Lidar and Radar Measurements of the melting layer in the frame of the Convective and Orographically‐induced Precipitation Study

2009 ◽  
Author(s):  
Paolo Di Girolamo ◽  
Donato Summa ◽  
Rohini Bhawar ◽  
Tatiana Di Iorio ◽  
Geraint Vaughan ◽  
...  
Keyword(s):  
Melting Layer ◽  
Radar Measurements

scholarly journals Characterization of S-Band Dual-Polarized Radar Data for the Convective Rain Melting Layer Detection in A Tropical Region

2018 ◽  
Vol 10 (11) ◽  
pp. 1740 ◽  
Author(s):  
Feng Yuan ◽  
Yee Lee ◽  
Yu Meng ◽  
Jin Ong
Keyword(s):  
Radar Data ◽  
Tropical Region ◽  
Rain Event ◽  
Melting Layer ◽  
Convective Rain ◽  
Radar Measurements ◽  
Dual Polarized ◽  
Rain Events ◽  
Differential Reflectivity

In the tropical region, convective rain is a dominant rain event. However, very little information is known about the convective rain melting layer. In this paper, S-band dual-polarized radar data is studied in order to identify both the stratiform and convective rain melting layers in the tropical region, with a focus on the convective events. By studying and analyzing the above-mentioned two types of rain events, amongst three radar measurements of reflectivity ( Z ), differential reflectivity ( Z DR ), and cross correlation coefficient ( ρ HV ), the latter one is the best indicator for convective rain melting layer detection. From two years (2014 and 2015) of radar and radiosonde observations, 13 convective rain melting layers are identified with available 0 °C isothermal heights which are derived from radiosonde vertical profiles. By comparing the melting layer top heights with the corresponding 0 °C isothermal heights, it is found that for convective rain events, the threshold to detect melting layer should be modified to ρ HV = 0.95 for the tropical region. The melting layer top and bottom heights are then estimated using the proposed threshold, and it is observed from this study that the thickness of convective rain melting layer is around 2 times that of stratiform rain melting layer which is detected by using the conventional ρ HV = 0.97 .

scholarly journals Lidar and radar measurements of the melting layer: observations of dark and bright band phenomena

2012 ◽  
Vol 12 (9) ◽  
pp. 4143-4157 ◽  
Author(s):  
P. Di Girolamo ◽  
D. Summa ◽  
M. Cacciani ◽  
E. G. Norton ◽  
G. Peters ◽  
...  
Keyword(s):  
Rain Event ◽  
Melting Layer ◽  
Bright Band ◽  
Lidar Measurements ◽  
Multi Wavelength ◽  
Radar Measurements ◽  
Uhf Wind Profiler ◽  
The University ◽  
University Of Manchester

Abstract. Multi-wavelength lidar measurements in the melting layer revealing the presence of dark and bright bands have been performed by the University of BASILicata Raman lidar system (BASIL) during a stratiform rain event. Simultaneously radar measurements have been also performed from the same site by the University of Hamburg cloud radar MIRA 36 (35.5 GHz), the University of Hamburg dual-polarization micro rain radar (24.15 GHz) and the University of Manchester UHF wind profiler (1.29 GHz). Measurements from BASIL and the radars are illustrated and discussed in this paper for a specific case study on 23 July 2007 during the Convective and Orographically-induced Precipitation Study (COPS). Simulations of the lidar dark and bright band based on the application of concentric/eccentric sphere Lorentz-Mie codes and a melting layer model are also provided. Lidar and radar measurements and model results are also compared with measurements from a disdrometer on ground and a two-dimensional cloud (2DC) probe on-board the ATR42 SAFIRE. Measurements and model results are found to confirm and support the conceptual microphysical/scattering model elaborated by Sassen et al. (2005).

scholarly journals WRF–SBM Simulations of Melting-Layer Structure in Mixed-Phase Precipitation Events Observed during LPVEx

2014 ◽  
Vol 53 (12) ◽  
pp. 2710-2731 ◽  
Author(s):  
Takamichi Iguchi ◽  
Toshihisa Matsui ◽  
Wei-Kuo Tao ◽  
Alexander P. Khain ◽  
Vaughan T. J. Phillips ◽  
...  
Keyword(s):  
Liquid Water ◽  
Large Diameter ◽  
Mixed Phase ◽  
Doppler Velocity ◽  
Gradual Change ◽  
Phase Precipitation ◽  
Melting Layer ◽  
Validation Experiment ◽  
Radar Measurements ◽  
Precipitation Events

