Journal articles: 'Supercooled Bulk Water'

1

Pallares, G., M. El Mekki Azouzi, M. A. Gonzalez, et al. "Anomalies in bulk supercooled water at negative pressure." Proceedings of the National Academy of Sciences 111, no. 22 (2014): 7936–41. http://dx.doi.org/10.1073/pnas.1323366111.

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M, Rajasekaran, and K. Ganapathy Ayappa. "Influence of surface hydrophilicity and hydration on the rotational relaxation of supercooled water on graphene oxide surfaces." Physical Chemistry Chemical Physics 22, no. 28 (2020): 16080–95. http://dx.doi.org/10.1039/d0cp01515f.

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3

Kaneko, Toshihiro, Jaeil Bai, Takuma Akimoto, Joseph S. Francisco, Kenji Yasuoka, and Xiao Cheng Zeng. "Phase behaviors of deeply supercooled bilayer water unseen in bulk water." Proceedings of the National Academy of Sciences 115, no. 19 (2018): 4839–44. http://dx.doi.org/10.1073/pnas.1802342115.

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Akin to bulk water, water confined to an isolated nanoslit can show a wealth of new 2D phases of ice and amorphous ice, as well as unusual phase behavior. Indeed, 2D water phases, such as bilayer hexagonal ice and monolayer square ice, have been detected in the laboratory, confirming earlier computational predictions. Herein, we report theoretical evidence of a hitherto unreported state, namely, bilayer very low density amorphous ice (BL-VLDA), as well as evidence of a strong first-order transition between BL-VLDA and the BL amorphous ice (BL-A), and a weak first-order transition between BL-VLDA and the BL very low density liquid (BL-VLDL) water. The diffusivity of BL-VLDA is typically in the range of 10−9 cm2/s to 10−10 cm2/s. Similar to bulk (3D) water, 2D water can exhibit two forms of liquid in the deeply supercooled state. However, unlike supercooled bulk water, for which the two forms of liquid can coexist and merge into one at a critical point, the 2D BL-VLDL and BL high-density liquid (BL-HDL) phases are separated by the highly stable solid phase of BL-A whose melting line exhibits the isochore end point (IEP) near 220 K in the temperature−pressure diagram. Above the IEP temperature, BL-VLDL and BL-HDL are indistinguishable. At negative pressures, the metastable BL-VLDL exhibits a spatially and temporally heterogeneous structure induced by dynamic changes in the nanodomains, a feature much less pronounced in the BL-HDL.

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Botti, A., F. Bruni, M. A. Ricci, A. Pietropaolo, R. Senesi, and C. Andreani. "Structure and Single Proton Dynamics of Bulk Supercooled Water." Journal of Molecular Liquids 136, no. 3 (2007): 236–40. http://dx.doi.org/10.1016/j.molliq.2007.08.017.

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Lin, Chuanlong, Jesse S. Smith, Stanislav V. Sinogeikin, and Guoyin Shen. "Experimental evidence of low-density liquid water upon rapid decompression." Proceedings of the National Academy of Sciences 115, no. 9 (2018): 2010–15. http://dx.doi.org/10.1073/pnas.1716310115.

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Water is an extraordinary liquid, having a number of anomalous properties which become strongly enhanced in the supercooled region. Due to rapid crystallization of supercooled water, there exists a region that has been experimentally inaccessible for studying deeply supercooled bulk water. Using a rapid decompression technique integrated with in situ X-ray diffraction, we show that a high-pressure ice phase transforms to a low-density noncrystalline (LDN) form upon rapid release of pressure at temperatures of 140–165 K. The LDN subsequently crystallizes into ice-Ic through a diffusion-controlled process. Together with the change in crystallization rate with temperature, the experimental evidence indicates that the LDN is a low-density liquid (LDL). The measured X-ray diffraction data show that the LDL is tetrahedrally coordinated with the tetrahedral network fully developed and clearly linked to low-density amorphous ices. On the other hand, there is a distinct difference in structure between the LDL and supercooled water or liquid water in terms of the tetrahedral order parameter.

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Gasparotto, Piero, Martin Fitzner, Stephen James Cox, Gabriele Cesare Sosso, and Angelos Michaelides. "How do interfaces alter the dynamics of supercooled water?" Nanoscale 14, no. 11 (2022): 4254–62. http://dx.doi.org/10.1039/d2nr00387b.

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It is well known that the structure of liquid water in the proximity of an interface can deviate significantly from that of bulk water, while less clear is how an interface perturbs the dynamics of water molecules within the liquid.

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7

Peric, Ida, Dalibor Merunka, Barney L. Bales, and Miroslav Peric. "Rotation of Four Small Nitroxide Probes in Supercooled Bulk Water." Journal of Physical Chemistry Letters 4, no. 3 (2013): 508–13. http://dx.doi.org/10.1021/jz302107x.

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8

Hare, D. E., and C. M. Sorensen. "Raman spectroscopic study of bulk water supercooled to − 33 °C." Journal of Chemical Physics 93, no. 1 (1990): 25–33. http://dx.doi.org/10.1063/1.459599.

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9

Duki, Solomon F., and Mesfin Tsige. "Volume analysis of supercooled water under high pressure." MRS Advances 3, no. 41 (2018): 2467–78. http://dx.doi.org/10.1557/adv.2018.426.

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ABSTRACTMotivated by an experimental finding on the density of supercooled water at high pressure [O. Mishima, J. Chem. Phys. 133, 144503 (2010)] we performed atomistic molecular dynamics simulations study of bulk water in the isothermal-isobaric ensemble. Cooling and heating cycles at different isobars and isothermal compression at different temperatures are performed on the water sample with pressures that range from 0 to 1.0 GPa. The cooling simulations are done at temperatures that range from 40 K to 380 K using two different cooling rates, 10 K/ns and 10 K/5 ns. For the heating simulations we used the slowest heating rate (10 K/5 ns) by applying the same range of isobars. Our analysis of the variation of the volume of the bulk water sample with temperature at different pressures from both isobaric cooling/heating and isothermal compression cycles indicates a concave-downward curvature at high pressures that is consistent with the experiment for emulsified water. In particular, a strong concave down curvature is observed between the temperatures 180 K and 220 K. Below the glass transition temperature, which is around 180 K at 1GPa, the volume turns to concave upward curvature. No crystallization of the supercooled liquid state was observed below 180 K even after running the system for an additional microsecond.

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10

Kim, Kyung Hwan, Katrin Amann-Winkel, Nicolas Giovambattista, et al. "Experimental observation of the liquid-liquid transition in bulk supercooled water under pressure." Science 370, no. 6519 (2020): 978–82. http://dx.doi.org/10.1126/science.abb9385.

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We prepared bulk samples of supercooled liquid water under pressure by isochoric heating of high-density amorphous ice to temperatures of 205 ± 10 kelvin, using an infrared femtosecond laser. Because the sample density is preserved during the ultrafast heating, we could estimate an initial internal pressure of 2.5 to 3.5 kilobar in the high-density liquid phase. After heating, the sample expanded rapidly, and we captured the resulting decompression process with femtosecond x-ray laser pulses at different pump-probe delay times. A discontinuous structural change occurred in which low-density liquid domains appeared and grew on time scales between 20 nanoseconds to 3 microseconds, whereas crystallization occurs on time scales of 3 to 50 microseconds. The dynamics of the two processes being separated by more than one order of magnitude provides support for a liquid-liquid transition in bulk supercooled water.

