TY - JOUR
T1 - Insights into riming and aggregation processes as revealed by aircraft, radar, and disdrometer observations for a 27 April 2011 widespread precipitation event
AU - Giangrande, Scott E.
AU - Toto, Tami
AU - Bansemer, Aaron
AU - Kumjian, Matthew R.
AU - Mishra, Subhashree
AU - Ryzhkov, Alexander V.
N1 - Funding Information:
3.3. ARM CSAPR: Observations and Interpretation Supported by Aircraft
Funding Information:
This manuscript has been authored by employees of Brookhaven Science Associates, LLC under contract DE-AC02-98CH10886 with the U.S. Department of Energy. Bansemer was partially supported by DOE ASR grant DE SC0008648. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. Financial support for A. Ryzhkov, M. Kumjian, and S. Mishra was provided through the grant ER65459 from the U.S. Department of Energy Atmospheric System Research Program and from NOAA Office of Atmospheric Research under NOAA University of Oklahoma Cooperative Agreement NA11OAR4320072, U.S. Department of Commerce. The authors wish to thank the ARM Climate Research Facility for the extended KAZR, disdrometer, CSAPR, and RWP data sets (Instrument mentors Nitin Bharadwaj, Scott Collis, Mary Jane Bartholomew, and Richard Coulter) collection, products and maintenance, and the crew and scientists of the University of North Dakota Citation aircraft. Special thanks also to David Delene (UND) for his helpful discussions on the Citation probes and their uncertainties. We would also like to thank the efforts of Edward Luke, Karen Johnson, Michael Jensen, Isztar Zawadzki, and Mariko Oue for ARM KAZR moment and Doppler spectral processing products and associated discussions on spectral signatures.
Publisher Copyright:
© 2016. American Geophysical Union. All Rights Reserved.
PY - 2016
Y1 - 2016
N2 - This study presents aircraft spiral ascent and descent observations intercepting a transition to riming processes during widespread stratiform precipitation. The sequence is documented using collocated scanning and profiling radar, including longer-wavelength dual polarization measurements and shorter-wavelength Doppler spectra. Riming regions are supported using aircraft measurements recording elevated liquid water concentrations, spherical particle shapes, and saturationwith respect to water. Profiling cloud radar observations indicate riming regions during the event as having increasing particle fall speeds, rapid time-height changes, and bimodalities in Doppler spectra. These particular riming signatures are coupled to scanning dual polarization radar observations of higher differential reflectivity (ZDR) aloft. Reduced melting layer enhancements and delayed radar bright-band signatures in the column are also observed during riming periods, most notably with the profiling radar observations. The bimodal cloud radar Doppler spectra captured near riming zones indicate two time-height spectral ice peaks, one rimed particle peak, and one peak associated with pristine ice needle generation and/or growth between -4°C and -7°C also sampled by aircraft probes. This pristine needle population gives a partial explanation for the enhanced ZDR we observe near this rimed particle region. The riming signatures aloft and radar measurements within the melting level are weakly lag correlated (r~0.6) with smallermedian drop sizes at the surface, as compared with later times when aggregation of larger particle sizes was believed dominant.
AB - This study presents aircraft spiral ascent and descent observations intercepting a transition to riming processes during widespread stratiform precipitation. The sequence is documented using collocated scanning and profiling radar, including longer-wavelength dual polarization measurements and shorter-wavelength Doppler spectra. Riming regions are supported using aircraft measurements recording elevated liquid water concentrations, spherical particle shapes, and saturationwith respect to water. Profiling cloud radar observations indicate riming regions during the event as having increasing particle fall speeds, rapid time-height changes, and bimodalities in Doppler spectra. These particular riming signatures are coupled to scanning dual polarization radar observations of higher differential reflectivity (ZDR) aloft. Reduced melting layer enhancements and delayed radar bright-band signatures in the column are also observed during riming periods, most notably with the profiling radar observations. The bimodal cloud radar Doppler spectra captured near riming zones indicate two time-height spectral ice peaks, one rimed particle peak, and one peak associated with pristine ice needle generation and/or growth between -4°C and -7°C also sampled by aircraft probes. This pristine needle population gives a partial explanation for the enhanced ZDR we observe near this rimed particle region. The riming signatures aloft and radar measurements within the melting level are weakly lag correlated (r~0.6) with smallermedian drop sizes at the surface, as compared with later times when aggregation of larger particle sizes was believed dominant.
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U2 - 10.1002/2015JD024537
DO - 10.1002/2015JD024537
M3 - Article
AN - SCOPUS:85029386720
VL - 121
SP - 5846
EP - 5863
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
SN - 2169-897X
IS - 10
ER -