Entropy and dynamic properties of water below the homogeneous nucleation temperature

Controversy exists regarding the possible existence of a transition between the liquid and glassy states of water. Here we use experimental measurements of the entropy, specific heat, and enthalpy of both liquid and glassy water to construct thermodynamically-plausible forms of the entropy in the difficult-to-probe region between 150 K and 236 K. We assume there is no discontinuity in the entropy of the liquid in this temperature range, and use the Adam-Gibbs theory -- which relates configurational entropy to dynamic behavior -- to predict that dynamic quantities such as the diffusion constant and the viscosity pass through an inflection where the liquid behavior changes from that of an extremely ``fragile'' liquid to that of a ``strong'' liquid.