Multiparameter Radar Measurements in Colorado Convective Storms. Part I: Graupel Melting Studies

Bringi, V. N.; Rasmussen, Roy; Vivekanandan, J.

doi:10.1175/1520-0469(1986)043<2545:mrmicc>2.0.co;2

Cited by 65 publications

(49 citation statements)

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“…For conical shapes, we assumed a random uniform distribution between 0.75 and 1.1 for the axis ratio (Heymsfield, 1978), and a zero-mean Gaussian distribution for canting angle, with randomly varying standard deviation between 0 and 30 • . For spheroidal shapes, the canting angle standard deviation varied between 0 and 15 • , and the axis ratio between 0.9 and 1 (Prupaccher and Klett, 1978;Aydin and Seliga, 1984;Straka et al, 2000;Bringi et al, 1986). Figure 1 shows the output of simulated DP radar observables (obtained from 1000 iterations) for spheroidal (a, c), and conical (b, d) shaped graupel.…”

Section: Hca Optimization For Graupel Identificationmentioning

confidence: 99%

Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1

et al. 2016

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Abstract.A multi-sensor analysis of convective precipitation events that occurred in central Italy in autumn 2012 during the HyMeX (Hydrological cycle in the Mediterranean experiment) Special Observation Period (SOP) 1.1 is presented. Various microphysical properties of liquid and solid hydrometeors are examined to assess their relationship with lightning activity. The instrumentation used consisted of a C-band dual-polarization weather radar, a 2-D video disdrometer, and the LINET lightning network. Results of Tmatrix simulation for graupel were used to (i) tune a fuzzy logic hydrometeor classification algorithm based on Liu and Chandrasekar (2000) for the detection of graupel from Cband dual-polarization radar measurements and (ii) to retrieve graupel ice water content. Graupel mass from radar measurements was related to lightning activity. Three significant case studies were analyzed and linear relations between the total mass of graupel and number of LINET strokes were found with different slopes depending on the nature of the convective event (such as updraft strength and freezing level height) and the radar observational geometry. A high coefficient of determination (R 2 = 0.856) and a slope in agreement with satellite measurements and model results for one of the case studies (15 October 2012) were found. Results confirm that one of the key features in the electrical charging of convective clouds is the ice content, although it is not the only one. Parameters of the gamma raindrop size distribution measured by a 2-D video disdrometer revealed the transition from a convective to a stratiform regime. The raindrop size spectra measured by a 2-D video disdrometer were used to partition rain into stratiform and convective classes. These results are further analyzed in relation to radar measurements and to the number of strokes. Lightning activity was not always recorded when the precipitation regime was classified as convective rain. High statistical scores were found for relationships relating lightning activity to graupel aloft.

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Section: Hca Optimization For Graupel Identificationmentioning

confidence: 99%

Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1

et al. 2016

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“…Understanding the microphysical properties of melting hydrometeors and their scattering and propagation effects is of great importance in accurately estimating parameters of the precipitation from spaceborne radar and radiometers (Bringi et al 1986;Fabry and Szymer 1999;Olsen et al, 2001a and2001b;Meneghini and Liao 2000;Liao and Meneghini 2005;Sassen et al, 2005 and). These instruments include the Precipitation Radar (PR) and the TRMM Microwave Imager (TMI) on the Tropical Rainfall Measuring Mission (TRMM) and the Dual-wavelength Precipitation Radar (DPR) and GPM Microwave Imager (GMI) on the proposed Global Precipitation Measuring (GPM).…”

Section: Introductionmentioning

confidence: 99%

Measurements and Simulations of Nadir-Viewing Radar Returns from the Melting Layer at X and W Bands

Liao

Meneghini

Tian

et al. 2009

Journal of Applied Meteorology and Climatology

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Simulated radar signatures within the melting layer in stratiform rain, namely the radar bright band, are checked by means of comparisons with simultaneous measurements of the bright band made by the EDOP (X-band) and CRS (W-band) airborne Doppler radars during the CRYSTAL-FACE campaign in 2002. A stratified-sphere model, allowing the fractional water content to vary along the radius of the particle, is used to compute the scattering properties of individual melting snowflakes. Using the effective dielectric constants computed by the conjugate gradient-fast Fourier transform (CGFFT) numerical method for X and W bands, and expressing the fractional water content of melting particle as an exponential function in particle radius, it is found that at X band the simulated radar bright-band profiles are in an excellent agreement with the measured profiles. It is also found that the simulated W-band profiles usually resemble the shapes of the measured bright-band profiles even though persistent offsets between them are present. These offsets, however, can be explained by the attenuation caused by cloud water and water vapor at W band. This is confirmed by the comparisons of the radar profiles made in the rain regions where the un-attenuated W-band reflectivity profiles can be estimated through the X-and Wband Doppler velocity measurements. The bright-band model described in this paper has the potential to be used effectively for both radar and radiometer algorithms relevant to the TRMM and GPM satellite missions

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“…This is due to the extensive observation of rain medium over a decade using several polarimetric radars and surface and airborne in situ measuring devices [1J- [5]. Theoretical calculation and radar observations suggest that the polarimetric measurements of reflectivity factor at horizontal polarization (ZH) differential reflectivity (ZDR) and specific differential phase (K DP) lie in a limited three-dimensional space for rain medium.…”

Section: Introduction Pmentioning

confidence: 99%

Self-consistency of polarization diversity measurement of rainfall

Scarchilli¹,

Gorgucci²,

Chandrasekar

et al. 1996

IEEE Trans. Geosci. Remote Sensing

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Abstract-Polarization diversity measurements of rainfall, namely the reflectivity factor, differential reflectivity, and specific differential propagation phase, vary in a constrained three-dimensional space. Algorithms are derived to quantify this self-consistency of measurements. In particular, estimation of the specific differential propagation phase shift based on reflectivity and differential reflectivity is analyzed in detail. Theoretical simulation as well as radar observations of rainfall at S (CSU-CHILL) and C (Polar SSC) bands are used to demonstrate that the range profiles of differential propagation shift can be constructed from measurements. of reflectivity and differential reflectivity.

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Multiparameter Radar Measurements in Colorado Convective Storms. Part I: Graupel Melting Studies

Cited by 65 publications

References 0 publications

Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1

Multi-sensor analysis of convective activity in central Italy during the HyMeX SOP 1.1

Measurements and Simulations of Nadir-Viewing Radar Returns from the Melting Layer at X and W Bands

Self-consistency of polarization diversity measurement of rainfall

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