1. Astronomically, between the winter solstice and vernal equinox in the Northern Hemisphere, and the summer solstice and autumnal equinox in the Southern Hemisphere; the coldest season of the year; t
he "low sun" season during which the sun is over the opposite hemisphere; the "hibernal" season. Popularly and for most meteorological purposes, winter is taken to include December, January, and February in the Northern Hemisphere, and in the Southern Hemisphere, June, July, and August; the opposite of summer. 2. See Blackthorn winter.
Accumulation integrated over the winter season. Winter accumulation is not the same as winter mass balance. It is generally larger because some of the accumulated mass may be lost by ablation. Mass-ba
lance measurements by the glaciological method generally measure winter mass balance and not winter accumulation.
A type of glacier, typically at mid-latitudes or high latitudes, on which the regional seasonality leads to accumulation predominating in the winter season and ablation predominating in the summer sea
son.
The preparation of equipment for operation in conditions of winter weather. This applies to preparation not only for cold temperatures, but also for snow, ice, and strong winds.
The time span from the start of the mass-balance year to the time of maximum glacier mass. The term is best suited to glaciers of winter-accumulation type. In the stratigraphic system the winter seaso
n ends when the glacier has attained maximum mass. In the floating-date system and the fixed-date system, the mass is not necessarily at its Annual minimum or maximum when the winter season starts or ends.
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 f
rom 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.