scholarly journals Influence of the ice growth rate on the incorporation of gaseous HCl

2004 ◽  
Vol 4 (4) ◽  
pp. 4719-4736 ◽  
Author(s):  
F. Domine ◽  
C. Rauzy
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Growth Mechanism ◽  
Laboratory Experiments ◽  
Ice Crystals ◽  
Ice Growth ◽  
A Value ◽  
Physical Variables ◽  
Hcl Concentration ◽  
Cloud Ice

Abstract. Ice crystals were grown in the laboratory at −15°C, at different growth rates and in the presence of a partial pressure of HCl of 1.63×10−3 Pa, to test whether the ice growth rate influences the amount of HCl taken up, XHCl, as predicted by the ice growth mechanism of Domine and Thibert (1996). The plot of HCl concentration in ice as a function of growth rate has the aspect predicted by that mechanism: XHCl decreases with increasing growth rate, from a value that depends on thermodynamic equilibrium to a value that depends only on kinetic factors. The height of the growth steps of the ice crystals is determined to be about 1.5 nm from these experiments. We discuss that the application of these laboratory experiments to cloud ice crystals and to snow metamorphism is not quantitatively possible at this stage, because the physical variables that determine crystal growth in nature, and in particular the step height, are not known. Qualitative applications are attempted for HCl and HNO3 incorporation in cloud ice and snowpack crystals.

scholarly journals Influence of the ice growth rate on the incorporation of gaseous HCl

2004 ◽  
Vol 4 (11/12) ◽  
pp. 2513-2519 ◽  
Author(s):  
F. Domine ◽  
C. Rauzy
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Growth Mechanism ◽  
Laboratory Experiments ◽  
Ice Crystals ◽  
Ice Growth ◽  
A Value ◽  
Physical Variables ◽  
Hcl Concentration ◽  
Cloud Ice

Abstract. Ice crystals were grown in the laboratory at −15°C, at different growth rates and in the presence of a partial pressure of HCl of 1.63×10-3 Pa, to test whether the ice growth rate influences the amount of HCl taken up, XHCl, as predicted by the ice growth mechanism of Domine and Thibert (1996). The plot of HCl concentration in ice as a function of growth rate has the aspect predicted by that mechanism: XHCl decreases with increasing growth rate, from a value that depends on thermodynamic equilibrium to a value that depends only on kinetic factors. The height of the growth steps of the ice crystals is determined to be about 150 nm from these experiments. We discuss that the application of these laboratory experiments to cloud ice crystals and to snow metamorphism is not quantitatively possible at this stage, because the physical variables that determine crystal growth in nature, and in particular the step height, are not known. Qualitative applications are attempted for HCl and HNO3 incorporation in cloud ice and snowpack crystals.

scholarly journals Crystal growth rates in polar firn

1993 ◽  
Vol 18 ◽  
pp. 208-210
Author(s):  
Hitoshi Shoji ◽  
Atau Mitani ◽  
Kohji Horita ◽  
Chester C. Langway
Keyword(s):  
Growth Rate ◽  
Plastic Deformation ◽  
Crystal Growth ◽  
Growth Rates ◽  
Strain Field ◽  
Crystal Size ◽  
Ice Core ◽  
Transformation Process ◽  
Ice Crystals ◽  
Air Bubbles

Continuous crystal-size measurements made on the G6 Antarctic ice core (100m deep) show enhanced growth rates above a depth of 30 m (Zone 1) and in the interval between 70 and 80 m (Zone 2). Crystal growth in Zone 1 most probably takes place by a process of sublimation and condensation. The higher growth rate in Zone 2 is most probably related to the pore close-off transformation process in which a non-uniform strain field is created to form air bubbles by plastic deformation and “cannibalization” of individual ice crystals.

scholarly journals Crystal growth rates in polar firn

1993 ◽  
Vol 18 ◽  
pp. 208-210 ◽  
Author(s):  
Hitoshi Shoji ◽  
Atau Mitani ◽  
Kohji Horita ◽  
Chester C. Langway
Keyword(s):  
Growth Rate ◽  
Plastic Deformation ◽  
Crystal Growth ◽  
Growth Rates ◽  
Strain Field ◽  
Crystal Size ◽  
Ice Core ◽  
Transformation Process ◽  
Ice Crystals ◽  
Air Bubbles

Continuous crystal-size measurements made on the G6 Antarctic ice core (100m deep) show enhanced growth rates above a depth of 30 m (Zone 1) and in the interval between 70 and 80 m (Zone 2). Crystal growth in Zone 1 most probably takes place by a process of sublimation and condensation. The higher growth rate in Zone 2 is most probably related to the pore close-off transformation process in which a non-uniform strain field is created to form air bubbles by plastic deformation and “cannibalization” of individual ice crystals.

scholarly journals The Internal Structure and Ice Crystallography of Seasonal Frost Mounds

1985 ◽  
Vol 31 (108) ◽  
pp. 157-162 ◽  
Author(s):  
W. H. Pollard ◽  
H. M. French
Keyword(s):  
Crystal Growth ◽  
Internal Structure ◽  
Active Layer ◽  
Growth Mechanism ◽  
Basal Plane ◽  
Ice Core ◽  
Ice Crystals ◽  
Rapid Freezing ◽  
Axis Direction ◽  
Primary Growth

