Editing Pascal (unit) (section)

=== Hectopascal and millibar units ===
{{main|Bar (unit)}}
The units of atmospheric pressure commonly used in [[meteorology]] were formerly the [[Bar (unit)|bar]] ({{val|100,000|u=Pa}}), which is close to the average air pressure on Earth, and the millibar. Since the introduction of [[International System of Units|SI units]], meteorologists generally measure atmospheric pressure in hectopascals (hPa), equal to 100 pascals or 1 millibar.<ref>{{cite web|url=http://www.knmi.nl/actueel/|title=KNMI – Weer – Waarnemingen|access-date=4 December 2016}}</ref><ref>{{cite web|url=http://www.meteo.be/meteo/view/fr/68771-FAQ%20sur%20le%20temps.html?view=195695|title=Comment convertir la pression? – IRM|access-date=4 December 2016}}</ref><ref>{{Cite web|url=http://www.dwd.de/de/WundK/W_aktuell/Beobachtungen.htm|title=DWD|access-date=20 December 2006|archive-url=https://web.archive.org/web/20080210040845/http://www.dwd.de/de/WundK/W_aktuell/Beobachtungen.htm|archive-date=10 February 2008|url-status=dead}}</ref><ref>{{cite web|url=http://www.jma.go.jp/en/g3/index.html|title=Japan Meteorological Agency – Weather Maps|access-date=4 December 2016}}</ref><ref>{{Cite web|url=http://www.meteoam.it/modules.php?name=analisiPrevisioniSuolo|archive-url=https://web.archive.org/web/20060506192242/http://www.meteoam.it/modules.php?name=analisiPrevisioniSuolo|url-status=dead|title=MDD|archive-date=6 May 2006}}</ref><ref>[http://weather.noaa.gov/weather/current/KDCA.html NOAA]</ref><ref>{{cite web|url=http://www.metoffice.gov.uk/guide/weather/symbols#units|title=Key to symbols and terms|first=Met Office|last=United Kingdom|access-date=4 December 2016}}</ref> Exceptions include Canada, which uses kilopascals (kPa). In many other fields of science, prefixes that are a power of 1000 are preferred, which theoretically excludes hectopascal from use.<ref>{{Cite web|url=http://www.ctv.ca/servlet/HTMLTemplate/!ctvDynNews/Weather/Weather?City=Montreal|archive-url=https://web.archive.org/web/20110604131321/http://www.ctv.ca/servlet/HTMLTemplate/!ctvDynNews/Weather/Weather?City=Montreal|url-status=dead|title=CTV News, weather; current conditions in Montreal|archive-date=4 June 2011}}</ref><ref>{{cite web|url=http://www.weatheroffice.gc.ca/city/pages/qc-147_metric_e.html|title=Montréal, QC – 7 Day Forecast – Environment Canada|first=Environment|last=Canada|access-date=4 December 2016|archive-date=30 November 2017|archive-url=https://web.archive.org/web/20171130163853/http://www.weatheroffice.gc.ca/city/pages/qc-147_metric_e.html|url-status=dead}}</ref>

Many countries still use millibars to measure atmospheric pressure. In practically all other fields, the kilopascal is used instead.<ref>Ambler Thompson (Editor) {{google books|pTw-SCI7EkoC|Guide for the Use of the International System of Units (SI) (rev. ): The ...|page=66}}</ref>