This book has comprehensively introduced the geophysics of snow and ice on Earth or the Earth’s cryosphere. Snow is a form of ice but distinguished due to its different qualities and appearances. Snow and ice are dominant factors in the atmosphere, on water surfaces, and in the ground in cold regions of nature. The polar ice sheets in Antarctica and Greenland contain by far most of the ice volume, while seasonal snow and sea ice form the largest visible area of the cryosphere on the Earth’s surface. In general, snow and ice occur where the air temperature of the coldest month is below the freezing point of pure water, and perennial ice can be found in tundra and polar climates where summers are cold [1–3].