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Inches Hg to Millibars to Altitude conversion   (standard pressure) | ||||||||||||||||
29.92" | = | 1013 mb | = | 0000' | 23.98" | = | 0812 mb | = | 6000' | 14.76" | = | 0500 mb | = | FL 180 | ||
28.85" | = | 0977 mb | = | 1000' | 23.09" | = | 0782 mb | = | 7000' | 11.81" | = | 0400 mb | = | FL 240 | ||
27.82" | = | 0942 mb | = | 2000' | 22.24" | = | 0753 mb | = | 8000' | 8.86" | = | 0300 mb | = | FL 300 | ||
26.81" | = | 0908 mb | = | 3000' | 21.38" | = | 0724 mb | = | 9000' | 6.64" | = | 0225 mb | = | FL 360 | ||
25.84" | = | 0875 mb | = | 4000' | 20.58" | = | 0697 mb | = | 10,000' | 5.17" | = | 0175 mb | = | FL 420 | ||
24.89" | = | 0843 mb | = | 5000' | 19.19" | = | 0650 mb | = | 12,000' | 3.69" | = | 0125 mb | = | FL 480 |
From NASA:
New technology for detecting turbulence
In aviation, the Richardson number is used as a rough measure of expected air turbulence. A lower value indicates a higher degree of turbulence.
Values in the range 10 to 0.1 are typical, with values below unity indicating significant turbulence.
- from
https://en.wikipedia.org/wiki/Richardson_number
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