போஃபார்ட்டு காற்றுவீச்சு அளவீடு
[[File:Beaufort scale 12 notext.jpg|right|300px|thumb|Force 12 at sea]]
 '''போஃபோர்ட்டு காற்றுவீச்சு அளவீடு''' (''Beaufort scale'') என்பது காற்றுவீச்சின் வலிமையை வகைப்படுத்திக்கூறும் ஓர் அளவீடு.
 
 == வரலாறு ==
 இவ்வளவீட்டு முறையை ஐயர்லாந்தில் பிறந்த பிரான்சிசு போஃபோர்ட்டு 1805 இல் கண்டுபிடித்தார். இவர் ''ரியர் அட்மிரல்'' என்னும் வேந்திய கடற்படைத்துறையின் உயர் பதவியில் இருந்தார். இவ்வளவீட்டு முறையை '&quot;எச்சு.எம்.எசு வுல்விச்சு&quot; என்னும் கப்பலில் இருந்தபொழுது உருவாக்கினார். இவ்வளவீட்டு முறை இதற்குமுன் தானியே திஃபோ போன்ற பலரும் உருவாக்கிய முறைகளையும் உள்வாங்கி உருவாக்கப்பட்டது. இந்த அளவீட்டு முறை முதன்முதலாக &quot;எச்சு.எம்.எசு பீகல்&quot; என்னும் கப்பல் கடலில் சென்றபொழுது பயன்படுத்தப்பட்டது. பின்னர் இம்முறையைப் பிரித்தானியா வானியல் நிலையம் எடுத்தாண்டது.&lt;ref name=&quot;met office&quot;&gt;{{cite web|url=http://www.metoffice.gov.uk/media/pdf/4/4/Fact_Sheet_No._6_-_Beaufort_Scale.pdf|publisher=Met Office|title=National Meteorological Library and Archive Fact sheet 6 — The Beaufort Scale|accessdate=2011-05-13|archive-date=2012-10-02|archive-url=https://web.archive.org/web/20121002134429/http://www.metoffice.gov.uk/media/pdf/4/4/Fact_Sheet_No._6_-_Beaufort_Scale.pdf|url-status=dead}}&lt;/ref&gt;
 
 1946 போஃபோர்ட்டு அளவீட்டின்படி&lt;ref&gt;{{cite book | title = Environmental Oceanography | author = Tom Beer | publisher = CRC Press | year = 1997 | isbn = 0-8493-8425-7 | url = https://books.google.com/books?id=pgZtaB-qOmYC&amp;pg=PA224&amp;dq=%22Beaufort+Scale%22+0.836}}&lt;/ref&gt; காற்றுவீச்சின் விரைவு ''v'':
 
 : ''v'' = 0.836 ''B''&lt;sup&gt;3/2&lt;/sup&gt; மீ/நொடி
 
 இதில் ''v''  என்பது கடல்மட்டத்தில் இருந்து 10 மீட்டர் உயரத்தில் வீசும் காற்றின் விரைவு. ''B'' என்பது போஃபோர்ட்டு அளவீட்டு எண். எடுத்துக்காட்டாக ''B'' = 9.5 என்பது  24.5&amp;nbsp;மீ/நொடி என்பதற்கு ஈடானது. இது போஃபோர்ட்டு அளவீட்டின் 10 என்பதன் குறைந்த எல்லை. இந்த வாய்பாட்டின்படி அரிக்கேன் புயலின் உச்ச எண் 23 ஆகும்.
 
