Temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air, considered at the same pressure.
The temperature a sample of dry air at pressure would have in order that its density equal that of the sample of moist air at temperature , pressure , and water vapor mixing ratio . It is given by a If there is also liquid water in the air this is modified as where is the liquid water mixing ratio (in grams of liquid water per gram of dry air). The virtual temperature is thus defined because it allows the ideal gas law to be used for situations in which the air is not dry, i.e. moist air of temperature behaves identically to dry air of temperature .
The temperature at which dry air would have the same density as moist air. The introduction of moisture makes the air less dense. The difference between virtual and actual temperature is very small in cold air which cannot hold much moisture, but in tropical air the virtual temperature may be several degrees higher than the actual temperature.
The virtual temperature is the temperature of dry air that would have the same density and pressure as the moist air.
Virtual temperature is a fictitious temperature that takes into account moisture in the air. The formal definition of virtual temperature is the temperature that dry air would have if its pressure and specific volume were equal to those of a given sample of moist air. Virtual temperature allows meteorologists to use the equation of state for dry air even though moisture is present.
The temperature a parcel of air would have if the moisture in it were removed and its specific heat was added to the parcel.
The virtual temperature is the temperature a parcel which contains no moisture would have to equal the density of a parcel at a specific temperature and humidity.
The temperature that a volume of dry air must have in order to have the same density as an equal volume of moist air at the same pressure. (Since moist air is always less dense than dry air, the virtual temperature is always greater than the moist air temperature.)
(Also called density temperature.) The virtual temperature = / Îµ)/(1 + ), where is the mixing ratio and Îµ is the ratio of the gas constants of air and water vapor, â‰ˆ 0.622. The virtual temperature allows the use of the dry-air equation of state for moist air, except with replaced by . Hence the virtual temperature is the temperature that dry dry air would have if its pressure and density were equal to those of a given sample of moist air. For typical observed values of , the virtual temperature may be approximated by = (1 + 0.61 ) . Some authors incorporate the density increment due to liquid or solid water into virtual temperature, in which case the definition becomes = /Îµ)/(1 + + ) â‰ˆ (1 + 0.61 âˆ’ ), where is the liquid or liquid plus solid water mixing ratio.