On a Reported New Form of Ice

Schiffer, J.; Hornig, D. F.

doi:10.1063/1.1701198

Cited by 10 publications

(16 citation statements)

References 4 publications

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“…(e) Infrared extinction spectra of the aerosol population at two different times of the experiment, as shown by the correspondingly labeled arrows on the timescale in the bottom left panel (black lines). Additionally shown in gray is a literature infrared spectrum of NaCl ∙ 2H 2 O in the O–H stretching and bending mode regimes, obtained by digitizing Figure from Schiffer and Hornig [].…”

Section: Resultsmentioning

confidence: 99%

“…They also underline, however, that this might simply be due to the different temperatures at which the Raman spectra were collected. Our recorded infrared spectra showed good agreement with those previously published for NaCl ∙ 2H 2 O [ Mutter et al ., ; Schiffer and Hornig , ], indicating that it is indeed the dihydrate that forms in the investigated temperature range. It is therefore reasonable to assume that also Wise et al .…”

Section: Introductionmentioning

confidence: 99%

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Heterogeneous ice nucleation ability of crystalline sodium chloride dihydrate particles

Wagner

Möhler

2013

JGR Atmospheres

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[1] The aerosol and cloud chamber AIDA (Aerosol Interactions and Dynamics in the Atmosphere) of the Karlsruhe Institute of Technology has been used to quantify the deposition mode ice nucleation ability of airborne crystalline sodium chloride dihydrate (NaCl • 2H 2 O) particles with median diameters between 0.06 and 1.1 mm. For this purpose, expansion cooling experiments with starting temperatures from 235 to 216 K were conducted. Recently, supermicron-sized NaCl • 2H 2 O particles deposited onto a surface have been observed to be ice-active in the deposition mode at temperatures below 238 K, requiring a median threshold ice saturation ratio of only 1.02 in the range from 238 to 221 K. In AIDA, heterogeneous ice nucleation by NaCl • 2H 2 O was first detected at a temperature of 227.1 K with a concomitant threshold ice saturation ratio of 1.25. Above that temperature, the crystallized salt particles underwent a deliquescence transition to form aqueous NaCl solution droplets upon increasing relative humidity. At nucleation temperatures below 225 K, the inferred threshold ice saturation ratios varied between 1.15 and 1.20. The number concentration of the nucleated ice crystals was related to the surface area of the seed aerosol particles to deduce the ice nucleation active surface site (INAS) density of the aerosol population as a function of the ice supersaturation. Maximum INAS densities of about 6 Á 10 10 m À2 at an ice saturation ratio of 1.20 were found for temperatures below 225 K. These INAS densities are similar to those recently derived for deposition mode ice nucleation on mineral dust particles.Citation: Wagner, R., and O. Mo¨hler (2013), Heterogeneous ice nucleation ability of crystalline sodium chloride dihydrate particles,

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Heterogeneous ice nucleation ability of crystalline sodium chloride dihydrate particles

Wagner

Möhler

2013

JGR Atmospheres

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“…(d) Infrared extinction spectra that were recorded at different time steps during the experiments, as indicated by the arrows and corresponding labels on the time axes of Figure c. The spectrum colored in green shown in Figure d was obtained by digitizing a previously published infrared spectrum of NaCl · 2H 2 O (Schiffer & Hornig, ). See text for details.…”

Section: Methodsmentioning

confidence: 99%

Heterogeneous Ice Nucleation Ability of NaCl and Sea Salt Aerosol Particles at Cirrus Temperatures

et al. 2018

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In situ measurements of the composition of heterogeneous cirrus ice cloud residuals have indicated a substantial contribution of sea salt in sampling regions above the ocean. We have investigated the heterogeneous ice nucleation ability of sodium chloride (NaCl) and sea salt aerosol (SSA) particles at cirrus cloud temperatures between 235 and 200 K in the Aerosol Interaction and Dynamics in the Atmosphere aerosol and cloud chamber. Effloresced NaCl particles were found to act as ice nucleating particles in the deposition nucleation mode at temperatures below about 225 K, with freezing onsets in terms of the ice saturation ratio, Sice, between 1.28 and 1.40. Above 225 K, the crystalline NaCl particles deliquesced and nucleated ice homogeneously. The heterogeneous ice nucleation efficiency was rather similar for the two crystalline forms of NaCl (anhydrous NaCl and NaCl dihydrate). Mixed‐phase (solid/liquid) SSA particles were found to act as ice nucleating particles in the immersion freezing mode at temperatures below about 220 K, with freezing onsets in terms of Sice between 1.24 and 1.42. Above 220 K, the SSA particles fully deliquesced and nucleated ice homogeneously. Ice nucleation active surface site densities of the SSA particles were found to be in the range between 1.0 · 1010 and 1.0 · 1011 m−2 at T < 220 K. These values are of the same order of magnitude as ice nucleation active surface site densities recently determined for desert dust, suggesting a potential contribution of SSA particles to low‐temperature heterogeneous ice nucleation in the atmosphere.

