Analysis of the effect of water activity on ice formation using a new thermodynamic framework

被引:19
作者
Barahona, D. [1 ]
机构
[1] NASA Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA
关键词
SOLID-LIQUID INTERFACE; MOLECULAR-DYNAMICS SIMULATION; SUPERCOOLED WATER; AQUEOUS-SOLUTIONS; ATMOSPHERIC APPLICATIONS; FREEZING NUCLEATION; TROPICAL TROPOPAUSE; CIRRUS CLOUDS; MODEL; DROPLETS;
D O I
10.5194/acp-14-7665-2014
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
In this work a new thermodynamic framework is developed and used to investigate the effect of water activity on the formation of ice within supercooled droplets. The new framework is based on a novel concept where the interface is assumed to be made of liquid molecules "trapped" by the solid matrix. It also accounts for the change in the composition of the liquid phase upon nucleation. Using this framework, new expressions are developed for the critical ice germ size and the nucleation work with explicit dependencies on temperature and water activity. However unlike previous approaches, the new model does not depend on the interfacial tension between liquid and ice. The thermodynamic framework is introduced within classical nucleation theory to study the effect of water activity on the ice nucleation rate. Comparison against experimental results shows that the new approach is able to reproduce the observed effect of water activity on the nucleation rate and the freezing temperature. It allows for the first time a phenomenological derivation of the constant shift in water activity between melting and nucleation. The new framework offers a consistent thermodynamic view of ice nucleation, simple enough to be applied in atmospheric models of cloud formation.
引用
收藏
页码:7665 / 7680
页数:16
相关论文
共 60 条
  • [1] Initiation of the ice phase by marine biogenic surfaces in supersaturated gas and supercooled aqueous phases
    Alpert, Peter A.
    Aller, Josephine Y.
    Knopf, Daniel A.
    [J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 2011, 13 (44) : 19882 - 19894
  • [2] [Anonymous], 2013, GEOSCIENTIFIC MODEL, DOI DOI 10.5194/GMDD-6-5289-2013
  • [3] [Anonymous], 1998, Microphysics of clouds and precipitation
  • [4] Solidification microstructures and solid-state parallels: Recent developments, future directions
    Asta, M.
    Beckermann, C.
    Karma, A.
    Kurz, W.
    Napolitano, R.
    Plapp, M.
    Purdy, G.
    Rappaz, M.
    Trivedi, R.
    [J]. ACTA MATERIALIA, 2009, 57 (04) : 941 - 971
  • [5] A new look at homogeneous freezing of water
    Baker, MB
    Baker, M
    [J]. GEOPHYSICAL RESEARCH LETTERS, 2004, 31 (19) : L191021 - 4
  • [6] On the ice nucleation spectrum
    Barahona, D.
    [J]. ATMOSPHERIC CHEMISTRY AND PHYSICS, 2012, 12 (08) : 3733 - 3752
  • [7] Dynamical states of low temperature cirrus
    Barahona, D.
    Nenes, A.
    [J]. ATMOSPHERIC CHEMISTRY AND PHYSICS, 2011, 11 (08) : 3757 - 3771
  • [8] Sensitivity of the global distribution of cirrus ice crystal concentration to heterogeneous freezing
    Barahona, D.
    Rodriguez, J.
    Nenes, A.
    [J]. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2010, 115
  • [9] Monitoring ice nucleation in pure and salty water via high-speed imaging and computer simulations
    Bauerecker, Sigurd
    Ulbig, Peter
    Buch, Victoria
    Vrbka, Lubos
    Jungwirth, Pavel
    [J]. JOURNAL OF PHYSICAL CHEMISTRY C, 2008, 112 (20) : 7631 - 7636
  • [10] Simulating nucleation of molecular solids
    Black, Simon
    [J]. PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, 2007, 463 (2087): : 2799 - 2811