Scientists have for the first time calculated the rate at which water crystallizes to form ice in a realistic computer molecule of water molecules.
In a breakthrough research, a supercomputer offered a complete insight into the mechanism by which water turns from liquid state to a crystalline solid.
The study conducted by two researchers from Princeton University, Amir Haji-Akbari, a postdoctoral research associate, and Pablo Debenedetti, a professor of chemical and biological engineering, they studied the process by which, as the temperature drops, water molecules begin to attach o each other to form a solid ice blob within the surrounding liquid.
This knowledge of ice formation or freezing could help us in improving weather forecasts. Understanding ice formation adds to our knowledge of how cold temperatures affect both living and non-living things. It will also show how living cells respond to cold and how ice forms in clouds at high altitudes.
The whole process of formation of ice is referred as nucleation.
To study the process, the researcher used a computerized model of water that mimcs the two atoms of hydrogen and one atom of oxygen found in real water.
By the computer simulations, the researchers calculated the average amount of time it takes for the first critical nucleus to form at a temperature of about minus 43 degrees Celsius, which is representative of conditions in high-altitude clouds. They found that, for a cubic meter of pure water, the amount of time it takes for a critical nucleus to form is about one-millionth of a second.
“The main significance of this work is to show that it is possible to calculate the nucleation rate for relatively accurate models of water,” said Haji-Akbari.
The study was published in the journal PNAS.