Fr.: glace d'eau
Water in the → solid state, produced by freezing → liquid water; frozen water. Ice forms at or below a temperature of 0°C. Ice is less dense than liquid water because it expands during the process of freezing. This is because the molecular arrangement taken by ice leads to an increase in volume and a decrease in density. → maximum density of water
Fr.: solstice d'hiver
The moment in the northern hemisphere when the → Sun attains its lowest → declination of -23°26' (or -23°.44) with respect the → equator plane. It happens when the Earth's axis is orientated directly away from the Sun, on 21 or 22 December. During the northern winter solstice the Sun appears to be directly overhead at noon for places situated at → latitude 23.44 degrees south, known as the → tropic of Capricorn. The winter solstice can occur at any moment during the day. Two successive winter solstices are shifted in time by about 6 h. The winter solstice in the northern hemisphere is the → summer solstice in the southern hemisphere.