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11

Mallamace, Francesco, Giuseppe Mensitieri, Domenico Mallamace, Martina Salzano de Luna, and Sow-Hsin Chen. "Some Aspects of the Liquid Water Thermodynamic Behavior: From The Stable to the Deep Supercooled Regime." International Journal of Molecular Sciences 21, no. 19 (2020): 7269. http://dx.doi.org/10.3390/ijms21197269.

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Liquid water is considered to be a peculiar example of glass forming materials because of the possibility of giving rise to amorphous phases with different densities and of the thermodynamic anomalies that characterize its supercooled liquid phase. In the present work, literature data on the density of bulk liquid water are analyzed in a wide temperature-pressure range, also including the glass phases. A careful data analysis, which was performed on different density isobars, made in terms of thermodynamic response functions, like the thermal expansion αP and the specific heat differences CP−CV, proves, exclusively from the experimental data, the thermodynamic consistence of the liquid-liquid transition hypothesis. The study confirms that supercooled bulk water is a mixture of two liquid “phases”, namely the high density (HDL) and the low density (LDL) liquids that characterize different regions of the water phase diagram. Furthermore, the CP−CV isobars behaviors clearly support the existence of both a liquid–liquid transition and of a liquid–liquid critical point.

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12

Li, Yuqing, Zehua Han, Changli Ma, et al. "Structure and dynamics of supercooled water in the hydration layer of poly(ethylene glycol)." Structural Dynamics 9, no. 5 (2022): 054901. http://dx.doi.org/10.1063/4.0000158.

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The statics and dynamics of supercooled water in the hydration layer of poly(ethylene glycol) (PEG) were studied by a combination of quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations. Two samples, that is, hydrogenated PEG/deuterated water (h-PEG/D2O) and fully deuterated PEG/hydrogenated water (d-PEG/H2O) with the same molar ratio of ethylene glycol (EG) monomer to water, 1:1, are compared. The QENS data of h-PEG/D2O show the dynamics of PEG, and that of d-PEG/H2O reveals the motion of water. The temperature-dependent elastic scattering intensity of both samples has shown transitions at supercooled temperature, and these transition temperatures depend on the energy resolution of the instruments. Therefore, neither one is a phase transition, but undergoes dynamic process. The dynamic of water can be described as an Arrhenius to super-Arrhenius transition, and it reveals the hydrogen bonding network relaxation of hydration water around PEG at supercooled temperature. Since the PEG-water hydrogen bond structural relaxation time from MD is in good agreement with the average relaxation time from QENS (d-PEG/H2O), MD may further reveal the atomic pictures of the supercooled hydration water. It shows that hydration water molecules form a series of pools around the hydrophilic oxygen atom of PEG. At supercooled temperature, they have a more bond ordered structure than bulk water, proceed a trapping sites diffusion on the PEG surface, and facilitate the structural relaxation of PEG backbone.

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13

Gallo, P., M. Rovere, and S. H. Chen. "Dynamic Crossover in Supercooled Confined Water: Understanding Bulk Properties through Confinement." Journal of Physical Chemistry Letters 1, no. 4 (2010): 729–33. http://dx.doi.org/10.1021/jz9003125.

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14

Swenson, Jan. "Possible relations between supercooled and glassy confined water and amorphous bulk ice." Physical Chemistry Chemical Physics 20, no. 48 (2018): 30095–103. http://dx.doi.org/10.1039/c8cp05688a.

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15

Zhao, Yan Chun, Rui Peng Mao, Wen Long Ma, Cong Yu Xu, and Sheng Zhong Kou. "Microstructure and Corrosion Behavior of Ti-Ni Based Bulk Metallic Glass Composites." Materials Science Forum 898 (June 2017): 666–71. http://dx.doi.org/10.4028/www.scientific.net/msf.898.666.

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In this study, (Ti0.5Ni0.5)80Cu20 metallic glass composites sample with 3mm diameter were prepared by levitation suspend melting-water cooled Cu mold process. Microstructure and thermodynamic behavior of the alloy were characterized by XRD, OM and DSC. the potention dynamic polarization curves in artificial seawater were tested by electrochemical workstation in a three-electrode system. The results showed that the as-cast microstructure of the alloy is consist of supercooled austenite phase, thermally-induced martensite phase and amorphous phase. Due to cooling rate, random dense pile of amorphous structure formed in surface of the alloy and supercooled austenite phase formed in interior. Besides, the alloy also presented excellent corrosion-resistance in artificial seawater for its higher corrosion potential (Ecorr) and polarization resistance (Rp), lower corrosion current density (Icorr) compared with Ti-6Al-4V(TC4) alloy.

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16

Banerjee, D., S. N. Bhat, S. V. Bhat, and D. Leporini. "ESR evidence for 2 coexisting liquid phases in deeply supercooled bulk water." Proceedings of the National Academy of Sciences 106, no. 28 (2009): 11448–53. http://dx.doi.org/10.1073/pnas.0900734106.

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17

Neuefeind, J., C. J. Benmore, J. K. R. Weber, and D. Paschek. "More accurate X-ray scattering data of deeply supercooled bulk liquid water." Molecular Physics 109, no. 2 (2011): 279–88. http://dx.doi.org/10.1080/00268976.2010.520040.

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18

Bin, Maddalena, Rafat Yousif, Sharon Berkowicz, Sudipta Das, Daniel Schlesinger, and Fivos Perakis. "Wide-angle X-ray scattering and molecular dynamics simulations of supercooled protein hydration water." Physical Chemistry Chemical Physics 23, no. 34 (2021): 18308–13. http://dx.doi.org/10.1039/d1cp02126e.

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We investigate hydrated proteins by decomposing the water and protein components and we observe that the protein signal is nearly temperature independent, whereas that of hydration water exhibits a trend similar to bulk water.

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19

Fardis, Michael, Marina Karagianni, Lydia Gkoura, and George Papavassiliou. "Self-Diffusion in Confined Water: A Comparison between the Dynamics of Supercooled Water in Hydrophobic Carbon Nanotubes and Hydrophilic Porous Silica." International Journal of Molecular Sciences 23, no. 22 (2022): 14432. http://dx.doi.org/10.3390/ijms232214432.

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Confined liquids are model systems for the study of the metastable supercooled state, especially for bulk water, in which the onset of crystallization below 230 K hinders the application of experimental techniques. Nevertheless, in addition to suppressing crystallization, confinement at the nanoscale drastically alters the properties of water. Evidently, the behavior of confined water depends critically on the nature of the confining environment and the interactions of confined water molecules with the confining matrix. A comparative study of the dynamics of water under hydrophobic and hydrophilic confinement could therefore help to clarify the underlying interactions. As we demonstrate in this work using a few representative results from the relevant literature, the accurate assessment of the translational mobility of water molecules, especially in the supercooled state, can unmistakably distinguish between the hydrophilic and hydrophobic nature of the confining environments. Among the numerous experimental methods currently available, we selected nuclear magnetic resonance (NMR) in a field gradient, which directly measures the macroscopic translational self-diffusion coefficient, and quasi-elastic neutron scattering (QENS), which can determine the microscopic translational dynamics of the water molecules. Dielectric relaxation, which probes the re-orientational degrees of freedom, are also discussed.

