Impact of hygroscopic seeding on the initiation of precipitation formation: results of a hybrid bin microphysics parcel model

Abstract. A hybrid bin microphysical scheme is developed in a parcel model framework to study how natural aerosol particles and different types of hygroscopic seeding materials affect the precipitation formation. A novel parameter is introduced to describe the impact of different seeding particles on the evolution of the drop size distribution. The results of more than 100 numerical experiments using the hybrid bin parcel model show that: (a) The Ostwald-ripening effect has a substantial contribution to the broadening of the drop size distribution near the cloud base. The efficiency of this effect increases as the updraft velocity decreases. (b) The efficiency of hygroscopic seeding is significant only if the size of the seeding particles is in the coarse particle size range. The presence of the water-soluble background coarse particles reduces the efficiency of the seeding. (c) The efficient broadening of the size distribution due to the seeding depends on the width of the size distribution of water drops in the control cases, but the relation is not as straightforward as in the case of the glaciogenic seeding.

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Impact of hygroscopic seeding on the initiation of precipitation formation: results of a hybrid bin microphysics parcel model

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-16143-2021 ◽

2021 ◽

Vol 21 (21) ◽

pp. 16143-16159

Author(s):

Istvan Geresdi ◽

Lulin Xue ◽

Sisi Chen ◽

Youssef Wehbe ◽

Roelof Bruintjes ◽

...

Keyword(s):

Size Distribution ◽

Drop Size ◽

Ostwald Ripening ◽

Drop Size Distribution ◽

Water Soluble ◽

Substantial Contribution ◽

Cloud Base ◽

Model Framework ◽

The Impact ◽

Precipitation Formation

Abstract. A hybrid bin microphysical scheme is developed in a parcel model framework to study how natural aerosol particles and different types of hygroscopic seeding materials affect the precipitation formation. A novel parameter is introduced to describe the impact of different seeding particles on the evolution of the drop size distribution. The results of more than 100 numerical experiments using the hybrid bin parcel model show that (a) the Ostwald-ripening effect has a substantial contribution to the broadening of the drop size distribution near the cloud base. The efficiency of this effect increases as the updraft velocity decreases. (b) The efficiency of hygroscopic seeding is significant only if the size of the seeding particles is in the coarse particle size range. The presence of the water-soluble background coarse particles reduces the efficiency of the seeding, (c) The efficient broadening of the size distribution due to the seeding depends on the width of the size distribution of water drops in the control cases, but the relation is not as straightforward as in the case of the glaciogenic seeding.

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Characterization and Simulation of a Low-Pressure Rotator Spray Plate Sprinkler Used in Center Pivot Irrigation Systems

Water ◽

10.3390/w11081684 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1684 ◽

Cited By ~ 4

Author(s):

Cruz Octavio Robles Rovelo ◽

Nery Zapata Ruiz ◽

Javier Burguete Tolosa ◽

Jesús Ramiro Félix Félix ◽

Borja Latorre

Keyword(s):

Drag Coefficient ◽

Distribution Pattern ◽

Size Distribution ◽

Water Distribution ◽

Drop Size ◽

Low Pressure ◽

Drop Size Distribution ◽

Energy Losses ◽

Conventional Model ◽

The Impact

Spray sprinklers enable to operate at low pressures (<103 kPa) in self-propelled irrigation machines. A number of experiments were performed to characterize the water distribution pattern of an isolated rotator spray plate sprinkler operating at very low pressure under different experimental conditions. The experiments were performed under two pressures (69 kPa and 103 kPa) and in calm and windy conditions. The energy losses due to the impact of the out-going jet with the sprinkler plate were measured using an optical technique. The adequacy to reproduce the measured water distribution pattern under calm conditions of two drop size distribution models was evaluated. A ballistic model was used to simulate the water distribution pattern under wind conditions evaluating three different drag models: (1) considering solid spherical drops; (2) a conventional model based on wind velocity and direction distortion pattern, and (3) a new drag coefficient model independent of wind speed. The energy losses measured with the optical method range from 20% to 60% from higher to lower nozzle sizes, respectively, for both evaluated working pressures analyzing over 16,500 droplets. For the drop size distribution selected, Weibull accurately reproduced the water application with a maximum root mean square error (RMSE) of 19%. Up to 28% of the RMSE could be decreased using the wind-independent drag coefficient model with respect to the conventional model; the difference with respect to the spherical model was 4%.

