Editing Polar low (section)

==Formation==
{{See also|Cyclogenesis}}
Polar lows form for a number of different reasons, and a spectrum of systems is observed on satellite imagery. A number of lows develop on horizontal temperature gradients through [[baroclinic instability]], and these can have the appearance of small frontal depressions. At the other extreme are the polar lows with extensive [[cumulonimbus]] clouds, which are often associated with cold pools in the mid- to upper-[[troposphere]].  During winter, when cold-core lows with temperatures in the mid-levels of the troposphere reach {{convert|-45|C|F}} move over open waters, deep convection forms which allows polar low development to become possible (polar lows usually occur with cold air outbreaks<ref>{{Cite journal |last1=Moreno-Ibáñez |first1=Marta |last2=Laprise |first2=René |last3=Gachon |first3=Philippe |date=2021-01-01 |title=Recent advances in polar low research: current knowledge, challenges and future perspectives |journal=Tellus A: Dynamic Meteorology and Oceanography |language=en |volume=73 |issue=1 |pages=1–31 |doi=10.1080/16000870.2021.1890412 |s2cid=233807634 |issn=1600-0870|doi-access=free |bibcode=2021TellA..7390412M }}</ref>).<ref>{{cite book|url=https://books.google.com/books?id=-tBa1DWYoDIC&q=cold+core+low+book&pg=PA227|title=Polar lows: mesoscale weather systems in the polar regions|page=224|author=Erik A. Rasmussen and John Turner|year=2003|publisher=Cambridge University Press|access-date=2011-01-27|isbn=978-0-521-62430-5}}</ref>