Against the popular belief or what people might have been taught, water doesn't freeze to the ice at 32 degrees F (zero degrees C). Beginning with the process of nucleation, controlling or knowing at what temperature water will freeze is crucially essential to answering the question like whether or not there will be sufficient snow on the ski slope or whether or not it will rain tomorrow.
Nature has formatted ways of controlling the formation of ice. Based on that, a paper published in the Journal of the American Chemical Society, professor Valeria Molinero of University of Utah and her colleagues reveal how vital proteins produced in insects and bacteria can either promote or inhibit the formation of ice, based on their length and their ability to team up to form large ice-building surfaces. There was a broad application from the results especially in understanding precipitation in clouds.
Molinero said that they are currently able to predict the temperature at which the bacterium is going to nucleate ice depending on how much ice-nucleating proteins it has. Not only that, they were able to predict the temperature at which the antifreeze proteins, which are quite small and typical don't work at quite low temperatures, can nucleate ice.
How do they then define nucleation?
For some time now, life likes to mess with ice. Fish, insects, and plants all generate different varieties of antifreeze proteins to help them survive in below-freezing conditions. Also, plant pathogens, especially the bacterium Pseudomonas syringae, make use of proteins that promote the formation of ice to induce damage in their hosts.
Pure water that has no impurities may not freeze until it reaches -35 degree C (-31 degree F), the temperature at which the water molecules will spontaneously arrange into a crystal lattice and begin to recruit other molecules to join.
This study matters because of the implication of such a finding extend to the future of water on Earth. The beginning of precipitation is ice which nucleates and grows until it is heavy enough to precipitate. At high altitudes where it is colder, soot and dust can do the job of triggering nucleation. But at lower elevations, it is not dust that triggers nucleation; it is bacteria.
Molinero said that the ability to predict whether the clouds are going to freeze or not is super essential in climate models since the formation of ice determines precipitation and also the proportion of solar energy reflected and absorbed by our atmosphere. The difficulty forecasting if ice is going to nucleate or not in clouds is a significant limitation to the predictive ability of weather and climate models.
