NWC REU 2012
May 21 - July 31



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Intercomparison of Vertical Structure of Storms Revealed by Ground-based (NMQ) and Spaceborne Radars (CloudSat-CPR and TRMM-PR)

Veronica Fall, Yang Hong, Qing Cao, and Nicole Grams


What is already known:

  • Microphysical processes in the sub-freezing region are highly related to the precipitation on the surface.
  • Understanding these processes may improve the microphysical modeling and quantitative precipitation estimation.
  • Multi-frequency observations from ground-based and spaceborne radars provide informative details of microphysical structure of cloud and precipitation.

What this study adds:

  • The intercomparison of S-band, W-band, and Ku-band radar observations demonstrates multi-frequency scattering characteristics of various hydrometeors.
  • Vertical profile of radar reflectivity reveals the vertical evolution of a cold-season storm. Identification of melting layer is important to understanding the vertical structure of winter storms.


Spaceborne radars provide great opportunities to investigate the vertical structure of clouds and precipitation. Two typical spaceborne radars for such a study are the W–band Cloud Profiling Radar (CPR) and Ku–band Precipitation Radar (PR), which are onboard NASA’s CloudSat and TRMM satellites, respectively. Compared to S–band ground–based radars, they have distinct scattering characteristics for different hydrometeors in clouds and precipitation. The combination of spaceborne and ground–based radar observations can help the identification of hydrometeors and improve the radar–based quantitative precipitation estimation (QPE). This study analyzes the vertical structure of the 18 January 2009 storm using data from the CloudSat CPR, TRMM PR, and a NEXRAD–based National Mosaic and Multisensor QPE (NMQ) system. Microphysics above, within, and below the melting layer are studied through an intercomparison of multi–frequency measurements. Hydrometeors’ type and their radar scattering characteristics are analyzed. Additionally, the study of the vertical profile of reflectivity (VPR) reveals the brightband properties in the cold–season precipitation and its effect on the radar–based QPE. In all, the joint analysis of spaceborne and ground–based radar data increases the understanding of the vertical structure of storm systems and provides a good insight into the microphysical modeling for weather forecasts.

Full Paper [PDF]