Interdroplet heterogeneous nucleation of supercooled liquid droplets by solid droplets in oil-in-water emulsions

1994 ◽  
Vol 71 (12) ◽  
pp. 1385-1389 ◽  
Author(s):  
D. J. McClements ◽  
S. -W. Han ◽  
S. R. Dungan
Keyword(s):  
Heterogeneous Nucleation ◽  
Supercooled Liquid ◽  
Liquid Droplets ◽  
Oil In Water

scholarly journals An assessment of cloud top thermodynamic phase products obtained from A-Train passive and active sensors

2013 ◽  
Vol 6 (5) ◽  
pp. 8371-8411 ◽  
Author(s):  
S. Zeng ◽  
J. Riedi ◽  
F. Parol ◽  
C. Cornet ◽  
F. Thieuleux
Keyword(s):  
General Circulation ◽  
Supercooled Liquid ◽  
General Circulation Models ◽  
Global Scale ◽  
Orthogonal Polarization ◽  
Liquid Droplets ◽  
High Confidence ◽  
Cloud Properties ◽  
Fractional Cloud ◽  
Thermodynamic Phase

Abstract. The A-Train observations provide an unprecedented opportunity for the production of high quality dataset describing cloud properties. We illustrate in this study the use of one year of coincident POLDER (Polarization and Directionality of the Earth Reflectance), MODIS (MODerate Resolution Imaging Spectroradiometer) and CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations to establish a reference dataset for the description of cloud top thermodynamic phase at global scale. We present the results of an extensive comparison between POLDER and MODIS cloud top phase products and discuss those in view of cloud vertical structure and optical properties derived simultaneously from collocated CALIOP active measurements. These results allow to identify and quantify potential biases present in the 3 considered dataset. Among those, we discuss the impacts of observation geometry, thin cirrus in multilayered and single layered cloud systems, supercooled liquid droplets, aerosols, fractional cloud cover and snow/ice or bright surfaces on global statistics of cloud phase derived from POLDER and MODIS passive measurements. Based on these analysis we define criteria for the selection of high confidence cloud phase retrievals which in turn can serve for the establishment of a reference cloud phase product. This high confidence joint product derived from POLDER/PARASOL and MODIS/Aqua can be used in the future as a benchmark for the evaluation of other cloud climatologies, for the assessment of cloud phase representation in models and the development of better cloud phase parametrization in the general circulation models (GCMs).

scholarly journals Retrieving Fall Streaks within Cloud Systems Using Doppler Radar

2017 ◽  
Vol 34 (4) ◽  
pp. 905-920 ◽  
Author(s):  
Lukas Pfitzenmaier ◽  
Yann Dufournet ◽  
Christine M. H. Unal ◽  
Herman W. J. Russchenberg
Keyword(s):  
Doppler Radar ◽  
Supercooled Liquid ◽  
Doppler Velocity ◽  
Liquid Droplets ◽  
Cloud Systems ◽  
Retrieval Technique ◽  
Particle Population ◽  
Ice Particles ◽  
New Perspective ◽  
Mixed Phase Clouds

AbstractThe interaction of ice crystals with supercooled liquid droplets in mixed-phase clouds leads to an enhanced growth of ice particles. However, such processes are still not clearly understood although they are important processes for precipitation formation in midlatitudes. To better understand how ice particles grow within such clouds, changes in the microphysical parameters of a particle population falling through the cloud have to be analyzed. The Transportable Atmospheric Radar (TARA) can retrieve the full 3D Doppler velocity vector based on a unique three-beam configuration. Using the derived wind information, a new fall streak retrieval technique is proposed so that microphysical changes along those streaks can be studied. The method is based on Doppler measurements only. The shown examples measured during the Analysis of the Composition of Clouds with Extended Polarization Techniques (ACCEPT) campaign demonstrate that the retrieval is able to capture the fall streaks within different cloud systems. These fall streaks can be used to study changes in a single particle population from its generation (at cloud top) until its disintegration. In this study fall streaks are analyzed using radar moments or Doppler spectra. Synergetic measurements with other instruments during ACCEPT allow the detection of liquid layers within the clouds. The estimated microphysical information is used here to get a better understanding of the influence of supercooled liquid layers on ice crystal growth. This technique offers a new perspective for cloud microphysical studies.

scholarly journals The enhancement and suppression of immersion mode heterogeneous ice-nucleation by solutes

2018 ◽  
Vol 9 (17) ◽  
pp. 4142-4151 ◽  
Author(s):  
Thomas F. Whale ◽  
Mark A. Holden ◽  
Theodore W. Wilson ◽  
Daniel O'Sullivan ◽  
Benjamin J. Murray
Keyword(s):  
Liquid Water ◽  
Heterogeneous Nucleation ◽  
Alkali Halides ◽  
Supercooled Liquid ◽  
Ice Nucleation ◽  
Ammonium Salts ◽  
Atmospherically Relevant ◽  
Heterogeneous Ice Nucleation