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20

GONG, PAN, KEFU YAO, and HONGYU DING. "CENTIMETER-SIZED Ti-BASED QUATERNARY BULK METALLIC GLASS PREPARED BY WATER QUENCHING." International Journal of Modern Physics B 27, no. 18 (2013): 1350087. http://dx.doi.org/10.1142/s0217979213500872.

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Till now, the developed centimeter-sized Ti-based bulk metallic glasses (BMGs) always consist of at least five elements. We report that Ti 41 Zr 25 Be 28 Fe 6 quaternary glassy alloy can be made up to 10 mm in diameter by water quenching, while only ϕ 8 mm fully glassy rod can be obtained by copper mould suction casting. This alloy possesses fewer constituent elements, wider supercooled liquid region and higher specific strength than other developed centimeter-sized Ti-based BMGs and has wide prospect for practical application. Our results also indicate that for Ti 41 Zr 25 Be 28 Fe 6 alloy which possesses relatively strong glass-forming ability, reducing the heterogeneous impurities in the melt is more effective to obtain fully glassy samples than increasing the cooling rate merely.

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21

Hare, D. E., and C. M. Sorensen. "The density of supercooled water. II. Bulk samples cooled to the homogeneous nucleation limit." Journal of Chemical Physics 87, no. 8 (1987): 4840–45. http://dx.doi.org/10.1063/1.453710.

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22

Botti, A., F. Bruni, A. Isopo, M. A. Ricci, and A. K. Soper. "Experimental determination of the site–site radial distribution functions of supercooled ultrapure bulk water." Journal of Chemical Physics 117, no. 13 (2002): 6196–99. http://dx.doi.org/10.1063/1.1503337.

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23

Гурулев, А. А., та А. О. Орлов. "Проявление линии Видома при микроволновых измерениях увлажненных перекисью водорода сорбентов". Письма в журнал технической физики 48, № 2 (2022): 41. http://dx.doi.org/10.21883/pjtf.2022.02.51921.18995.

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For deeply supercooled bulk water, anomalies of thermodynamic values are known near the Widom line, the locus of increased fluctuations of entropy and density. In this work, we measured the reflected power of microwave radiation at a frequency of 18 GHz from a silicate sorbent sample moistened with a hydrogen peroxide solution. In the experiment, we observed variations in the recorded reflected radiation power in the range –46 – –47 °С, determined by structural changes in the liquid. Thus, it is shown that fluctuations of water parameters near the Widom line are manifested in changes not only in thermodynamic, but also in electrophysical quantities.

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24

Haji-Akbari, Amir, and Pablo G. Debenedetti. "Computational investigation of surface freezing in a molecular model of water." Proceedings of the National Academy of Sciences 114, no. 13 (2017): 3316–21. http://dx.doi.org/10.1073/pnas.1620999114.

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Water freezes in a wide variety of low-temperature environments, from meteors and atmospheric clouds to soil and biological cells. In nature, ice usually nucleates at or near interfaces, because homogenous nucleation in the bulk can only be observed at deep supercoolings. Although the effect of proximal surfaces on freezing has been extensively studied, major gaps in understanding remain regarding freezing near vapor–liquid interfaces, with earlier experimental studies being mostly inconclusive. The question of how a vapor–liquid interface affects freezing in its vicinity is therefore still a major open question in ice physics. Here, we address this question computationally by using the forward-flux sampling algorithm to compute the nucleation rate in a freestanding nanofilm of supercooled water. We use the TIP4P/ice force field, one of the best existing molecular models of water, and observe that the nucleation rate in the film increases by seven orders of magnitude with respect to bulk at the same temperature. By analyzing the nucleation pathway, we conclude that freezing in the film initiates not at the surface, but within an interior region where the formation of double-diamond cages (DDCs) is favored in comparison with the bulk. This, in turn, facilitates freezing by favoring the formation of nuclei rich in cubic ice, which, as demonstrated by us earlier, are more likely to grow and overcome the nucleation barrier. The films considered here are ultrathin because their interior regions are not truly bulk-like, due to their subtle structural differences with the bulk.

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25

García-García, F., and Roland List. "Laboratory Measurements and Parameterizations of Supercooled Water Skin Temperatures and Bulk Properties of Gyrating Hailstones." Journal of the Atmospheric Sciences 49, no. 22 (1992): 2058–73. http://dx.doi.org/10.1175/1520-0469(1992)049<2058:lmapos>2.0.co;2.

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26

Malik, Sheeba, Smarajit Karmakar, and Ananya Debnath. "Relaxation time scales of interfacial water upon fluid to ripple to gel phase transitions of bilayers." Journal of Chemical Physics 158, no. 11 (2023): 114503. http://dx.doi.org/10.1063/5.0138681.

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The slow relaxation of interface water (IW) across three primary phases of membranes is relevant to understand the influence of IW on membrane functions at supercooled conditions. To this objective, a total of [Formula: see text]s all-atom molecular dynamics simulations of 1,2-dimyristoyl-sn-glycerol-3-phosphocholine lipid membranes are carried out. A supercooling-driven drastic slow-down in heterogeneity time scales of the IW is found at the fluid to the ripple to the gel phase transitions of the membranes. At both fluid-to-ripple-to-gel phase transitions, the IW undergoes two dynamic crossovers in Arrhenius behavior with the highest activation energy at the gel phase due to the highest number of hydrogen bonds. Interestingly, the Stokes–Einstein (SE) relation is conserved for the IW near all three phases of the membranes for the time scales derived from the diffusion exponents and the non-Gaussian parameters. However, the SE relation breaks for the time scale obtained from the self-intermediate scattering functions. The behavioral difference in different time scales is universal and found to be an intrinsic property of glass. The first dynamical transition in the α relaxation time of the IW is associated with an increase in the Gibbs energy of activation of hydrogen bond breaking with locally distorted tetrahedral structures, unlike the bulk water. Thus, our analyses unveil the nature of the relaxation time scales of the IW across membrane phase transitions in comparison with the bulk water. The results will be useful to understand the activities and survival of complex biomembranes under supercooled conditions in the future.

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27

Seo, Eun-Kyoung, and Michael I. Biggerstaff. "Impact of Cloud Model Microphysics on Passive Microwave Retrievals of Cloud Properties. Part II: Uncertainty in Rain, Hydrometeor Structure, and Latent Heating Retrievals." Journal of Applied Meteorology and Climatology 45, no. 7 (2006): 955–72. http://dx.doi.org/10.1175/jam2374.1.

