Even far below freezing, ice’s surface begins melting as temperatures rise

Using imaging tools at the U.S. Department of Energy's (DOE) Argonne National Laboratory, researchers have detected a phenomenon known as pre-melting at temperatures far lower than those previously observed. Pre-melting is the reason a patch of ice can be slippery even on a frigid, clear day. Although the spot is frozen, some part at the surface is wet. To make this discovery, the team used Argonne's Center for Nanoscale Materials, a DOE Office of Science user facility that enabled them grow and observe ice nanocrystals at temperatures below minus 200 degrees Fahrenheit.