Absolute HumidityAbsolute Humidity

Parcel Size 2M cubed/Water Content 10g/Absolute Humidity 5g/m cubed.

Parcel Size 1M cubed/Water Content 10g/Absolute Humidity 10g/m cubed.

Absolute Humidity FormulaAbsolute Humidity Formula

Absolute Humidity= mass of water vapor/volume of airAbsolute Humidity= mass of water vapor/volume of air

Specific Humidity FormulaSpecific Humidity Formula

Specific Humidity= mass of water vapor/total mass of airSpecific Humidity= mass of water vapor/total mass of air

Mixing RatioMixing Ratio

Mixing Ratio= mass of water vapor/mass of dry airMixing Ratio= mass of water vapor/mass of dry air

Water VaporWater Vapor

32F can hold about 2g/cubic meter32F can hold about 2g/cubic meter

50F can hold about 9g/ cubic meter50F can hold about 9g/ cubic meter

75F can hold about 23g/ cubic meter75F can hold about 23g/ cubic meter

Average Specific Humidity by latitudeAverage Specific Humidity by latitude

60N 5g/kg60N 5g/kg

30N 11g/kg30N 11g/kg

Equator 18g/kgEquator 18g/kg

Saturation Vapor PressureSaturation Vapor Pressure14F =2mb(vapor pressure14F =2mb(vapor pressure32F=5mb(vapor pressure32F=5mb(vapor pressure50F=12mb(vapor pressure50F=12mb(vapor pressure

Relative HumidityRelative Humidity

RH=Actual vapor pressure/saturation vapor pressure X 100%RH=Actual vapor pressure/saturation vapor pressure X 100%

TEMPSTEMPS

10C Potential 9G10C Potential 9G 20C Potential 17G20C Potential 17G10C Actual 9G10C Actual 9G 20C Actual 9G20C Actual 9GRH= 9/9=100%RH= 9/9=100% RH= 9/17=53%RH= 9/17=53%

Relative Humidity by Day(EXAMPLE)Relative Humidity by Day(EXAMPLE)6:00 AM6:00 AM 12PM12PM 6PM6PM MIDNIGHTMIDNIGHTT 25FT 25F T30FT30F 33F33F 28F28FRH 77%RH 77% RH50%RH50% RH20%RH20% RH 67%RH 67%