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Abstract The impact of model microphysics on the retrieval of cloud properties based on passive microwave observations was examined using a three-dimensional, nonhydrostatic, adaptive-grid cloud model to simulate a mesoscale convective system over ocean. Two microphysical schemes, based on similar bulk two-class liquid and three-class ice parameterizations, were used to simulate storms with differing amounts of supercooled cloud water typical of both the tropical oceanic environment, in which there is little supercooled cloud water, and midlatitude continental environments in which supercooled cloud water is more plentiful. For convective surface-level rain rates, the uncertainty varied between 20% and 60% depending on which combination of passive and active microwave observations was used in the retrieval. The uncertainty in surface rain rate did not depend on the microphysical scheme or the parameter settings except for retrievals over stratiform regions based on 85-GHz brightness temperatures TB alone or 85-GHz TB and radar reflectivity combined. In contrast, systematic differences in the treatment of the production of cloud water, cloud ice, and snow between the parameterization schemes coupled with the low correlation between those properties and the passive microwave TB examined here led to significant differences in the uncertainty in retrievals of those cloud properties and latent heating. The variability in uncertainty of hydrometeor structure and latent heating associated with the different microphysical parameterizations exceeded the inherent variability in TB–cloud property relations. This was true at the finescales of the cloud model as well as at scales consistent with satellite footprints in which the inherent variability in TB–cloud property relations are reduced by area averaging.

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Saleeby, Stephen M., and William R. Cotton. "A Binned Approach to Cloud-Droplet Riming Implemented in a Bulk Microphysics Model." Journal of Applied Meteorology and Climatology 47, no. 2 (2008): 694–703. http://dx.doi.org/10.1175/2007jamc1664.1.

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Abstract This paper presents the development and application of a binned approach to cloud-droplet riming within a bulk microphysics model. This approach provides a more realistic representation of collision–coalescence that occurs between ice and cloud particles of various sizes. The binned approach allows the application of specific collection efficiencies, within the stochastic collection equation, for individual size bins of droplets and ice particles; this is in sharp contrast to the bulk approach that uses a single collection efficiency to describe the growth of a distribution of an ice species by collecting cloud droplets. Simulations of a winter orographic cloud event reveal a reduction in riming when using the binned riming approach and, subsequently, larger amounts of supercooled liquid water within the orographic cloud.

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29

BASKOUTAS, S., P. LEMIS-PETROPOULOS, V. KAPAKLIS, Y. KOVEOS, and C. POLITIS. "NANOSTRUCTURED AND BULK AMORPHOUS Zr-BASED ALLOYS PREPARED BY MECHANICAL ALLOYING AND ARC MELTING." International Journal of Modern Physics B 17, no. 10 (2003): 2035–44. http://dx.doi.org/10.1142/s021797920301817x.

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We have produced powders of nanostructured and amorphous alloys as well as bulk amorphous alloys with composition Zr 64 Cu 18 Ni 10 Al 8 by mechanical alloying and by quenching arc melted melts in water cooled cooper dies, respectively. The alloys were investigated by X-ray diffraction as well as by thermal analysis in order to determine the structure and thermal properties. The mechanical alloyed amorphous powders and bulk amorphous cylinders show the same thermal and X-ray characteristics. For the amorphous powders, we find that the glass transition temperature Tg is 657 K and the crystallization temperature Tx is 752 K. For bulk amorphous alloys with the same composition prepard by arc melting and liquid quenching Tgis 655 K and the Tx is 725 K. Moreover for the bulk amorphous alloys the supercooled liquid region Δ Txg is 70 K, the reduced glass transition temperature tg is 0.557, the Lu–Liu parameter γ which represents the glass forming ability for bulk metallic glasses is 0.396 and experimentally the critical cooling rate Rc takes the value 7 K s -1.

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30

Gurulev A. A. and Orlov A. O. "Manifestation of the Widom line in microwave measurements of sorbents moistened with hydrogen peroxide." Technical Physics Letters 48, no. 1 (2022): 81. http://dx.doi.org/10.21883/tpl.2022.01.52478.18995.

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For deeply supercooled bulk water, known are anomalies of thermodynamic quantities near the Widom line, the locus of increased fluctuations of entropy and density. In this work, we measured the reflected power of microwave radiation at the frequency of 18 GHz from a silicate sorbent sample moistened with a hydrogen peroxide solution. In the experiment, we observed variations in the recorded reflected radiation power in the range of -46 to -47oC determined by structural changes in the liquid. Thus, it is shown that fluctuations of water parameters near the Widom line manifest themselves in changes not only in thermodynamic, but also in electrophysical quantities. Keywords: Widom line, second critical point, nanoporous materials, hydrogen peroxide, microwaves.

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31

Wada, Takeshi, Makoto Kinaka, and Akihisa Inoue. "Effect of volume fraction and geometry of pores on mechanical properties of porous bulk glassy Pd42.5Cu30Ni7.5P20 alloys." Journal of Materials Research 21, no. 4 (2006): 1041–47. http://dx.doi.org/10.1557/jmr.2006.0127.

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Porous Pd42.5Cu30Ni7.5P20 bulk glassy alloy rods with porosities up to 71% were successfully prepared by water quenching in a 15 MPa hydrogen atmosphere, followed by heat treatment in a supercooled liquid state. Pores with sizes up to 80 μm were homogeneously distributed over the whole cross-sectional area. Under compressive deformation, the porous alloys with porosities exceeding 41% did not show macroscopic fracture in a wide compressive strain range up to 0.6. Mechanical tests with porous alloy rods whose pores are anisotropically oriented indicate that the plasticity of the porous alloy is strongly affected by stress concentration factor.

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32

Peric, Ida, Dalibor Merunka, Barney L. Bales, and Miroslav Peric. "Hydrodynamic and Nonhydrodynamic Contributions to the Bimolecular Collision Rates of Solute Molecules in Supercooled Bulk Water." Journal of Physical Chemistry B 118, no. 25 (2014): 7128–35. http://dx.doi.org/10.1021/jp501330x.

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33

Roh, Woosub, Masaki Satoh, Tempei Hashino, Hajime Okamoto, and Tatsuya Seiki. "Evaluations of the Thermodynamic Phases of Clouds in a Cloud-System-Resolving Model Using CALIPSO and a Satellite Simulator over the Southern Ocean." Journal of the Atmospheric Sciences 77, no. 11 (2020): 3781–801. http://dx.doi.org/10.1175/jas-d-19-0273.1.

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AbstractA new evaluation method for the thermodynamic phases of clouds in cloud-system-resolving models is presented using CALIPSO observations and a satellite simulator. This method determines the thermodynamic phases using the depolarization ratio and a cloud extinction proxy. For the evaluation, we introduced empirical parameterization of the depolarization ratio of ice and water clouds using temperatures of a reanalysis dataset and total attenuated backscatters of CALIPSO. We evaluated the mixed-phase clouds simulated in a cloud-system-resolving model over the Southern Ocean using single-moment and double-moment bulk cloud microphysics schemes, referred to as NSW6 and NDW6, respectively. The NDW6 simulations reproduce supercooled water clouds near the boundary layer that are consistent with the observations. Conversely, the NSW6 simulations failed to reproduce such supercooled water clouds. Consistencies between the cloud classes diagnosed by the evaluation method and the simulated hydrometeor categories were examined. NDW6 shows diagnosed water and ice classes that are consistent with the simulated categories, whereas the ice category simulated with NSW6 is diagnosed as liquid water by the present method due to the large extinction from the ice cloud layers. Additional analyses indicated that ice clouds with a small effective radius and large ice water content in NSW6 lead to erroneous values for the fraction of the diagnosed liquid water. It is shown that the uncertainty in the cloud classification method depends on the details of the cloud microphysics schemes. It is important to understand the causes of inconsistencies in order to properly understand the cloud classification applied to model evaluations as well as retrievals.

