1. The air temperature is 10°C and the air contains 2.87 grams of water vapor. What is the relative humidity?
Saturation mixing ratio of air parcel at 10 degrees is 7g/kg
2.87 / 7 x 100% = 41%
2. If the temperature of the air parcel in question 11 drops 10°C, how many grams of water vapor must condense out of the air?
can someone help me with this one?
To determine the grams of water vapor that must condense out of the air when the temperature drops by 10°C, you need to calculate the specific humidity at the lower temperature.
1. Calculate the saturation mixing ratio at the new temperature:
The saturation mixing ratio changes with temperature. You can find tables or equations to determine the value at the new temperature. Let's assume it is 5g/kg.
2. Calculate the change in specific humidity:
The change in specific humidity is the difference between the saturation mixing ratio at the new temperature and the original specific humidity:
Change in specific humidity = Saturation mixing ratio at new temperature - Specific humidity
3. Calculate the grams of water vapor that must condense out of the air:
To calculate the grams, you need to convert the specific humidity from g/kg to grams by multiplying it by the mass of the air parcel. The conversion factor is 0.001 (1 kilogram = 1000 grams).
Grams of water vapor to condense = Change in specific humidity (g/kg) * Mass of air parcel (kg) * 0.001
Remember to use consistent units throughout the calculations.
For example, if the original specific humidity is 2.87g and the air parcel has a mass of 1kg:
Change in specific humidity = 5g/kg - 2.87g/kg = 2.13g/kg
Grams of water vapor to condense = 2.13g/kg * 1kg * 0.001 = 0.00213 grams
To determine the grams of water vapor that must condense out of the air, you need to calculate the change in saturation mixing ratio between the initial temperature and the final temperature.
1. Calculate the initial saturation mixing ratio:
Saturation mixing ratio at 10°C = 7 g/kg
2. Calculate the final saturation mixing ratio:
Saturation mixing ratio at -10°C = 1.2 g/kg
3. Calculate the difference in saturation mixing ratio:
Change in saturation mixing ratio = Initial saturation mixing ratio - Final saturation mixing ratio
= 7 g/kg - 1.2 g/kg
= 5.8 g/kg
4. Convert the change in saturation mixing ratio to grams of water vapor:
Change in saturation mixing ratio = 5.8 g/kg
If the air parcel contains 2.87 grams initially, then:
grams of water vapor to condense = Change in saturation mixing ratio * initial mass of air
= 5.8 g/kg * (2.87 kg/1000 g)
≈ 0.0167 grams
Therefore, approximately 0.0167 grams of water vapor must condense out of the air when the temperature drops by 10°C.