Pe un forum am primit întrebarea lui Dounia Philippe:
“How can we calculate the Relative Humidity with Temperature and Dewpoint only.”
Am răspuns :
Dear Dounia,
You can try this address, where you enter the air temperature and the dew point, and get the relative humidity:
http://www.hpc.ncep.noaa.gov/html/dewrh.shtml
The relative humidity is a ratio between two values of water vapour pressure in the air. When you know only the air temperature, you can find out from tables or from Magnus formula, the saturation water vapour pressure in the air. That’s the denominator. The dew point has associated from the same tables or equation the actual water vapour pressure in the air. That’s the numerator. If you multiply with 100, you get the relative humidity in percents. During the rain, both values of vapour pressure are equal, so the relative humidity is 100%.
Best regards,
Titus Filipas,
University of Craiova,
Romania
Etichete air temperature, dew point, Magnus equation, Punct de rouă, Relative Humidity, saturation, Titus Filipas, Umiditate relativă, vapour pressure
