Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

rlprof-fex > Raman Lidar Vertical Profiles Feature Detection and ExtinctionVAP Type(s) > Baseline

The Raman Lidar Feature detection and EXtinction (FEX) VAP provides height- and time-resolved estimates of cloud and aerosol optical properties. These include estimates of aerosol backscatter coefficient, extinction, scattering ratio, lidar ratio, and linear depolarization ratio. The VAP also provides feature masks that can be used to identify regions containing ice or liquid clouds. The nominal temporal resolution is 2 min, and the nominal vertical resolution is 30 m. Data coverage for the aerosol optical properties (i.e., backscatter, extinction, scattering ratio, and lidar ratio) generally ranges from roughly 200 m to 4 km above the surface, whereas cloud properties such as the cloud mask and the linear depolarization can be reliably estimated below roughly 18 km. With careful quality control the output from this VAP can be used by scientists for process studies, climatology development, instrument intercomparison studies, and model validation.


  • Fixed
  • AMF1
  • AMF2
  • AMF3

Active Locations

Facility Name Start Date
Graciosa Island, Azores, Portugal 2015-09-04
Central Facility, Lamont, OK 2016-01-14


Balmes K, Q Fu, and T Thorsen. 2021. "The diurnal variation of the aerosol optical depth at the ARM SGP site." Earth and Space Science, , 10.1029/2021EA001852. ONLINE.


Dawson K, R Ferrare, R Moore, M Clayton, T Thorsen, and E Eloranta. 2020. "Ambient Aerosol Hygroscopic Growth From Combined Raman Lidar and HSRL." Journal of Geophysical Research: Atmospheres, 125(7), e2019JD031708, 10.1029/2019JD031708.


Chand D, R Newsom, T Thorsen, E Cromwell, C Sivaraman, C Flynn, J Shilling, and J Comstock. 2019. Aerosol and Cloud Optical Properties from the ARM Raman Lidars: The Feature Detection and Extinction (FEX) Value-Added Product. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-224.

Balmes K, Q Fu, and T Thorsen. 2019. "Differences in Ice Cloud Optical Depth From CALIPSO and Ground-Based Raman Lidar at the ARM SGP and TWP Sites." Journal of Geophysical Research: Atmospheres, 124(3), 10.1029/2018JD028321.


Balmes K and Q FU. 2018. "An Investigation of Optically Very Thin Ice Clouds from Ground-Based ARM Raman Lidars." Atmosphere, 9(11), 10.3390/atmos9110445.

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Damao Zhang
Pacific Northwest National Laboratory

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