AbstractTwo mixed-phase precipitation events were observed on 21 September and 20 October 2010 over the southern part of Finland during the Light Precipitation Validation Experiment (LPVEx). These events have been simulated using the Weather Research and Forecasting Model coupled with spectral bin microphysics (WRF–SBM). The detailed ice-melting scheme with prognosis of the liquid water fraction during melting enables explicit simulation of microphysical properties in the melting layer. First, the simulations have been compared with C-band 3D radar measurements for the purpose of evaluating the overall profiles of cloud and precipitation. The simulation has some artificial convective patterns and errors in the forecast displacement of the precipitation system. The overall overestimation of reflectivity is consistent with a bias toward the range characterized by large-diameter droplets in the surface drop size distribution. Second, the structure of the melting bands has been evaluated against vertically pointing K-band radar measurements. A peak in reflectivity and a gradual change in Doppler velocity are observed and similarly simulated in the common temperature range from approximately 0° to 3°C. The effectiveness of the time-dependent melting scheme has been justified by intercomparison with a corresponding simulation using an instantaneous melting scheme. A weakness of the new melting scheme is that melting particles having high liquid water fractions on the order of 80%–90% cannot be simulated. This situation may cause underestimation of radar reflectivity in the melting layer because of the assumptions of melting-particle structure used to calculate the scattering properties.

scholarly journals Lidar and radar measurements of the melting layer in the frame of the Convective and Orographically-induced Precipitation Study: observations of dark and bright band phenomena

2011 ◽  
Vol 11 (11) ◽  
pp. 30949-30987
Author(s):  
P. Di Girolamo ◽  
D. Summa ◽  
R. Bhawar ◽  
T. Di Iorio ◽  
E. G. Norton ◽  
...  
Keyword(s):  
Raman Lidar ◽  
Layer Model ◽  
Lidar System ◽  
Melting Layer ◽  
Cloud Radar ◽  
Bright Band ◽  
Radar Measurements ◽  
Uhf Wind Profiler ◽  
The University ◽  
University Of Manchester

Abstract. During the Convective and Orographically-induced Precipitation Study (COPS), lidar dark and bright bands were observed by the University of BASILicata Raman lidar system (BASIL) during several intensive (IOPs) and special (SOPs) observation periods (among others, 23 July, 15 August, and 17 August 2007). Lidar data were supported by measurements from the University of Hamburg cloud radar MIRA 36 (36 GHz), the University of Hamburg dual-polarization micro rain radars (24.1 GHz) and the University of Manchester UHF wind profiler (1.29 GHz). Results from BASIL and the radars for 23 July 2007 are illustrated and discussed to support the comprehension of the microphysical and scattering processes responsible for the appearance of the lidar and radar dark and bright bands. Simulations of the lidar dark and bright band based on the application of concentric/eccentric sphere Lorentz-Mie codes and a melting layer model are also provided. Lidar and radar measurements and model results are also compared with measurements from a disdrometer on ground and a two-dimensional cloud (2DC) probe on-board the ATR42 SAFIRE.

scholarly journals Identification of the Melting Layer through Dual-Polarization Radar Measurements at Vertical Incidence

2006 ◽  
Vol 23 (6) ◽  
pp. 829-839 ◽  
Author(s):  
Luca Baldini ◽  
Eugenio Gorgucci
Keyword(s):  
Standard Deviation ◽  
Case Studies ◽  
Doppler Radar ◽  
Convective Precipitation ◽  
Doppler Velocity ◽  
Polarimetric Radar ◽  
Dual Polarization ◽  
Physical Processes ◽  
Melting Layer ◽  
Radar Measurements

Abstract Features of the melting layer of precipitation such as height and thickness are important in many meteorological applications. Doppler radar observations with a vertically pointing antenna have often been used in order to derive these features and to investigate the physical processes governing formation of the precipitation. This paper presents a technique to detect the characteristics of the melting layer based on the standard deviation of polarimetric radar measurements taken at vertical incidence. Using two case studies with stratiform and convective precipitation, the proposed technique is compared with conventional techniques based on reflectivity and mean Doppler velocity profiles. Data presented in this paper were obtained by the coherent dual-polarization C-band radar, Polar 55C, in Rome, Italy, during the summer and the fall of 2004.

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