wacr > W-Band (95 GHz) ARM Cloud RadarInstrument Type(s) > Baseline

The W-band ARM Cloud Radar (WACR) systems are zenith-pointing Doppler radars that probe the extent and composition of clouds at 95.04 GHz.

The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops).

This radar reports estimates for the first three spectra moments for each range gate up to 15 km. The 0th moment is reflectivity, the 1st moment is radial velocity, and the 2nd moment is spectral width. Also available are the raw spectra files.

Unlike the millimeter wavelength cloud radar (MMCR), the WACR does not use pulse coding and operates in only copolarization and cross-polarization modes.



  • Fixed
  • AMF1
  • AMF2
  • AMF3


Eissner J, D Mechem, M Jensen, and S Giangrande. 2021. "Factors Governing Cloud Growth and Entrainment Rates in Shallow Cumulus and Cumulus Congestus during GoAmazon2014/5." Journal of Geophysical Research: Atmospheres, 126(12), e2021JD034722, 10.1029/2021JD034722.
Research Highlight

Biscaro T, L Machado, S Giangrande, and M Jensen. 2021. "What drives daily precipitation over the central Amazon? Differences observed between wet and dry seasons." Atmospheric Chemistry and Physics, 21(9), 10.5194/acp-21-6735-2021.
Research Highlight

Theisen A, A Lindenmaier, J Mather, J Comstock, S Collis, and S Giangrande. 2021. ARM FY2021 Radar Plan. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-269.

Lee H, A Fridlind, and A Ackerman. 2021. "An evaluation of size-resolved cloud microphysics scheme numerics for use with radar observations Part II: Condensation and evaporation." Journal of the Atmospheric Sciences, 76(1), 10.1175/JAS-D-20-0213.1.

Tian Y, Y Zhang, S Klein, and C Schumacher. 2021. "Interpreting the diurnal cycle of clouds and precipitation in the ARM GoAmazon observations: Shallow to deep convection transition." Journal of Geophysical Research: Atmospheres, 126(5), 2020JD033766, 10.1029/2020JD033766.
Research Highlight

Matrosov S. 2021. "Polarimetric Radar Variables in Snowfall at Ka- and W-Band Frequency Bands: A Comparative Analysis." Journal of Atmospheric and Oceanic Technology, 38(1), 10.1175/JTECH-D-20-0138.1.
Research Highlight

Geerts B, G McFarquhar, L Xue, M Jensen, P Kollias, M Ovchinnikov, M Shupe, P DeMott, Y Wang, M Tjernstrom, P Field, S Abel, T Spengler, R Neggers, S Crewell, M Wendisch, and C Lupkes. 2021. Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) Field Campaign Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-001.


Wang D, M Jensen, J D'Iorio, G Jozef, S Giangrande, K Johnson, Z Luo, M Starzec, and G Mullendore. 2020. "An Observational Comparison of Level of Neutral Buoyancy and Level of Maximum Detrainment in Tropical Deep Convective Clouds." Journal of Geophysical Research: Atmospheres, 125(16), e2020JD032637, 10.1029/2020JD032637.
Research Highlight

Vilà‐Guerau de Arellano J, X Wang, X Pedruzo‐Bagazgoitia, M Sikma, A Agustí‐Panareda, S Boussetta, G Balsamo, L Machado, T Biscaro, P Gentine, S Martin, J Fuentes, and T Gerken. 2020. "Interactions Between the Amazonian Rainforest and Cumuli Clouds: A Large‐Eddy Simulation, High‐Resolution ECMWF, and Observational Intercomparison Study." Journal of Advances in Modeling Earth Systems, 12(7), e2019MS001828, 10.1029/2019MS001828.

Joshil S, V Chandrasekar, J Chiu, and Y Blanchard. 2020. "Separating cloud and drizzle signals in radar Doppler spectra using a parametric time domain method." Journal of Atmospheric and Oceanic Technology, 37(9), 10.1175/JTECH-D-20-0061.1.

View All Related Publications