polar air mass


Also found in: Dictionary, Thesaurus, Acronyms.

polar air mass

polar air mass
Polar air mass as it affects the United Kingdom.
That air mass that originates in high latitudes. Polar air masses are of two types—polar maritime and polar continental. The polar continental has its source in continental Eastern Europe, Siberia, and Canada, and it brings very cold weather to the United Kingdom and United States in winter. This air mass is characterized by very cold dry air. Polar maritime air often originates in the Greenland or Gulf of Alaska regions and spreads across the United Kingdom or United States from a northwesterly direction. It is humid and unstable.
References in periodicals archive ?
The jet stream - a narrow, variable band of westerly air currents miles above the Earth - is strongest in winter, when boundaries between hot tropical and cold polar air masses are most pronounced.
In this trimester, the sequence of weather types caused less of an impact on the blooms of cyanobacteria and was mainly related to the low temperatures originating from the constant presence of the Polar air masses. However, the front still acted as a promoter of the mixing process in addition to the meeting of the air masses of the mTA and mPA.
The team's new analyses of ground-based weather data bolster this notion by showing that some polar air masses containing elevated concentrations of bromine monoxide (BrO) had on the previous day passed over areas of fresh sea ice, which probably sported frost flowers.
The tropical and polar air masses that invade North America tend to travel in an easterly direction because they interact with the eastward-moving jet stream five to eight miles above the surface.
The other experts did not agree with Rebelo's prediction, and Carlos Magno stated that he believed the El Nino phenomenon this year will create a climate barrier that will prevent the polar air masses to penetrate into the coffee belt.