What is Polar low?
{{nosources|date=April 2009}} [[File:Sea of Japan polar low 2009-12-20 0213Z.jpg|thumb|right|Polar low over the [[Sea of Japan]] in [[December]] [[2009]]]] A '''polar low''' is a small sized and short-lived [[atmosphere|atmospheric]] [[low pressure area|low pressure system]] that is found over the ocean areas pole ward of the main [[polar front]] in both the [[Northern Hemisphere|Northern]] and [[Southern Hemisphere]]s. The systems usually have a horizontal length scale of less than 1,000&nbsp;km and live for less than a couple of days. They are part of the larger class of [[mesocyclone|mesoscale]] weather systems. Polar lows can be difficult to detect using standard weather reports and are a problem to high-latitude operations, such as shipping and gas and oil platforms. Polar lows have been also known as by using many other terms, such as ''comma cloud'', ''mesocyclone'', ''polar mesoscale vortex'', ''Arctic hurricane'', ''Arctic low'', and ''cold air depression''. Today the term is usually set aside for the more-energetic systems that have near-surface winds of at least gale force (17&nbsp;m/s). ==Other websites== * [http://www.meteo.uni-bonn.de/mitarbeiter/GHeinemann/eplwg/eplwg.htm European Polar Lows Working Group] {{Webarchive|url=https://web.archive.org/web/20061002225750/http://www.meteo.uni-bonn.de/mitarbeiter/GHeinemann/eplwg/eplwg.htm |date=2006-10-02 }} * [http://nsidc.org/arcticmet/patterns/polar.low.html NSIDC] {{Webarchive|url=https://archive.today/20121209012233/http://nsidc.org/arcticmet/patterns/polar.low.html |date=2012-12-09 }} * [http://meted.ucar.edu/norlat/snow/polarlows/3.2_sat.htm Polar Low Forecasting] by MetEd ===Further reading=== Rasmussen,E.A. and Turner,J.(2003). Polar Lows: Mesoscale Weather Systems in the Polar Regions, Cambridge University Press, Cambridge, pp 612. {{Cyclones}} {{weather-stub}} [[Category:Meteorology]]