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Seiki, Tatsuya, and Woosub Roh. "Improvements in Supercooled Liquid Water Simulations of Low-Level Mixed-Phase Clouds over the Southern Ocean Using a Single-Column Model." Journal of the Atmospheric Sciences 77, no. 11 (2020): 3803–19. http://dx.doi.org/10.1175/jas-d-19-0266.1.

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AbstractA high-resolution global atmospheric model, the nonhydrostatic icosahedral atmospheric model (NICAM), exhibited underestimation biases in low-level mixed-phase clouds in the midlatitudes and polar regions. The ice-cloud microphysics used in a single-moment bulk cloud microphysics scheme (NSW6) was evaluated and improved using a single-column model by reference to a double-moment bulk cloud microphysics scheme (NDW6). Budget analysis indicated that excessive action of the Bergeron–Findeisen and riming processes crucially reduced supercooled liquid water. In addition, the rapid production of rain directly reduced cloud water and indirectly reduced cloud water through the production of snow and graupel by riming. These biases in growth rates were found to originate from the number concentration diagnosis used in NSW6. The diagnosis based on the midlatitude cloud systems assumption was completely different from the one for low-level mixed-phase clouds. To alleviate underestimation biases, rain production, heterogeneous ice nucleation, vapor deposition by snow and graupel, and riming processes were revised. The sequential revisions of cloud microphysics alleviated the underestimation biases step by step without parameter tuning. The lifetime of cloud layers simulated by NSW6 was reasonably prolonged.

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Netz, Paulo A. "Molecular dynamics simulations of structural and dynamical aspects of DNA hydration water." Journal of Physics: Condensed Matter 34, no. 16 (2022): 164002. http://dx.doi.org/10.1088/1361-648x/ac5198.

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Abstract Water is a remarkable liquid, both because of it is intriguing but also because of its importance. Water plays a key role on the structure and function of biological molecules, but on the other hand also the structure and dynamics of water are deeply influenced by its interactions with biological molecules, specially at low temperatures, where water’s anomalies are enhanced. Here we present extensive molecular dynamics simulations of water hydrating a oligonucleotide down to very low temperatures (supercooled water), comparing four water models and analyzing the water structure and dynamics in different domains: water in the minor groove, water in the major groove and bulk water. We found that the water in the grooves is slowed down by the interactions with the nucleic acid and a hints of a dynamic transition regarding translational and orientational dynamics were found, specially for the water models TIP4P/2005 and TIP4P-Ew, which also showed the closest agreement with available experimental data. The behavior of water in such extreme conditions is relevant for the study of cryopreservation of biological tissues.

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Kuhn, T., M. E. Earle, A. F. Khalizov, and J. J. Sloan. "Size dependence of volume and surface nucleation rates for homogeneous freezing of supercooled water droplets." Atmospheric Chemistry and Physics Discussions 9, no. 5 (2009): 22929–53. http://dx.doi.org/10.5194/acpd-9-22929-2009.

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Abstract. We investigated the relative roles of volume and surface nucleation in the freezing of water droplets. Nucleation experiments were carried out in a cryogenic laminar aerosol flow tube using supercooled liquid water aerosols with radii between about 1 and 3 μ m. Temperature- and size-dependent values of volume- and surface-based homogeneous nucleation rate between 234.8 and 236.2 K are derived with help of a microphysical model from aerosol compositions and size distributions based on infrared extinction measurements in the aerosol flow tube. The results show that the contribution from nucleation at the droplet surface increases with decreasing droplet radius and dominates over nucleation in the bulk droplet volume for droplets with radii smaller than approximately 5 μm. This is interpreted in terms of a lowered free energy of ice germ formation in the surface-based process and has implications for the parameterization of homogeneous ice nucleation in numerical models.

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Kuhn, T., M. E. Earle, A. F. Khalizov, and J. J. Sloan. "Size dependence of volume and surface nucleation rates for homogeneous freezing of supercooled water droplets." Atmospheric Chemistry and Physics 11, no. 6 (2011): 2853–61. http://dx.doi.org/10.5194/acp-11-2853-2011.

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Abstract. The relative roles of volume and surface nucleation were investigated for the homogeneous freezing of pure water droplets. Experiments were carried out in a cryogenic laminar aerosol flow tube using supercooled water aerosols with maximum volume densities at radii between 1 and 3 μm. Temperature- and size-dependent values of volume- and surface-based homogeneous nucleation rates between 234.8 and 236.2 K were derived using a microphysical model and aerosol phase compositions and size distributions determined from infrared extinction measurements in the flow tube. The results show that the contribution from nucleation at the droplet surface increases with decreasing droplet radius and dominates over nucleation in the bulk droplet volume for droplets with radii smaller than approximately 5 μm. This is interpreted in terms of a lowered free energy of ice germ formation in the surface-based process. The implications of surface nucleation for the parameterization of homogeneous ice nucleation in numerical models are considered.

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Abel, S. J., R. J. Cotton, P. A. Barrett, and A. K. Vance. "A comparison of ice water content measurement techniques on the FAAM BAe-146 aircraft." Atmospheric Measurement Techniques 7, no. 9 (2014): 3007–22. http://dx.doi.org/10.5194/amt-7-3007-2014.

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Abstract. This paper presents a comparison of ice water content (qi) data from a variety of measurement techniques on the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft. Data are presented from a range of cloud types measured during the PIKNMIX field experiment that include mixed-phase stratocumulus, cumulus congestus and cirrus clouds. These measurements cover a broad range of conditions in which atmospheric ice particles are found in nature, such as the low-ice-water-content environments typically found in midlatitude cirrus and the environments with much higher ice water content often observed in cold convective clouds. The techniques include bulk measurements from (i) a Nevzorov hot-wire probe, (ii) the difference between the measured total water content (condensed plus vapour) and the water vapour content of the atmosphere and (iii) a counterflow virtual impactor (CVI) (only for cirrus measurements). We also estimate the qi from integration of the measured particle size distribution (PSD) with assumptions on how the density of ice particles varies as a function of size. The results show that the only bulk ice water content technique capable of measuring high qi values (several g m−3) was the method of total water content minus water vapour. For low ice water contents we develop a new parametrisation of the Nevzorov baseline drift that enables the probe to be sensitive to qi ± 0.002 g m−3. In cirrus clouds the agreement between the Nevzorov and other bulk measurements was typically better than a factor of 2 for the CVI (qi > 0.008 g m−3) and the method of total water content minus water vapour (qi > 0.02 g m−3). Good agreement with the bulk measurements for all cases could be obtained with the estimate from the PSD provided that appropriate a priori assumptions on the mass–dimension relationship were made. This is problematic in the convective clouds sampled because pristine ice particles, heavily rimed particles and supercooled liquid drops were all present. In a cirrus case, we show that using a temperature-dependent mass–dimension relation was required to match the bulk measurement of qi.