AbstractThe crystal character of the ice core within frost blisters supports the hypothesis that groundwater injection into residual zones of the active layer followed by rapid freezing is the primary growth mechanism for these features. The ice core is characterized by an upper zone of relatively small randomly arranged equigranular ice crystals which change with increasing depth to columnar anhedral crystals, commonly exceeding 200 mm in length, and with crystal diameters ranging between 25 and 35 mm. Petrofabric analyses show that the c-axis orientations are normal to crystal elongations, with crystal growth along the basal plane in an a-axis direction. These observations eliminate ice segregation as a possible growth mechanism, thereby distinguishing seasonal frost mounds from palsas.

scholarly journals The Internal Structure and Ice Crystallography of Seasonal Frost Mounds

1985 ◽  
Vol 31 (108) ◽  
pp. 157-162 ◽  
Author(s):  
W. H. Pollard ◽  
H. M. French
Keyword(s):  
Crystal Growth ◽  
Internal Structure ◽  
Active Layer ◽  
Growth Mechanism ◽  
Basal Plane ◽  
Ice Core ◽  
Ice Crystals ◽  
Rapid Freezing ◽  
Axis Direction ◽  
Primary Growth

AbstractThe crystal character of the ice core within frost blisters supports the hypothesis that groundwater injection into residual zones of the active layer followed by rapid freezing is the primary growth mechanism for these features. The ice core is characterized by an upper zone of relatively small randomly arranged equigranular ice crystals which change with increasing depth to columnar anhedral crystals, commonly exceeding 200 mm in length, and with crystal diameters ranging between 25 and 35 mm. Petrofabric analyses show that thec-axis orientations are normal to crystal elongations, with crystal growth along the basal plane in ana-axis direction. These observations eliminate ice segregation as a possible growth mechanism, thereby distinguishing seasonal frost mounds from palsas.

scholarly journals MECHANISM OF BORAX CRYSTALLIZATION USING CONDUCTIVITY METHOD

2010 ◽  
Vol 8 (3) ◽  
pp. 327-330
Author(s):  
Suharso Suharso
Keyword(s):  
Growth Rate ◽  
Crystal Growth ◽  
Growth Mechanism ◽  
Spiral Growth ◽  
High Concentration ◽  
Conductivity Method ◽  
Principal Mechanism ◽  
Low Concentration ◽  
Kinetics Of ◽  
Kinetics Of Crystal Growth

The kinetics of crystal growth of borax has been studied by using conductivity method at temperature of 25 °C and at various relative supersaturations. It was found that the growth rate increases with increasing supersaturation. At low concentration, growth occurs via a spiral growth mechanism and at high concentration birth and spread is the principal mechanism operating.     Keywords: borax; growth rate; crystallization; conductivity method

scholarly journals Oxygen isotope fractionation during the freezing of sea water

2013 ◽  
Vol 59 (216) ◽  
pp. 697-710 ◽  
Author(s):  
Takenobu Toyota ◽  
Inga J. Smith ◽  
Alexander J. Gough ◽  
Patricia J. Langhorne ◽  
Gregory H. Leonard ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Growth Rate ◽  
Sea Ice ◽  
Oxygen Isotope ◽  
Laboratory Experiments ◽  
Isotope Fractionation ◽  
Sea Water ◽  
Mcmurdo Sound ◽  
Oxygen Isotope Fractionation ◽  
Ice Growth

AbstractThe dependence of oxygen isotope fractionation on ice growth rate during the freezing of sea water is investigated based on laboratory experiments and field observations in McMurdo Sound, Antarctica. The laboratory experiments were performed in a tank filled with sea water, with sea ice grown under calm conditions at various room temperatures ranging from −5°C to −20°C. In McMurdo Sound, the ice growth rate was monitored using thermistor probes for first-year landfast ice that grew to ∼2 m in thickness. Combining these datasets allows, for the first time, examination of fractionation at a wide range of growth rates from 0.8 × 10−7 to 9.3 × 10−7 m s−1. In the analysis a stagnant boundary-layer model is parameterized using these two independent datasets. As a result, the optimum values of equilibrium pure-ice fractionation factor and boundary-layer thickness are estimated. It is suggested that a regime shift may occur at a growth rate of ∼2.0 × 10−7 m s−1. A case study on sea ice in the Sea of Okhotsk, where the growth rate is modeled by coupling the thermodynamic properties of the sea ice with meteorological data, demonstrates the utility of the fitted models.

Montmorillonite Dendrites

1974 ◽  
Vol 32 ◽  
pp. 454-455
Author(s):  
Necip Güven ◽  
Rodney W. Pease
Keyword(s):  
Crystal Growth ◽  
Growth Mechanism ◽  
Growth Front ◽  
Morphological Features ◽  
Dendritic Crystal ◽  
Crystal Growth Mechanism

Morphological features of montmorillonite aggregates in a large number of samples suggest that they may be formed by a dendritic crystal growth mechanism (i.e., tree-like growth by branching of a growth front).

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