the point in time when the vertical rays of the sun are striking either the Tropic of Cancer (23 degrees, 30 minutes N, the summer solstice in the northern hemisphere) or the Tropic of Capricorn (23 degrees, 30 minutes S, the winter solstice in the northern hemisphere); represents the longest or shortest day of the year; in the northern hemisphere, the summer solstice falls on or about 21 June, and the winter solstice on or about 22 December.
a patterned ground form that is equidimensional in several directions, with a dominantly circular outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.
a type of patterned ground with cells that are equidimensional in several directions, neither dominantly circular nor polygonal, with a sorted appearance commonly due to borders of stones surrounding central areas of finer material.
a patterned ground form that is equidimensional in several directions, with a dominantly polygonal outline, and a sorted appearance commonly due to a border of stones surrounding a central area of finer material.
patterned ground with a striped and sorted appearance, due to parallel strips of stones and intervening strips of finer material, oriented down the steepest available slope.
90° S latitude; one of the two points where the Earth's axis of rotation meets the Earth's surface (the other being the north pole, diametrically opposite).
specific heat capacity
the amount of heat required to raise the temperature of a unit mass of a substance by one degree.
(1) (North American usage) permafrost underlying 10 - 50% of the exposed land surface (2) (Russian usage) permafrost underlying 5 - 30% of the exposed land surface.
either of the two points of intersection of the sun's apparent annual path and the plane of the earth's equator; in the northern hemisphere, the spring (vernal) equinox falls on or about 21 March, and the autumnal equinox on or about 22 September.
air mass having static stability in its lower layers; it is free from convection, has a low degree of turbulence and may have stratiform clouds or fog, or no clouds.
thick ridges that become grounded during the winter and become part of the fast ice zone; while the rest of the fast ice melts during the summer, a stamukhi remains throughout the summer attached to the ocean bottom.
Statistical measurement of the variation in a distribution: In science, standard deviation serves as measure of the spread of the data, or how likely a data point will fall close to the mean.
static cryosol
a mineral soil showing little or no evidence of cryoturbation, with permafrost within 1 meter (3.3 feet) below the surface.
evaporation fog formed when water vapor is added to air which is much colder than the vapor's source; most commonly, when very cold air drifts across relatively warm water; also called sea smoke.
in meteorology, a basic fluid flow which exerts a strong influence upon the direction of movement of disturbances embedded in it; in the atmosphere, it is usually an air flow in the middle or upper troposphere which govern directions of the disturbances at low levels.
a fissure at the junction between an inland ice sheet, ice piedmont or ice rise and an ice shelf, the latter being subject to the rise and fall of the tide.
a principal low-level cloud type (cloud genus), predominantly stratiform, in the form of relatively low gray and/or whitish layer, sheet or patch; its elements are often arranged in bands or rolls that lie across the wind; light rain, snow, or sleet may fall from stratocumulus.
a layer of the Earths atmosphere, between the troposphere and mesosphere, that is stratified in temperature such that cooler layers are closer to the Earths surface, and warmer layers are higher up (opposite the pattern of the troposphere near the Earths surface); situated between about 10 to 50 kilometers (6 to 31 miles) in altitude above the surface of the moderate latitudes; at the poles, it starts at about 8 km in altitude; composition is basically the same as that of the lower atmosphere, with the addition of ozone.
a principal low-level cloud type (cloud genus) in the form of a low-altitude, light to dark gray cloud layer with a rather uniform base; generally diffuse and dull; this cloud formation has little structure and looks like fog, except that it is above the ground, stratus does not usually produce precipitation, but when it does occur, it is in the form of minute particles, such as drizzle, ice crystals, or fine snow grains.
a peatland with roughly parallel narrow ridges of peat dominated by fenland vegetation interspersed with slight depressions, many of which contain shallow pools.
a long narrow area of pack ice, about 1 kilometer (0.6 mile) or less in width, usually composed of small fragments detatched from the main mass of ice, and run together under the influence of wind or current.