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Abel, S. J., R. J. Cotton, P. A. Barrett, and A. K. Vance. "A comparison of ice water content measurement techniques on the FAAM BAe-146 aircraft." Atmospheric Measurement Techniques Discussions 7, no. 5 (2014): 4815–57. http://dx.doi.org/10.5194/amtd-7-4815-2014.

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Abstract. This paper presents a comparison of ice water content (qi) data from a variety of measurement techniques on the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 research aircraft. Data are presented from a range of cloud types measured during the PIKNMIX field experiment that include mixed phase stratocumulus, cumulus congestus and cirrus clouds. These measurements cover a broad range of conditions in which atmospheric ice particles are found in nature, such as the low ice water content environments typically found in mid-latitude cirrus and the much higher ice water content environments often observed in cold convective clouds. The techniques include bulk measurements from (i) a Nevzorov hot-wire probe (ii) the difference between the measured total water content (condensed plus vapour) and the water vapour content of the atmosphere and (iii) a Counterflow Virtual Impactor (CVI) (only for cirrus measurements). We also estimate the qi from integration of the measured particle size distribution (PSD) with assumptions on how the density of ice particles varies as a function of size. The results show that the only bulk ice water content technique capable of measuring high qi values (several g kg−1) was the total water content minus water vapour method. For low ice water contents we develop a new parametrization of the Nevzorov base-line drift that enables the probe to be sensitive to qi ± 0.002 g m−3. In cirrus clouds the agreement between the Nevzorov and other bulk measurements was typically better than a factor of two for the CVI (qi 0.01 g kg−1) and the total water content minus water vapour method (qi > 0.03 g kg−1). Good agreement with the bulk measurements for all cases could be obtained with the estimate from the PSD provided that appropriate a-priori assumptions on the mass–dimension relationship were made. This is problematic in the convective clouds sampled because pristine ice particles, heavily rimed particles and supercooled liquid drops were all present. In a cirrus case we show that using a temperature dependent mass–dimension relation was required to match the bulk measurement of qi.

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Biggerstaff, Michael I., Eun-Kyoung Seo, Svetla M. Hristova-Veleva, and Kwang-Yul Kim. "Impact of Cloud Model Microphysics on Passive Microwave Retrievals of Cloud Properties. Part I: Model Comparison Using EOF Analyses." Journal of Applied Meteorology and Climatology 45, no. 7 (2006): 930–54. http://dx.doi.org/10.1175/jam2372.1.

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Abstract The impact of model microphysics on the relationships among hydrometeor profiles, latent heating, and derived satellite microwave brightness temperatures TB have been examined using a nonhydrostatic, adaptive-grid cloud model to simulate a mesoscale convective system over water. Two microphysical schemes (each employing three-ice bulk parameterizations) were tested for two different assumptions in the number of ice crystals assumed to be activated at 0°C to produce simulations with differing amounts of supercooled cloud water. The model output was examined using empirical orthogonal function (EOF) analysis, which provided a quantitative framework in which to compare the simulations. Differences in the structure of the vertical anomaly patterns were related to physical processes and attributed to different approaches in cloud microphysical parameterizations in the two schemes. Correlations between the first EOF coefficients of cloud properties and TB at frequencies associated with the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) showed additional differences between the two parameterization schemes that affected the relationship between hydrometeors and TB. Classified in terms of TB, the microphysical schemes produced significantly different mean vertical profiles of cloud water, cloud ice, snow, vertical velocity, and latent heating. The impact of supercooled cloud water on the 85-GHz TB led to a 15% variation in mean convective rain mass at the surface. The variability in mean profiles produced by the four simulations indicates that the retrievals of cloud properties, especially latent heating, based on TMI frequencies are dependent on the particular microphysical parameterizations used to construct the retrieval database.

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Sugimoto, Hiroyuki, Kozo Kanayama, and Misato Norimoto. "Dielectric relaxation of water adsorbed on wood and charcoal." Holzforschung 61, no. 1 (2007): 89–94. http://dx.doi.org/10.1515/hf.2007.014.

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Abstract The dielectric relaxation due to motions of water molecules adsorbed on wood treated at various temperatures up to 550°C was investigated based on the relationships between activation enthalpy (ΔH) and entropy (ΔS) in relaxation. The relationships indicated two straight lines with different slopes, depending on the treatment temperature. Given the same ΔS, ΔH values for water molecules adsorbed on wood treated at temperatures below 400°C were greater than for those treated above 450°C. It was considered that before heat treatment, water molecules were adsorbed mainly on hydroxyl groups by strong hydrogen bonds and formed ice-like structures. On the other hand, hydroxyl groups were not detected in wood after heat treatments above 400°C. We assume that water molecules are condensed in nanometer-scale micropores that are formed during the carbonization of wood. The relationship between ΔH and ΔS for the motion of water adsorbed on wood treated above 450°C was similar to the value extrapolated from that for bulk water at temperatures below 0°C. We suggest that water molecules are adsorbed on charcoal in a supercooled state.

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42

Torres, James R., Zachary N. Buck, Helmut Kaiser, et al. "Study of the water dynamics near hydrophilic, nanostructured CuO surfaces by quasielastic and inelastic neutron scattering." AIP Advances 12, no. 6 (2022): 065124. http://dx.doi.org/10.1063/5.0096948.

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We have used quasielastic and inelastic neutron scattering to investigate the structure, dynamics, and phase transitions of water interacting with superhydrophilic CuO surfaces that not only possess a strong affinity for water but also a “grass-like” topography that is rough on both micro- and nanoscales. Here, we report quasielastic neutron scattering (QENS) measurements on two samples differing in water content at five temperatures below 280 K. The QENS spectra show water undergoing two different types of diffusive motion near the CuO surfaces: a “slow” translational diffusion occurring on a nanosecond time scale and a faster rotational motion. Further from the surfaces, there is “fast” translational diffusion comparable in rate to that of bulk supercooled water and the rotational motion occurring in the interfacial water. Analysis of the QENS spectra supports wetting of water to the CuO blades as seen in electron microscopy images. In addition, we observe an anomalous temperature dependence of the QENS spectra on cooling from 270 to 230 K with features consistent with a liquid–liquid phase transition. We suggest that the solvent-like properties of the coexisting bulk-like water in our CuO samples are a significant factor in determining the temperature dependence of the interfacial water’s dynamics. Our results are compared with those obtained from two well-studied substrate classes: (1) silicas that contain ordered cylindrical nanopores but have weaker hydrophilicity and (2) nanoparticles of other transition-metal oxides, such as TiO2, which share the strong hydrophilicity of our samples but lack their porosity.

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Mallamace, Francesco, Domenico Mallamace, Giuseppe Mensitieri, Sow-Hsin Chen, Paola Lanzafame, and Georgia Papanikolaou. "The Water Polymorphism and the Liquid–Liquid Transition from Transport Data." Physchem 1, no. 2 (2021): 202–14. http://dx.doi.org/10.3390/physchem1020014.