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“…9 and indeed bears the prominent signatures of sodium chloride dihydrate, as can be seen by the comparison with the reference spectra of NaCl · 2H 2 O in the regime of the O-H stretching (trace a1) and H-O-H bending mode (trace a2) that were obtained by digitising Fig. 1 from Schiffer and Hornig (1961). The second expansion cooling cycle in Exp.…”

Section: Detailed Analysis Of the Ternary Nacl/oa/h 2 O Ice Nucleatiomentioning

confidence: 97%

“…Similar to the IR spectroscopic study on the efflorescence of NaCl by Cziczo and Abbatt (2000), anhydrous crystals of sodium chloride have formed instead of NaCl · 2H 2 O that is the stable crystalline solid below the NaCl/NaCl · 2H 2 O peritectic temperature of 273.3 K . The latter species can be unambiguously identified by its prominent, highly structured infrared spectrum in the regime of the O-H stretching mode due to the hydration water (Schiffer and Hornig, 1961). We will discuss this issue in more detail in Sect.…”

Section: Ice Nucleation Studies In the Ternary Nacl/oa/h 2 O Systemmentioning

confidence: 99%

New cloud chamber experiments on the heterogeneous ice nucleation ability of oxalic acid in the immersion mode

et al. 2011

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Abstract. The heterogeneous ice nucleation ability of oxalic acid in the immersion mode has been investigated by controlled expansion cooling runs with airborne, ternary solution droplets composed of, (i), sodium chloride, oxalic acid, and water (NaCl/OA/H 2 O) and, (ii), sulphuric acid, oxalic acid, and water (H 2 SO 4 /OA/H 2 O). Polydisperse aerosol populations with median diameters ranging from 0.5-0.7 µm and varying solute concentrations were prepared. The expansion experiments were conducted in the AIDA aerosol and cloud chamber of the Karlsruhe Institute of Technology at initial temperatures of 244 and 235 K. In the ternary NaCl/OA/H 2 O system, solid inclusions of oxalic acid, presumably nucleated as oxalic acid dihydrate, were formed by temporarily exposing the ternary solution droplets to a relative humidity below the efflorescence point of NaCl. The matrix of the crystallised NaCl particulates triggered the precipitation of the organic crystals which later remained as solid inclusions in the solution droplets when the relative humidity was subsequently raised above the deliquescence point of NaCl. The embedded oxalic acid crystals reduced the critical ice saturation ratio required for the homogeneous freezing of pure NaCl/H 2 O solution droplets at a temperature of around 231 K from 1.38 to about 1.32. Aqueous solution droplets with OA inclusions larger than about 0.27 µm in diameter efficiently nucleated ice by condensation freezing when they were activated to micron-sized cloud droplets at 241 K, i.e., they froze well above the homogeneous freezing temperature of pure water droplets of about 237 K. Our results on the immersion freezing potential of oxalic acid corroborate the findings from a recent study with emulsified aqueous solutions containing crystalline oxalic acid. In those experiments, the crystallisation of oxalic acid diyhdrate was triggered by a preceding homogeneous freezing Correspondence to: R. Wagner (robert.wagner2@kit.edu) cycle with the emulsion samples. The expansion cooling cycles with ternary H 2 SO 4 /OA/H 2 O solution droplets were aimed to analyse whether those findings can be transferred to ice nucleation experiments with airborne oxalic acid containing aerosol particles. Under our experimental conditions, the efficiency by which the surface of homogeneously nucleated ice crystals triggered the precipitation of oxalic acid dihydrate was very low, i.e., less than one out of a hundred ice crystals that were formed by homogeneous freezing in a first expansion cooling cycle left behind an ice-active organic crystal that acted as immersion freezing nucleus in a second expansion cooling cycle.

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On a Reported New Form of Ice

Cited by 10 publications

References 4 publications

Heterogeneous ice nucleation ability of crystalline sodium chloride dihydrate particles

Heterogeneous ice nucleation ability of crystalline sodium chloride dihydrate particles

Heterogeneous Ice Nucleation Ability of NaCl and Sea Salt Aerosol Particles at Cirrus Temperatures

New cloud chamber experiments on the heterogeneous ice nucleation ability of oxalic acid in the immersion mode

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