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outlet glacier

a valley glacier which drains an inland ice sheet or ice cap and flows through a gap in peripheral mountains.
Topic: 
glaciers

ozone

a nearly colorless (but faintly blue) gaseous form of oxygen, with a characteristic odor like chlorine; has a formula of O3 and a molecular weight of 48; found in trace quantities in the earth's atmosphere at all times, primarily in the stratosphere between heights of about 10 to 50 kilometers (6 to 31 miles; the ozonosphere or ozone shield) where its production results from photochemical processes involving ultraviolet radiation; its maximum concentration occurs between 20 to 25 kilometers (12 to 16 miles); in the lower atmosphere, ozone is commonly formed as a product of electrical discharges through the air.
Topic: 
climatology and meteorology

ozone shield

stratospheric ozone layer, giving protection to the earth's surface due to intense absorption of harmful solar ultraviolet radiation by the gas.
Topic: 
climatology and meteorology

ozonosphere

stratospheric ozone layer, giving protection to the earth's surface due to intense absorption of harmful solar ultraviolet radiation by the gas.
Topic: 
climatology and meteorology

pack ice

ice that is not attached to the shoreline and drifts in response to winds, currents, and other forces; some prefer the generic term drift ice, and reserve pack ice to mean drift ice that is closely packed.
Topic: 
sea ice

palsa

a peaty permafrost mound possessing a core of alternating layers of segregated ice and peat or mineral soil material.
Topic: 
frozen ground or permafrost

palsa bog

a poorly-drained lowland underlain by organic-rich sediments, which contains perennially frozen peat bodies (peat plateaux) and, occasionally, palsas.
Topic: 
frozen ground or permafrost

pancake ice

pieces of new ice approximately circular, up to 10 centimeters (4 inches) thick and 0.03 to 3 meters (0.1 to 9.8 feet) in diameter, with raised edges that form from rubbing against each other; formed from the freezing together of grease ice, slush or shuga, or the reaking up of ice rind or nilas.
(Photo courtesy of the National Oceanic and Atmospheric Administration/Department of Commerce.)
Topic: 
sea ice

parameter

(1) a term used loosely by many meteorologists for almost any meteorological quantity or element (2) an arbitrary constant or variable appearing in a mathematical expression; changing it can give various outcomes for the phenomena represented.
Topic: 
climatology and meteorology

partial pressure

in a mixture of gases, each gas has a partial pressure, which is the pressure the gas would have if it occupied that volume alone.
Topic: 
climatology and meteorology

partially-bonded permafrost

ice-bearing permafrost in which some of the soil particles are not held together by ice.
Topic: 
frozen ground or permafrost

passive construction methods in permafrost

special design and construction methods used for engineering works in permafrost areas where preservation of the frozen condition is feasible.
Topic: 
frozen ground or permafrost

passive single-phase thermal pile

a foundation pile provided with a single-phase natural convection cooling system to remove heat from the ground.
Topic: 
frozen ground or permafrost

passive two-phase thermal pile

a foundation pile provided with a two-phase natural convection cooling system to remove heat from the ground.
Topic: 
frozen ground or permafrost

past weather

predominant characteristic of the weather which had existed at an observing station during a given period of time (during the preceding hour or six hours), specified in the international synop code.
Topic: 
climatology and meteorology

patch

a collection of pack ice, less than 10 kilometers (6.2 miles) across, whose limits can be seen from the masthead.
Topic: 
sea ice

patterned ground

a general term for any ground surface exhibiting a discernibly ordered, more or less symmetrical, morphological pattern of ground and, where present, vegetation.
A photograph taken from the air reveals patterned ground surrounding thaw lakes in Alaska’s Arctic National Wildlife Refuge. —Credit: U.S. Fish and Wildlife Service
Topic: 
frozen ground or permafrost

peat

a deposit consisting of decayed or partially decayed humified plant remains.
Topic: 
frozen ground or permafrost

peat hummock

a hummock consisting of peat.
Topic: 
frozen ground or permafrost

peat plateau

a generally flat-topped expanse of peat, elevated above the general surface of a peatland, and containing segregated ice that may or may not extend downward into the underlying mineral soil.
Topic: 
frozen ground or permafrost

peatland

peat-covered terrain.
Topic: 
frozen ground or permafrost

penitents

the extreme relief of ablation hollows found most often at high altitudes in the tropics; the resulting spikes of snow resemble repentant souls.
Topic: 
glaciers
snow

pereletok

a layer of frozen ground which forms as part of the seasonally frozen ground (in areas free of permafrost or with a lowered permafrost table); remains frozen throughout one or several summers, and then thaws.
Topic: 
frozen ground or permafrost

perennial snow

snow that persists on the ground year after year.
Topic: 
snow

periglacial

the conditions, processes and landforms associated with cold, nonglacial environments.
Topic: 
frozen ground or permafrost
glaciers

periglacial phenomena

landforms and soil characteristics produced by periglacial processes.
Topic: 
frozen ground or permafrost
glaciers

periglacial processes

processes associated with frost action in cold, nonglacial environments.
Topic: 
frozen ground or permafrost
glaciers

permacrete

an artificial mixture of frozen soil materials cemented by pore ice, which forms a concrete-like construction material used in cold regions.
Topic: 
frozen ground or permafrost

permafrost

layer of soil or rock, at some depth beneath the surface, in which the temperature has been continuously below 0°C for at least several years; it exists where summer heating fails to reach the base of the layer of frozen ground.

Topic: 
climatology and meteorology
frozen ground or permafrost

permafrost aggradation

a naturally or artificially caused increase in the thickness and/or areal extent of permafrost.
Topic: 
frozen ground or permafrost

permafrost base

the lower boundary surface of permafrost, above which temperatures are perennially below 0 degrees Celsius (cryotic) and below which temperatures are perennially above 0 degrees Celsius (noncryotic).
Topic: 
frozen ground or permafrost

permafrost boundary

(1) the geographical boundary between the continuous and discontinuous permafrost zones (2) the margin of a discrete body of permafrost.
Topic: 
frozen ground or permafrost

permafrost degradation

a naturally or artificially caused decrease in the thickness and/or areal extent of permafrost.
Topic: 
frozen ground or permafrost

permafrost extent

the total geographic area containing some amount of permafrost; typically reported in square kilometers.

permafrost limit

outermost (latitudinal) or lowest (altitudinal) limit of the occurrence of permafrost.
Topic: 
frozen ground or permafrost

permafrost region

a region in which the temperature of some or all of the ground below the seasonally freezing and thawing layer remains continuously at or below 0 degrees Celsius for at least two consecutive years.
Topic: 
frozen ground or permafrost

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