Journal cover Journal topic
Atmospheric Measurement Techniques An interactive open-access journal of the European Geosciences Union

Journal metrics

  • IF value: 3.089 IF 3.089
  • IF 5-year<br/> value: 3.700 IF 5-year
    3.700
  • CiteScore<br/> value: 3.59 CiteScore
    3.59
  • SNIP value: 1.273 SNIP 1.273
  • SJR value: 2.026 SJR 2.026
  • IPP value: 3.082 IPP 3.082
  • h5-index value: 45 h5-index 45
https://doi.org/10.5194/amt-2017-485
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
03 Jan 2018
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Measurement Techniques (AMT).
Snowfall retrieval at X, Ka and W band: consistency of backscattering and microphysical properties using BAECC ground-based measurements
Marta Tecla Falconi1, Annakaisa von Lerber2, Davide Ori3, Frank Silvio Marzano1, and Dmitri Moisseev2,4 1Department of Information Engineering, Sapienza University of Rome, Italy and CETEMPS, L’Aquila, Italy
2Finnish Meteorological Institute, Finland
3Institute for Geophysics and Meteorology, University of Cologne, Cologne, Germany
4Department of Physics, University of Helsinki, Finland
Abstract. Radar-based snowfall intensity retrieval is investigated at centimeter and millimeter wavelengths using high-quality collocated ground-based multi-frequency radar and video-disdrometer observations. Using data from four snowfall events, recorded during the Biogenic Aerosols Effects on Clouds and Climate (BAECC) campaign in Finland, measurements of liquid-water-equivalent snowfall rate S are correlated to radar equivalent reflectivity factors Ze, measured by the Atmospheric Radiation Measurement (ARM) cloud radars operating at X, Ka and W frequency bands. From these coupled observations power-law Ze-S relationships are derived for all considered frequencies and distinguishing fluffy from rimed snowfall. Interestingly fluffy-snow events show a spectrally distinct signature of Ze-S with respect to rimed-snow cases. In order to understand the connection between snowflake microphysical and multi-frequency backscattering properties, numerical simulations are also performed by using the particle size distribution provided by the in-situ video-disdrometer. The latter are carried out by using both the T-matrix method (TMM) for soft-spheroids with different aspect ratios and exploiting a pre-computed discrete dipole approximation (DDA) database for complex-shape snowflakes. Based on the presented results, it is concluded that the soft-spheroid approximation can be adopted to explain the observed multi-frequency Ze-S relations if a proper spheroid aspect ratio is selected. The latter may depend on the snowfall type. A further analysis of the backscattering simulations reveals that TMM cross-sections are higher than the DDA ones for small ice particles, but lower for larger particles. These differences may explain why the soft-spheroid approximation is satisfactory for radar reflectivity simulations, the errors of computed cross-sections for larger and smaller particles compensating each other.

Citation: Falconi, M. T., von Lerber, A., Ori, D., Marzano, F. S., and Moisseev, D.: Snowfall retrieval at X, Ka and W band: consistency of backscattering and microphysical properties using BAECC ground-based measurements, Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2017-485, in review, 2018.
Marta Tecla Falconi et al.
Marta Tecla Falconi et al.
Marta Tecla Falconi et al.

Viewed

Total article views: 160 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
124 34 2 160 1 4

Views and downloads (calculated since 03 Jan 2018)

Cumulative views and downloads (calculated since 03 Jan 2018)

Viewed (geographical distribution)

Total article views: 160 (including HTML, PDF, and XML)

Thereof 160 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 16 Jan 2018
Publications Copernicus
Download
Short summary
Estimate snowfall intensity from satellite and ground-based radar missions requires accurate retrieval models. Reflectivity-snowfall relations are obtained at cm- and mm-wavelengths using data from snowfall events, recorded during the Biogenic Aerosols Effects on Clouds and Climate (BAECC) campaign in Finland. Fluffy and rimed snowfall cases are identified. Numerical simulations are performed to relate snowflake microphysical (from video-disdrometer) and multifrequency backscattering properties.
Estimate snowfall intensity from satellite and ground-based radar missions requires accurate...
Share