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Title: A Polarimetric Analysis of Ice Microphysical Processes in Snow, Using Quasi-Vertical Profiles

Abstract

Here, we implement a new quasi-vertical profile (QVP) methodology to investigate the microphysical evolution and significance of intriguing winter polarimetric signatures and their statistical correlations. QVPs of transitional stratiform and pure snow precipitation are analyzed using WSR-88D S-band data, alongside their corresponding environmental thermodynamic High-Resolution Rapid Refresh model analyses. QVPs of K DP and Z DR are implemented to demonstrate their value in interpreting elevated ice processes. Several fascinating and repetitive signatures are observed in the QVPs for differential reflectivity Z DR and specific differential phase K DP, in the dendritic growth layer (DGL), and at the tops of clouds. The most striking feature is maximum Z DR (up to 6 dB) in the DGL occurring near the -10-dB Z ZH contour within low K DP and during shallower and warmer cloud tops. Conversely, maximum K DP (up to 0.3° km -1) in the DGL occurs within low Z DR and during taller and colder cloud tops. Essentially, Z DR and K DP in the DGL are anticorrelated and strongly depend on cloud-top temperature. Analyses also show correlations indicating larger Z DR within lower ZH in the DGL and larger K DP within greater ZH in the DGL. The high-more » Z DR regions are likely dominated by growth of a mixture of highly oblate dendrites and/or hexagonal plates, or prolate needles. Regions of high K DP are expected to be overwhelmed with snow aggregates and crystals with irregular or nearly spherical shapes, seeded at cloud tops. Furthermore, QVP indications of hexagonal plate crystals within the DGL are verified using in situ microphysical measurements, demonstrating the reliability of QVPs in evaluating ice microphysics in upper regions of winter clouds« less

Authors:
 [1];  [2];  [2]
  1. Univ. of Oklahoma, Norman, OK (United States). Cooperative Inst. for Mesoscale Meteorological Studies, and School of Meteorology; National Oceanic and Atmospheric Administration (NOAA), Norman, OK (United States). Oceanic and Atmospheric Research (OAR), National Severe Storms Lab.
  2. Univ. of Oklahoma, Norman, OK (United States). Cooperative Inst. for Mesoscale Meteorological Studies; National Oceanic and Atmospheric Administration (NOAA), Norman, OK (United States). Oceanic and Atmospheric Research (OAR), National Severe Storms Lab.
Publication Date:
Research Org.:
Univ. of Oklahoma, Norman, OK (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1415671
Alternate Identifier(s):
OSTI ID: 1541809
Grant/Contract Number:  
SC0008811
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of Applied Meteorology and Climatology
Additional Journal Information:
Journal Volume: 57; Journal Issue: 1; Journal ID: ISSN 1558-8424
Publisher:
American Meteorological Society
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; meteorology & atmospheric sciences; snow; winter/cool season; cloud microphysics; ice crystals; ice loss/growth; radars/radar observations

Citation Formats

Griffin, Erica M., Schuur, Terry J., and Ryzhkov, Alexander V. A Polarimetric Analysis of Ice Microphysical Processes in Snow, Using Quasi-Vertical Profiles. United States: N. p., 2018. Web. doi:10.1175/jamc-d-17-0033.1.
Griffin, Erica M., Schuur, Terry J., & Ryzhkov, Alexander V. A Polarimetric Analysis of Ice Microphysical Processes in Snow, Using Quasi-Vertical Profiles. United States. doi:10.1175/jamc-d-17-0033.1.
Griffin, Erica M., Schuur, Terry J., and Ryzhkov, Alexander V. Thu . "A Polarimetric Analysis of Ice Microphysical Processes in Snow, Using Quasi-Vertical Profiles". United States. doi:10.1175/jamc-d-17-0033.1.
@article{osti_1415671,
title = {A Polarimetric Analysis of Ice Microphysical Processes in Snow, Using Quasi-Vertical Profiles},
author = {Griffin, Erica M. and Schuur, Terry J. and Ryzhkov, Alexander V.},
abstractNote = {Here, we implement a new quasi-vertical profile (QVP) methodology to investigate the microphysical evolution and significance of intriguing winter polarimetric signatures and their statistical correlations. QVPs of transitional stratiform and pure snow precipitation are analyzed using WSR-88D S-band data, alongside their corresponding environmental thermodynamic High-Resolution Rapid Refresh model analyses. QVPs of KDP and ZDR are implemented to demonstrate their value in interpreting elevated ice processes. Several fascinating and repetitive signatures are observed in the QVPs for differential reflectivity ZDR and specific differential phase KDP, in the dendritic growth layer (DGL), and at the tops of clouds. The most striking feature is maximum ZDR (up to 6 dB) in the DGL occurring near the -10-dBZ ZH contour within low KDP and during shallower and warmer cloud tops. Conversely, maximum KDP (up to 0.3° km-1) in the DGL occurs within low ZDR and during taller and colder cloud tops. Essentially, ZDR and KDP in the DGL are anticorrelated and strongly depend on cloud-top temperature. Analyses also show correlations indicating larger ZDR within lower ZH in the DGL and larger KDP within greater ZH in the DGL. The high-ZDR regions are likely dominated by growth of a mixture of highly oblate dendrites and/or hexagonal plates, or prolate needles. Regions of high KDP are expected to be overwhelmed with snow aggregates and crystals with irregular or nearly spherical shapes, seeded at cloud tops. Furthermore, QVP indications of hexagonal plate crystals within the DGL are verified using in situ microphysical measurements, demonstrating the reliability of QVPs in evaluating ice microphysics in upper regions of winter clouds},
doi = {10.1175/jamc-d-17-0033.1},
journal = {Journal of Applied Meteorology and Climatology},
issn = {1558-8424},
number = 1,
volume = 57,
place = {United States},
year = {2018},
month = {1}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1175/jamc-d-17-0033.1

Citation Metrics:
Cited by: 5 works
Citation information provided by
Web of Science

Figures / Tables:

FIG. 1 FIG. 1: Slant range vs (a) QVP of φDP and (b) φDP along the 220° radial, for KDGX QVP data from 0252 through 0257 UTC 12 Feb 2014, at 10° elevation. The blue-highlighted line represents the interpolated values of φDP between the gates below and above the ML.

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