 == நவீன அளவீடு ==
 {{Translate}}
 &lt;!-- Please add description row to explain meaning of columns --&gt;
 {| class=&quot;wikitable&quot; border=1
 &lt;!--
 ! rowspan=&quot;2&quot; | Beaufort number !! rowspan=&quot;2&quot; | Description !! colspan=&quot;4&quot; | Wind speed !! colspan=&quot;2&quot; | Wave height !! rowspan=&quot;2&quot; width=&quot;100&quot; | Sea conditions !!rowspan=&quot;2&quot; width=&quot;100&quot;|Land conditions!!rowspan=&quot;2&quot;|Sea state photo
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 !width=&quot;50&quot;|km/h!!width=&quot;50&quot;|mph!!width=&quot;50&quot;|[[Knot (unit)|kn]]!!width=&quot;50&quot;|[[metre per second|m/s]]!!width=&quot;50&quot;|[[மீட்டர்|m]] !!width=&quot;50&quot;|[[அடி (அளவை)|ft]]
 |-
 --&gt;
 ! போஃபோர்ட்டு எண்&lt;br /&gt;Beaufort number !! விளக்கம் !! காற்றுவீச்சின் விரைவு !! அலை உயரம் !! width=&quot;130&quot; | கடலின் நிலை !! width=&quot;120&quot;|நிலத்தின் நிலை !! கடல்நிலை ஒளிப்படம் !! எச்சரிக்கைக் கொடி
 |-
 ! style=&quot;background-color: #FFFFFF; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_9&quot; | 0
 |rowspan=4| அமைதி || &lt; 1&amp;nbsp;km/h ||rowspan=2| 0 [[மீட்டர்|m]] ||rowspan=4| கடல் பளிங்குபோல ||rowspan=4| அமைதி. புகை நேர் செங்குத்தாக எழும். ||rowspan=4| [[File:beaufort scale 0.jpg|120px]] ||rowspan=4|
 |-
 | &lt; 1&amp;nbsp;மணிக்கு மைல்கள்
 |-
 | &lt; 1 [[Knot (unit)|knot]] ||rowspan=2| 0 [[அடி (அளவை)|அடி]]
 |-
 | &lt; 0.3 மீ/நொடி
 |-
 ! style=&quot;background-color: #CCFFFF; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_1&quot; | 1
 |rowspan=4| Light air || 1–5&amp;nbsp;km/h ||rowspan=2| 0–0.2 m ||rowspan=4| Ripples with the appearance of scales are formed, but without foam crests ||rowspan=4| Smoke drift indicates wind direction. Leaves and wind vanes are stationary. ||rowspan=4| [[File:beaufort scale 1.jpg|120px]] ||rowspan=4|
 |-
 | 1–3&amp;nbsp;மணிக்கு மைல்கள்
 |-
 | 1–3 முடிச்சுகள் (knots) ||rowspan=2| 0–1&amp;nbsp;
 |-
 | 0.3–1.5&amp;nbsp;மீ/நொடி
 |-
 ! style=&quot;background-color: #99FFCC; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_2&quot; | 2
 |rowspan=4| மெல்லிய காற்று || 6–11&amp;nbsp;கிமீ/மணி ||rowspan=2| 0.2–0.5 m ||rowspan=4| சிறு அலைத்துளிகள், still short but more pronounced; crests have a glassy appearance and do not break ||rowspan=4| Wind felt on exposed skin. Leaves rustle. Wind vanes begin to move. ||rowspan=4| [[File:beaufort scale 2.jpg|120px]] ||rowspan=4|
 |-
 | 4–7&amp;nbsp;மணிக்கு மைல்கள்
 |-
 | 4–6 முடிச்சுகள் ||rowspan=2| 1–2&amp;nbsp;அடி
 |-
 | 1.6–3.3&amp;nbsp;மீ/நொடி
 |-
 ! style=&quot;background-color: #99FF99; font-size: large;&quot;  rowspan=4 id=&quot;Beaufort_Number_3&quot; | 3
 |rowspan=4| Gentle breeze || 12–19&amp;nbsp;km/h ||rowspan=2| 0.5–1 m ||rowspan=4| Large wavelets. Crests begin to break; scattered [[கடலலை|whitecaps]] ||rowspan=4| Leaves and small twigs constantly moving, light flags extended. ||rowspan=4| [[File:beaufort scale 3.jpg|120px]] ||rowspan=4|
 |-
 | 8–12&amp;nbsp;mph
 |-
 | 7–10 knots ||rowspan=2| 2–3.5&amp;nbsp;அடி
 |-
 | 3.4–5.5&amp;nbsp;மீ/நொடி
 |-
 ! style=&quot;background-color: #99FF66; font-size: large;&quot;  rowspan=4 id=&quot;Beaufort_Number_4&quot; | 4
 |rowspan=4| Moderate breeze || 20–28&amp;nbsp;km/h ||rowspan=2| 1–2 m ||rowspan=4| Small waves with breaking crests. Fairly frequent whitecaps. ||rowspan=4| Dust and loose paper raised. Small branches begin to move. ||rowspan=4| [[File:beaufort scale 4.jpg|120px]] ||rowspan=4|
 |-
 | 13–18&amp;nbsp;mph
 |-
 | 11–16 knots ||rowspan=2| 3.5–6&amp;nbsp;ft
 |-
