facility at Utqiaġvik (formerly known as Barrow), AODBE5CH generated combined AODs from individual spectrally resolved AODs provided by three instruments: the multifilter rotating shadowband radiometer, normal incidence multifilter radiometer, and Cimel sunphotometer.

In addition, AODBE5CH production data are now available for the now-inactive NSA site at Atqasuk for an 11-year period (1999–2010). Those data combine individual spectrally resolved AODs from the multifilter rotating shadowband radiometer and normal incidence multifilter radiometer.

For both sites, the generation of the combined AODs involved spectral and temporal matching of the individual AODs from each instrument.

The output data are in netCDF format with 1-minute temporal resolution.

Scientists can use the new AODBE5CH production data now. Data are available for the NSA central facility from July 30, 1997, to October 14, 2020, and the Atqasuk site from September 5, 1999, to November 14, 2010.

Additional information about the VAP is available on the AODBE web page.

For questions or to provide feedback, please email lead developer Gabriel Gibler or VAP contact Evgueni Kassianov.

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

Data can be referenced as doi:10.5439/1885158.

# # #

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