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NMR spectroscopic literature data are used, in a wide temperature-pressure range (180–350 K and 0.1–400 MPa), to study the water polymorphism and the validity of the liquid–liquid transition (LLT) hypothesis. We have considered the self-diffusion coefficient DS and the reorientational correlation time τθ (obtained from spin-lattice T1 relaxation times), measured, respectively, in bulk and emulsion liquid water from the stable to well inside the metastable supercooled region. As an effect of the hydrogen bond (HB) networking, the isobars of both these transport functions evolve with T by changing by several orders of magnitude, whereas their pressure dependence become more and more pronounced at lower temperatures. Both these transport functions were then studied according to the Adam–Gibbs model, typical of glass forming liquids, obtaining the water configurational entropy and the corresponding specific heat contribution. The comparison of the evaluated CP,conf isobars with the experimentally measured water specific heat reveals the full consistency of this analysis. In particular, the observed CP,conf maxima and its diverging behaviors clearly reveals the presence of the LLT and with a reasonable approximation the liquid–liquid critical point (LLCP) locus in the phase diagram.

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Costanzo, J. P., J. D. Litzgus, J. B. Iverson, and R. E. Lee. "Soil hydric characteristics and environmental ice nuclei influence supercooling capacity of hatchling painted turtles Chrysemys picta." Journal of Experimental Biology 201, no. 22 (1998): 3105–12. http://dx.doi.org/10.1242/jeb.201.22.3105.

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Hatchling painted turtles (Chrysemys picta) hibernate in their shallow natal nests where temperatures occasionally fall below -10 C during cold winters. Because the thermal limit of freeze tolerance in this species is approximately -4 C, hatchlings rely on supercooling to survive exposure to extreme cold. We investigated the influence of environmental ice nuclei on susceptibility to inoculative freezing in hatchling C. picta indigenous to the Sandhills of west-central Nebraska. In the absence of external ice nuclei, hatchlings cooled to -14.6 1.9 C (mean s.e.m.; N=5) before spontaneously freezing. Supercooling capacity varied markedly among turtles cooled in physical contact with sandy soil collected from nesting locales or samples of the native soil to which water-binding agents (clay or peat) had been added, despite the fact that all substrata contained the same amount of moisture (7.5 % moisture, w/w). The temperature of crystallization (Tc) of turtles exposed to frozen native soil was -1.6 0.4 C (N=5), whereas turtles exposed to frozen soil/clay and soil/peat mixtures supercooled extensively (mean Tc values approximately -13 C). Hatchlings cooled in contact with drier (less than or equal to 4 % moisture) native soil also supercooled extensively. Thus, inoculative freezing is promoted by exposure to sandy soils containing abundant moisture and little clay or organic matter. Soil collected at turtle nesting locales in mid and late winter contained variable amounts of moisture (4-15 % w/w) and organic matter (1-3 % w/w). In addition to ice, the soil at turtle nesting locales may harbor inorganic and organic ice nuclei that may also seed the freezing of hatchlings. Bulk samples of native soil, which were autoclaved to destroy any organic nuclei, nucleated aqueous solutions at approximately -7 C (Tc range -6.1 to -8.2 C). Non-autoclaved samples contained water-extractable, presumably organic, ice nuclei (Tc range -4.4 to -5.3 C). Ice nuclei of both classes varied in potency among turtle nesting locales. Interaction with ice nuclei in the winter microenvironment determines whether hatchling C. picta remain supercooled or freeze and may ultimately account for differential mortality in nests at a given locale and for variation in winter survival rates among populations.

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Knop, Inken, Stephan E. Bansmer, Valerian Hahn, and Christiane Voigt. "Comparison of different droplet measurement techniques in the Braunschweig Icing Wind Tunnel." Atmospheric Measurement Techniques 14, no. 2 (2021): 1761–81. http://dx.doi.org/10.5194/amt-14-1761-2021.

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Abstract. The generation, transport and characterization of supercooled droplets in multiphase wind tunnel test facilities is of great importance for conducting icing experiments and to better understand cloud microphysical processes such as coalescence, ice nucleation, accretion and riming. To this end, a spray system has been developed, tested and calibrated in the Braunschweig Icing Wind Tunnel. Liquid droplets in the size range of 1 to 150 µm produced by pneumatic atomizers were accelerated to velocities between 10 and 40 m s−1 and supercooled to temperatures between 0 and −20 ∘C. Thereby, liquid water contents between 0.07 and 2.5 g m−3 were obtained in the test section. The wind tunnel conditions were stable and reproducible within 3 % standard variation for median volumetric diameter (MVD) and 7 % standard deviation for liquid water content (LWC). Different instruments were integrated in the icing wind tunnel measuring the particle size distribution (PSD), MVD and LWC. Phase Doppler interferometry (PDI), laser spectroscopy with a fast cloud droplet probe (FCDP) and shadowgraphy were systematically compared for present wind tunnel conditions. MVDs measured with the three instruments agreed within 15 % in the range between 8 and 35 µm and showed high coefficients of determination (R2) of 0.985 for FCDP and 0.799 for shadowgraphy with respect to PDI data. Between 35 and 56 µm MVD, the shadowgraphy data exhibit a low bias with respect to PDI. The instruments' trends and biases for selected droplet conditions are discussed. LWCs determined from mass flow calculations in the range of 0.07–1.5 g m−3 are compared to measurements of the bulk phase rotating cylinder technique (RCT) and the above-mentioned single-particle instruments. For RCT, agreement with the mass flow calculations of approximately 20 % in LWC was achieved. For PDI 84 % of measurement points with LWC<0.5 g m−3 agree with mass flow calculations within a range of ±0.1 g m−3. Using the different techniques, a comprehensive wind tunnel calibration for supercooled droplets was achieved, which is a prerequisite for providing well-characterized liquid cloud conditions for icing tests for aerospace, wind turbines and power networks.

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Platnick, Steven, Kerry Meyer, Nandana Amarasinghe, Galina Wind, Paul A. Hubanks, and Robert E. Holz. "Sensitivity of Multispectral Imager Liquid Water Cloud Microphysical Retrievals to the Index of Refraction." Remote Sensing 12, no. 24 (2020): 4165. http://dx.doi.org/10.3390/rs12244165.

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A cloud property retrieved from multispectral imagers having spectral channels in the shortwave infrared (SWIR) and/or midwave infrared (MWIR) is the cloud effective particle radius (CER), a radiatively relevant weighting of the cloud particle size distribution. The physical basis of the CER retrieval is the dependence of SWIR/MWIR cloud reflectance on the cloud particle single scattering albedo, which in turn depends on the complex index of refraction of bulk liquid water (or ice) in addition to the cloud particle size. There is a general consistency in the choice of the liquid water index of refraction by the cloud remote sensing community, largely due to the few available independent datasets and compilations. Here we examine the sensitivity of CER retrievals to the available laboratory index of refraction datasets in the SWIR and MWIR using the retrieval software package that produces NASA’s standard Moderate Resolution Imaging Spectroradiometer (MODIS)/Visible Infrared Imaging Radiometer suite (VIIRS) continuity cloud products. The sensitivity study incorporates two laboratory index of refraction datasets that include measurements at supercooled water temperatures, one in the SWIR and one in the MWIR. Neither has been broadly utilized in the cloud remote sensing community. It is shown that these two new datasets can significantly change CER retrievals (e.g., 1–2 µm) relative to common datasets used by the community. Further, index of refraction data for a 265 K water temperature gives more consistent retrievals between the two spectrally distinct 2.2 µm atmospheric window channels on MODIS and VIIRS. As a result, 265 K values from the SWIR and MWIR index of refraction datasets were adopted for use in the production version of the continuity cloud product. The results indicate the need to better understand temperature-dependent bulk water absorption and uncertainties in these spectral regions.