 | 5.5–7.9&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #99FF00; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_5&quot; | 5
 |rowspan=4| Fresh breeze || 29–38&amp;nbsp;km/h ||rowspan=2| 2–3 m ||rowspan=4| Moderate waves of some length. Many whitecaps. Small amounts of spray. ||rowspan=4| Branches of a moderate size move. Small trees in leaf begin to sway. ||rowspan=4| [[File:beaufort scale 5.jpg|120px]] ||rowspan=4|
 |-
 | 19–24&amp;nbsp;mph
 |-
 | 17–21 knots ||rowspan=2| 6–9&amp;nbsp;ft
 |-
 | 8–10.7&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #CCFF00; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_6&quot; | 6
 |rowspan=4| Strong breeze || 39–49&amp;nbsp;km/h ||rowspan=2| 3–4 m||rowspan=4| Long waves begin to form. White foam crests are very frequent. Some airborne spray is present. ||rowspan=4| Large branches in motion. Whistling heard in overhead wires. Umbrella use becomes difficult. Empty plastic bins tip over. ||rowspan=4| [[File:beaufort scale 6.jpg|120px]] ||rowspan=4| [[File:Gale pennant.svg|100px]]
 |-
 | 25–31&amp;nbsp;mph
 |-
 | 22–27 knots ||rowspan=2| 9–13&amp;nbsp;ft
 |-
 | 10.8–13.8&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #FFFF00; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_7&quot; | 7
 |rowspan=4| High wind,&lt;br/&gt;moderate gale,&lt;br/&gt;near gale || 50–61&amp;nbsp;km/h||rowspan=2| 4–5.5 m ||rowspan=4| Sea heaps up. Some foam from breaking waves is blown into streaks along wind direction. Moderate amounts of airborne spray. ||rowspan=4| Whole trees in motion. Effort needed to walk against the wind.||rowspan=4| [[File:beaufort scale 7.jpg|120px]] ||rowspan=4| [[File:Gale pennant.svg|100px]]
 |-
 | 32–38&amp;nbsp;mph
 |-
 | 28–33 knots ||rowspan=2| 13–19&amp;nbsp;ft
 |-
 | 13.9–17.1&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #FFCC00; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_8&quot; | 8
 |rowspan=4| [[Gale]],&lt;br/&gt;fresh gale || 62–74&amp;nbsp;km/h ||rowspan=2| 5.5–7.5 m ||rowspan=4| Moderately high waves with breaking crests forming spindrift. Well-marked streaks of foam are blown along wind direction. Considerable airborne spray. ||rowspan=4| Some twigs broken from trees. Cars veer on road. Progress on foot is seriously impeded. ||rowspan=4| [[File:beaufort scale 8.jpg|120px]] ||rowspan=4| [[File:Gale pennant.svg|100px]]&lt;br&gt;[[File:Gale pennant.svg|100px]]
 |-
 | 39–46&amp;nbsp;mph
 |-
 | 34–40 knots ||rowspan=2| 18–25&amp;nbsp;ft
 |-
 | 17.2–20.7&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #FF9900; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_9&quot; | 9
 |rowspan=4| Strong/severe gale || 75–88&amp;nbsp;km/h ||rowspan=2| 7–10 m ||rowspan=4| High waves whose crests sometimes roll over. Dense foam is blown along wind direction. Large amounts of airborne spray may begin to reduce visibility. ||rowspan=4| Some branches break off trees, and some small trees blow over. Construction/temporary signs and barricades blow over. ||rowspan=4| [[File:beaufort scale 9.jpg|120px]] ||rowspan=4| [[File:Gale pennant.svg|100px]]&lt;br&gt;[[File:Gale pennant.svg|100px]]
 |-
 | 47–54&amp;nbsp;mph
 |-
 | 41–47 knots ||rowspan=2| 23–32&amp;nbsp;ft
 |-
 | 20.8–24.4&amp;nbsp;m/s
 |-
 |+ {{anchor|Storm-force}}
 ! style=&quot;background-color: #FF6600; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_10&quot; | 10