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Drop Size Distribution Characteristics of Typhoon Haishen (2020) in Korea

10.5194/egusphere-egu21-14150 ◽

2021 ◽

Author(s):

Jeong A Kim ◽

Dong-In Lee

Keyword(s):

Size Distribution ◽

Korean Peninsula ◽

Drop Size ◽

Drop Size Distribution ◽

Distribution Characteristics ◽

Azimuthal Direction ◽

Three Stages ◽

Convective Cells ◽

The Impact ◽

Over Time

<p>Recently the frequency of autumn typhoons has increased on the Korean Peninsula and their damage has also increased. The Korea Meteorological Administration (KMA) established a super-strong stage to raise awareness of such a powerful typhoon, Typhoon Haishen (2020). In usual the life cycle of the typhoon is divided into three stages: developing, mature, decaying. To analyze the impact of typhoon Haishen on the Korean Peninsula, this study focused on the landfall and decaying stage. To investigate the microphysical characteristics of the typhoon over time, the drop size distribution (DSD) at the azimuthal direction of the typhoon was studied. DSD variables were obtained by using PARSIVEL (PARticle SIze and VELocity) disdrometers at eleven observation sites from Geoje (34.88&#176;N, 128.57&#176;E) to Ulsan (35.58&#176;N, 129.33&#176;E) that located along the southern coast of Korea. As typhoon Haishen landed at the vicinity of Ulsan (35.3&#176;N,129.3&#176;E), the observation sites were included between the centre of the typhoon and the wind impact radius. Four days before typhoon Haishen landed, typhoon Maysak (2020) landed at the vicinity of Busan (35.4&#176;N,128.9&#176;E) and decayed. The intensity of typhoon Maysak was weakened and the form of convective cells became unclear after landing. Typhoon Haishen was also slightly weakened after landing, however, the form of convective cells and wind impact radius were continuously maintained.</p>

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The Measuring of Sodium Droplet Size Distribution and its Impact on the Consequence of Sodium Spray Fire

Volume 5: Advanced and Next Generation Reactors, Fusion Technology; Codes, Standards, Conformity Assessment, Licensing, and Regulatory Issues ◽

10.1115/icone25-66176 ◽

2017 ◽

Author(s):

Wang Guozhi ◽

Du Haiou ◽

Wang Rongdong ◽

Shi Wentao ◽

Piao Jun

Keyword(s):