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Thompson, Gregory, Paul R. Field, Roy M. Rasmussen, and William D. Hall. "Explicit Forecasts of Winter Precipitation Using an Improved Bulk Microphysics Scheme. Part II: Implementation of a New Snow Parameterization." Monthly Weather Review 136, no. 12 (2008): 5095–115. http://dx.doi.org/10.1175/2008mwr2387.1.

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Abstract A new bulk microphysical parameterization (BMP) has been developed for use with the Weather Research and Forecasting (WRF) Model or other mesoscale models. As compared with earlier single-moment BMPs, the new scheme incorporates a large number of improvements to both physical processes and computer coding, and it employs many techniques found in far more sophisticated spectral/bin schemes using lookup tables. Unlike any other BMP, the assumed snow size distribution depends on both ice water content and temperature and is represented as a sum of exponential and gamma distributions. Furthermore, snow assumes a nonspherical shape with a bulk density that varies inversely with diameter as found in observations and in contrast to nearly all other BMPs that assume spherical snow with constant density. The new scheme’s snow category was readily modified to match previous research in sensitivity experiments designed to test the sphericity and distribution shape characteristics. From analysis of four idealized sensitivity experiments, it was determined that the sphericity and constant density assumptions play a major role in producing supercooled liquid water whereas the assumed distribution shape plays a lesser, but nonnegligible, role. Further testing using numerous case studies and comparing model results with in situ and other observations confirmed the results of the idealized experiments and are briefly mentioned herein, but more detailed, microphysical comparisons with observations are found in a companion paper in this series (Part III, forthcoming).

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Mallamace, Francesco, Domenico Mallamace, Sow-Hsin Chen, Paola Lanzafame, and Georgia Papanikolaou. "Hydrophilic and Hydrophobic Effects on the Structure and Themodynamic Properties of Confined Water: Water in Solutions." International Journal of Molecular Sciences 22, no. 14 (2021): 7547. http://dx.doi.org/10.3390/ijms22147547.

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NMR spectroscopy is used in the temperature range 180–350 K to study the local order and transport properties of pure liquid water (bulk and confined) and its solutions with glycerol and methanol at different molar fractions. We focused our interest on the hydrophobic effects (HE), i.e., the competition between hydrophilic and hydrophobic interactions. Nowadays, compared to hydrophilicity, little is known about hydrophobicity. Therefore, the main purpose of this study is to gain new information about hydrophobicity. As the liquid water properties are dominated by polymorphism (two coexisting liquid phases of high and low density) due to hydrogen bond interactions (HB), creating (especially in the supercooled regime) the tetrahedral networking, we focused our interest to the HE of these structures. We measured the relaxation times (T1 and T2) and the self-diffusion (DS). From these times, we took advantage of the NMR property to follow the behaviors of each molecular component (the hydrophilic and hydrophobic groups) separately. In contrast, DS is studied in terms of the Adam–Gibbs model by obtaining the configurational entropy (Sconf) and the specific heat contributions (CP,conf). We find that, for the HE, all of the studied quantities behave differently. For water–glycerol, the HB interaction is dominant for all conditions; water–methanol, two different T-regions above and below 265 K are observable, dominated by hydrophobicity and hydrophilicity, respectively. Below this temperature, where the LDL phase and the HB network develops and grows, with the times and CP,conf change behaviors leading to maxima and minima. Above it, the HB becomes weak and less stable, the HDL dominates, and hydrophobicity determines the solution.

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Jordan, James R., Satoshi Kimura, Paul R. Holland, Adrian Jenkins, and Matthew D. Piggott. "On the Conditional Frazil Ice Instability in Seawater." Journal of Physical Oceanography 45, no. 4 (2015): 1121–38. http://dx.doi.org/10.1175/jpo-d-14-0159.1.

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AbstractIt has been suggested that the presence of frazil ice can lead to a conditional instability in seawater. Any frazil forming in the water column reduces the bulk density of a parcel of frazil–seawater mixture, causing it to rise. As a result of the pressure decrease in the freezing point, this causes more frazil to form, causing the parcel to accelerate, and so on. This study uses linear stability analysis and a nonhydrostatic ocean model to study this instability. The authors find that frazil ice growth caused by the rising of supercooled water is indeed able to generate a buoyancy-driven instability. Even in a gravitationally stable water column, the frazil ice mechanism can still generate convection. The instability does not operate in the presence of strong density stratification, high thermal driving (warm water), a small initial perturbation, high background mixing, or the prevalence of large frazil ice crystals. In an unstable water column, the instability is not necessarily expressed in frazil ice at all times; an initial frazil perturbation may melt and refreeze. Given a large enough initial perturbation, this instability can allow significant ice growth. A model shows frazil ice growth in an Ice Shelf Water plume several kilometers from an ice shelf, under similar conditions to observations of frazil ice growth under sea ice. The presence of this instability could be a factor affecting the growth of sea ice near ice shelves, with implications for Antarctic Bottom Water formation.

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Khain, A., and A. Pokrovsky. "Simulation of Effects of Atmospheric Aerosols on Deep Turbulent Convective Clouds Using a Spectral Microphysics Mixed-Phase Cumulus Cloud Model. Part II: Sensitivity Study." Journal of the Atmospheric Sciences 61, no. 24 (2004): 2983–3001. http://dx.doi.org/10.1175/jas-3281.1.

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Abstract Effects of different size distributions of cloud condensational nuclei (CCN) on the evolution of deep convective clouds under dry unstable continental thermodynamic conditions are investigated using the spectral microphysics Hebrew University Cloud Model (HUCM). In particular, high supercooled water content just below the level of homogeneous freezing, as well as an extremely high concentration of ice crystals above the level, observed recently by Rosenfeld and Woodley at the tops of growing clouds in Texas, were successfully reproduced. Numerical experiments indicate a significant decrease in accumulated precipitation in smoky air. The fraction of warm rain in the total precipitation amount increases with a decrease in the CCN concentration. The fraction is low in smoky continental air and is dominating in clean maritime air. As warm rain is a smaller fraction of total precipitation, the decrease in the accumulated rain amount in smoky air results mainly from the reduction of melted precipitation. It is shown that aerosols significantly influence cloud dynamics leading to the elevation of the level of precipitating particle formation. The falling down of these particles through dry air leads to a loss in precipitation. Thus, close coupling of microphysical and dynamical aerosol effects leads to the rain suppression from clouds arising in dry smoky air. The roles of freezing, CCN penetration through lateral cloud boundaries, and turbulent effects on cloud particles collisions are evaluated. Results, obtained using spectral microphysics, were compared with those obtained using two well-known schemes of bulk parameterization. The results indicate that the bulk parameterization schemes do not reproduce well the observed cloud microstructure.

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Journal articles on the topic 'Supercooled Bulk Water'

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