 |rowspan=4| [[Storm]],&lt;ref name=&quot;forcenamenote&quot;&gt;The names &quot;storm&quot; and &quot;hurricane&quot; on the Beaufort scale refer only to wind strength, and do not necessarily mean that other severe weather (for instance, a [[இடியுடன் கூடிய மழை]] or [[வெப்ப மண்டலச் சூறாவளி]]) is present. To avoid confusion, strong wind warnings will often speak of e.g. &quot;hurricane-force winds&quot;.&lt;/ref&gt;&lt;br/&gt;whole gale || 89–102&amp;nbsp;km/h ||rowspan=2| 9–12.5 m ||rowspan=4| Very high waves with overhanging crests. Large patches of foam from wave crests give the sea a white appearance. Considerable tumbling of waves with heavy impact. Large amounts of airborne spray reduce visibility. ||rowspan=4| Trees are broken off or uprooted, structural damage likely. ||rowspan=4| [[File:beaufort scale 10.jpg|120px]] ||rowspan=4| [[File:Storm warning.svg|100px]]
 |-
 | 55–63&amp;nbsp;mph
 |-
 | 48–55 knots ||rowspan=2| 29–41&amp;nbsp;ft
 |-
 | 24.5–28.4&amp;nbsp;m/s
 |-
 ! style=&quot;background-color: #FF3300; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_11&quot; | 11
 |rowspan=4| Violent storm || 103–117&amp;nbsp;km/h ||rowspan=2| 11.5–16 m ||rowspan=4| Exceptionally high waves. Very large patches of foam, driven before the wind, cover much of the sea surface. Very large amounts of airborne spray severely reduce visibility. ||rowspan=4| Widespread vegetation and structural damage likely.||rowspan=4| [[File:beaufort scale 11.jpg|120px]] ||rowspan=4| [[File:Storm warning.svg|100px]]
 |-
 | 64–72&amp;nbsp;mph
 |-
 | 56–63 knots ||rowspan=2| 37–52&amp;nbsp;ft
 |-
 | 28.5–32.6&amp;nbsp;m/s
 |-
 |+ {{anchor|Hurricane force}}
 ! style=&quot;background-color: #FF0000; font-size: large;&quot; rowspan=4 id=&quot;Beaufort_Number_12&quot; | 12
 |rowspan=4| [[வெப்ப மண்டலச் சூறாவளி]] force &lt;ref name=&quot;forcenamenote&quot;/&gt; || ≥ 118&amp;nbsp;km/h ||rowspan=2| ≥ 14 m ||rowspan=4| Huge waves. Sea is completely white with foam and spray. Air is filled with driving spray, greatly reducing visibility. ||rowspan=4| Severe widespread damage to vegetation and structures. Debris and unsecured objects are hurled about. ||rowspan=4| [[File:beaufort scale 12.jpg|120px]] ||rowspan=4| [[File:Storm warning.svg|100px]]&lt;br&gt;&lt;br&gt;[[File:Storm warning.svg|100px]]
 |-
 | ≥ 73&amp;nbsp;mph
 |-
 | ≥ 64 knots ||rowspan=2| ≥ 46&amp;nbsp;ft
 |-
 | ≥ 32.7&amp;nbsp;m/s
 |-
 ! colspan=&quot;8&quot; | References: Met Office,&lt;ref&gt;{{cite web| title = Beaufort wind force scale| url = http://www.metoffice.gov.uk/guide/weather/marine/beaufort-scale| publisher = Met Office| accessdate = November 27, 2015}}&lt;/ref&gt; Royal Meteorological Society,&lt;ref&gt;{{cite web| title = Beaufort Scale| url = http://www.rmets.org/weather-and-climate/observing/beaufort-scale| publisher = Royal Meteorological Society| accessdate = November 27, 2015}}&lt;/ref&gt; ''Encyclopædia Britannica''&lt;ref&gt;{{cite web| title = Beaufort Scale| url = http://www.britannica.com/science/Beaufort-scale| work = Encyclopædia Britannica| accessdate = November 27, 2015}}&lt;/ref&gt;
 |}
 
 ==அடிக்குறிப்புகளும் மேற்கோள்களும்==
 {{Reflist}}
 
 == வெளி இணைப்புகள் ==
 {{Commons category|Beaufort Scale|போஃபார்ட்டு அளவீடு}}
 * [https://www.youtube.com/watch?v=-tdSVqOybqs Film of Wind Scale]
 * [http://www.knmi.nl/~koek/Publicaties/Hisklim13.pdf Historical Wind Speed Equivalents Of The Beaufort Scale] {{Webarchive|url=https://web.archive.org/web/20120710140044/http://www.knmi.nl/~koek/Publicaties/Hisklim13.pdf |date=2012-07-10 }}
 * [http://www.howtoons.com/wp-content/uploads/2009/05/beaufortscale.png Howtoons Poster] {{Webarchive|url=https://web.archive.org/web/20110712224622/http://www.howtoons.com/wp-content/uploads/2009/05/beaufortscale.png |date=2011-07-12 }} showing effects on land/sea effects at each step.
 {{Authority control}}
 
 [[பகுப்பு:காற்று]]