Size Distribution ◽

Droplet Size ◽

Input Data ◽

Drop Size ◽

Droplet Size Distribution ◽

Drop Size Distribution ◽

Liquid Sodium ◽

The Real ◽

Temperature And Pressure ◽

The Impact

The sodium droplet size distribution has significant impact on the consequence of sodium spray fire. And it is fundamental input data for the validation and application of sodium spray fire code. The experiments were carried out in a closed vessel to measure the sodium droplet size distribution. Liquid sodium of 250 °C was sprayed downward into the vessel in the form of sodium droplets through a nozzle with a diameter of 2.4mm. The vessel was inerted by argon gas to prevent the sodium droplets from burning. A real time spray droplet sizing system based on ensemble diffraction technique was used to measure the size of the droplets. And the laser beam was passed through two glass windows on the wall of the vessel to reach the sodium droplets. The tests showed that the sizes of the sodium droplets ranged from 184μm to 1000μm at the nozzle pressure of 0.15MPa. And median diameter was 532μm. The sodium spray fire code named NACOM was used to evaluate the impact of particle size distribution on sodium fire. The measured sodium droplets size distribution and the Nukiyama-tanasama drop size distribution were divided into 11 groups to be used as input data for the NACOM code. A comparison showed that 23% of particles in Nukiyama-tanasama drop size distribution were over 1000μm, while the largest size of particles in the measured sodium droplets was 1000μm. The calculation by NACOM code showed that the trend and value of temperature and pressure in the vessel were similar, so to some extent Nukiyama-tanasama drop size distribution is a good approximation of the real sodium droplet size distribution. However, Nukiyama-tanasama drop size distribution may be unsuitable for application in sodium fire safety analysis, because the temperature and pressure calculated from which was lower than that of the real droplet size distribution.

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The impact of the choice of the entire drop size distribution function on Cumulonimbus characteristics

Meteorologische Zeitschrift ◽

10.1127/0941-2948/2009/0366 ◽

2009 ◽

Vol 18 (2) ◽

pp. 207-222 ◽

Cited By ~ 9

Author(s):

Mladjen Ćurić ◽

Dejan Janc ◽

Vladan Vučković ◽

Nemanja Kovačević

Keyword(s):

Distribution Function ◽

Size Distribution ◽

Drop Size ◽

Size Distribution Function ◽

Drop Size Distribution ◽

The Impact

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Drop Size Distribution Variability in Central Argentina during RELAMPAGO-CACTI

Remote Sensing ◽

10.3390/rs13112026 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2026

Author(s):

Candela Casanovas ◽

Paola Salio ◽

Victoria Galligani ◽

Brenda Dolan ◽

Stephen W. Nesbitt

Keyword(s):

Size Distribution ◽

Complex Terrain ◽

Drop Size ◽

Region Of Interest ◽

Bimodal Distribution ◽

Drop Size Distribution ◽

Frequency Distributions ◽

Central Argentina ◽

The Mean ◽

The Impact

The Remote sensing of Electrification, Lightning, And Meso-scale/micro-scale Processes with Adaptive Ground Observations (RELAMPAGO) and the Cloud, Aerosol, and Complex Terrain Interactions Experiment Proposal (CACTI) field campaigns provided an unprecedented thirteen-disdrometer dataset in Central Argentina during the Intensive (IOP, 15 November to 15 December 2018) and Extended (EOP, 15 October 2018 to 30 April 2019) Observational Periods. The drop size distribution (DSD) parameters and their variability were analyzed across the region of interest, which was divided into three subregions characterized by the differing proximity to the Sierras de Córdoba (SDC), in order to assess the impact of complex terrain on the DSD parameters. A rigorous quality control of the data was first performed. The frequency distributions of DSD-derived parameters were analyzed, including the normalized intercept parameter (logNw), the mean volume diameter (D0), the mean mass diameter (Dm), the shape parameter (μ), the liquid water content (LWC), and the rain rate (R). The region closest to the SDC presented higher values of logNw, lower D0, and higher μ, while the opposite occurred in the farthest region, i.e., the concentration of small drops decreased while the concentration of bigger drops increased with the distance to the east of the SDC. Furthermore, the region closest to the SDC showed a bimodal distribution of D0: the lower values of D0 were associated with higher values of logNw and were found more frequently during the afternoon, while the higher D0 were associated with lower logNw and occurred more frequently during the night. The data were analyzed in comparison to the statistical analysis of Dolan et al. 2018 and sorted according to the classification proposed in the cited study. The logNw-D0 and LWC-D0 two-dimensional distributions allowed further discussion around the applicability of other mid-latitude and global precipitation classification schemes (startiform/convection) in the region of interest. Finally, three precipitation case studies were analyzed with supporting polarimetric radar data in order to relate the DSD characteristics to the precipitation type and the microphysical processes involved in each case.

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