Heterogeneous nucleation of ice from supercooled liquid water by some atmospherically relevant nucleators is enhanced by ammonium salts and suppressed by alkali halides.

scholarly journals Observing ice particle growth along fall streaks in mixed-phase clouds using spectral polarimetric radar data

2018 ◽  
Author(s):  
Lukas Pfitzenmaier ◽  
Christine M. H. Unal ◽  
Yann Dufournet ◽  
Herman J. W. Russchenberg
Keyword(s):  
Particle Growth ◽  
Supercooled Liquid ◽  
Radar Data ◽  
Detection Algorithm ◽  
Mixed Phase ◽  
Ice Crystals ◽  
Liquid Droplets ◽  
Growth Processes ◽  
Retrieval Technique ◽  
Mixed Phase Clouds

Abstract. The growth of ice crystals in presence of super-cooled liquid droplets represents the most important process for precipitation formation in the mid-latitudes. Such mixed-phase interaction processes remain however pretty much unknown, as capturing the complexity in cloud dynamics and microphysical variabilities turns to be a real observational challenge. Ground-based radar systems equipped with fully polarimetric and Doppler capabilities in high temporal and spatial resolutions 5 such as the S-band Transportable Atmospheric Radar (TARA) are best suited to observe mixed-phase growth processes. In this paper, measurements are taken with the TARA radar during the ACCEPT campaign (Analysis of the Composition of Clouds with Extended Polarization Techniques). Besides the common radar observables, the 3D wind field is also retrieved due to TARA unique three beam configuration. The novelty of this paper is to combine all these observations with a particle evolution detection algorithm based on a new fall streak retrieval technique in order to study ice particle growth within complex 10 precipitating mixed-phased cloud systems. In the presented cases, three different growth processes of ice crystals, plate-like crystals, and needles, are detected and related to the presence of supercooled liquid water. Moreover, TARA observed signatures are assessed with co-located measurements obtained from a cloud radar and radiosondes. This paper shows that it is possible to observe ice particle growth processes within complex systems taking advantage of adequate technology and state of the art retrieval algorithms. A significant improvement is made towards a conclusive interpretation of ice particle growth processes 15 and their contribution to rain production using fall streak rearranged radar data.

scholarly journals Mechanism of ice nucleation in liquid water on alkali feldspars

2022 ◽  
Author(s):  
Alice Keinert ◽  
Kathrin Deck ◽  
Tilia Gädeke ◽  
Thomas Leisner ◽  
Alexei A. Kiselev
Keyword(s):  
Liquid Water ◽  
Heterogeneous Nucleation ◽  
Supercooled Liquid ◽  
Nucleation Site ◽  
Ice Nucleation ◽  
Natural Environments ◽  
Mineral Surfaces ◽  
Aqueous Interfaces ◽  
Alkali Feldspars

Crystallization of supercooled liquid water in most natural environments starts with heterogeneous nucleation of ice induced by a nucleation site. Mineral surfaces, which form the majority of aqueous interfaces in...

Processing, Characterization and Properties of Specially Constituted Zr-Based Bulk Amorphous Alloys

2010 ◽  
Vol 442 ◽  
pp. 41-51 ◽  
Author(s):  
Muhammad Iqbal ◽  
J.I. Akhter
Keyword(s):  
Amorphous Alloys ◽  
Shear Bands ◽  
Microstructural Characterization ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Liquid Droplets ◽  
Scanning Calorimetry ◽  
Casting Technique ◽  
Stage Crystallization

Bulk metallic glasses (BMGs) are an emerging class of materials. The amorphous alloys have very attractive properties. There is potential for applications. The quaternary and pentanery (ZrCuAlNi)100-xTix (x = 0, 2 and 5 at. %) alloys were synthesized by melting 2-3N pure metals in an arc furnace. Amorphous ingots were produced using Cu mold casting technique. The alloys showed wide supercooled liquid region Tx, high thermal stability and good glass-forming ability (GFA). Many thermal parameters like Trg, , , β and  were measured employing high temperature differential scanning calorimetry (DSC). Structural characterization was carried out by X-ray diffraction (XRD) technique. Microstructural characterization was conducted using high resolution field emission scanning electron microscopy (FESEM) and elemental analysis was done using energy dispersive spectroscopy (EDS). Crystallization behavior and phase formation was studied. Activation energy for crystallization was calculated using Kissinger and Ozawa equations. The alloys show double stage crystallization. Mechanical properties were measured. Compression test was carried out and fracture strength and strain were determined. The fracture behavior was studied which showed veins like patterns, shear bands formation and liquid droplets.

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