The common image of a desert is a vast, scorching landscape of sand dunes, but this perception is misleading. Deserts are defined by a lack of precipitation, meaning dryness is the only true measure of aridity. This meteorological standard leads to a surprising classification for the northernmost region of the planet. Although covered in ice and perpetual cold, the North Pole region is scientifically classified as a polar desert.
What Defines a Desert
Climatologists define a desert based primarily on the amount of annual moisture it receives, regardless of whether that moisture is rain or snow. The condition for an arid climate is an imbalance where potential evaporation exceeds precipitation. A widely accepted guideline classifies an area as a desert if it receives less than 250 millimeters (about 10 inches) of precipitation annually. Temperature is only used to distinguish the type of desert, not the fact of its existence, making the presence of sand or high temperatures secondary to overall dryness.
Aridity Measurements in the North Pole Region
Applying the arid climate criteria to the central Arctic Ocean, the North Pole region definitively meets the threshold of a desert. The central Arctic Basin typically receives low annual precipitation, ranging from 100 to 200 millimeters. Interior areas of the Greenland ice sheet may receive less than 100 millimeters. The moisture that falls is mostly fine snow crystals or ice fog, which contributes to the arid conditions. This light, dry snowfall is easily redistributed by wind, resulting in low accumulation of available moisture. The atmosphere’s overall dryness is caused by the low frequency of cyclones and the great distance from warm, open water sources. The central Arctic’s precipitation levels are comparable to those found in non-polar deserts, confirming its classification.
The Difference Between Cold and Hot Deserts
The physical difference between a cold desert like the North Pole and a hot desert like the Sahara lies in the rate of water loss, or evaporation. In hot deserts, high temperatures drive rapid evaporation, quickly removing moisture and leading to the classic dry, sandy landscape. Although the air can hold significantly more water vapor, precipitation remains scarce. In the Arctic’s cold desert environment, near-freezing temperatures drastically slow the rate of evaporation and sublimation. This minimal moisture loss allows accumulated snow and ice to persist on the surface for extended periods, sometimes centuries. The ice cover is a relic of past precipitation events that never melted or evaporated away, creating the deceptive appearance of an environment rich in water. The low temperature effectively locks the water away as solid ice, making it biologically unavailable and maintaining the climate’s fundamental aridity.
Arctic Life in a Desert Climate
The biological consequences of a cold, arid environment are reflected in the sparse distribution of life. Where landmasses exist, low moisture and permafrost limit terrestrial plant life to hardy, low-lying species like mosses and lichens. Plants have adapted compact growth forms, such as cushions and rosettes, which help reduce exposure to drying winds and conserve available moisture. The most visible life in the polar desert is associated with the marine environment, drawing nutrients from the ocean below the ice. Apex predators like polar bears, seals, and seabirds exploit the productivity of the Arctic Ocean ecosystem. These animals rely on thick layers of fat, or blubber, and specialized coats to insulate against the extreme cold, an adaptation necessary for survival in this freezing and dry climate.