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Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

Small, shallow depression which forms mainly in winter over some high-latitude seas within a polar or arctic air mass.  5, record 1, English, - polar%20low

Record number: 1, Textual support number: 1 CONT

When arctic-origin air in winter flows southward (northward in the southern hemisphere) across (relatively) warmer seas, strong surface heating acts both to enhance the degree of instability, and trigger vigorous moist convective towers. This is sufficient alone to give rise to heavy, wintry showers/cumulonimbus clusters etc., but often marked troughing, or even a closed circulation in the isobaric flow is found; the resultant low-level convergence/positive vorticity enhancement, plus the localised concentration of the latent heat energy released, enhances development within the system, and an intense (but synoptically small) area of rain, hail, sleet or snow & squally winds can result - a polar low (or polar depression or polar meso-cyclone in some texts).  2, record 1, English, - polar%20low

Record number: 1, Textual support number: 2 CONT

What is a polar low? Part of a diverse group of mesoscale weather systems (polar meso-cyclones). ... [There is] three types of polar meso-cyclones: -jet streak type, -arctic front type, -cold low type.  6, record 1, English, - polar%20low

Record number: 1, Textual support number: 1 OBS

Polar mesocyclones: a term now used to encompass the whole 'family' of disturbances resulting from arctic air flowing equatorward over progressively warmer seas; the term 'polar low' is now often used only for 'extreme' systems where gale or near gale-force winds are observed.  7, record 1, English, - polar%20low

Record number: 1, Textual support number: 2 OBS

Its motion is approximately the same as the air stream in which it is embedded.  5, record 1, English, - polar%20low

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Petite dépression peu profonde qui se forme principalement en hiver dans une masse d'air polaire ou arctique située sur certaines mers des hautes latitudes.  1, record 1, French, - d%C3%A9pression%20polaire

Record number: 1, Textual support number: 1 OBS

Son mouvement est approximativement le même que celui du courant atmosphérique dans lequel elle se situe.  1, record 1, French, - d%C3%A9pression%20polaire

Record 1,  Textual support,  Spanish

Record number: 1, Textual support number: 1 DEF

Depresión pequeña y poco profunda que se forma dentro de una masa de aire polar o ártico, especialmente en invierno, sobre los mares polares.  1, record 1, Spanish, - baja%20polar

Record number: 1, Textual support number: 1 OBS

Se mueve siguiendo, aproximadamente, la dirección de la corriente de aire en que está inserta.  1, record 1, Spanish, - baja%20polar