how do i find the dew point temperature if the specific humidity is 3.5g/kg?
change the specific humidity to relative humidity. That in itself is a task, see equation (3) in https://www.vaisala.com/sites/default/files/documents/Humidity_Conversion_Formulas_B210973EN-F.pdf.
Then, you can use charts (or the ln formula) to find dewpoint. Your text probably has those.
To find the dew point temperature given the specific humidity, you need to use a formula or a dew point calculator.
One commonly used formula to calculate the dew point temperature is the Magnus formula, also known as the Arden Buck equation. The formula is as follows:
Td = (243.5 * (log(SRH/100) + ((17.67 * T) / (243.5 + T)))) / (17.67 - (log(SRH/100) + ((17.67 * T) / (243.5 + T)))))
Where:
- Td represents the dew point temperature in degrees Celsius
- SRH represents the specific humidity in g/kg
- T represents the actual air temperature in degrees Celsius
To use this formula, you need to know the air temperature. Let's assume the air temperature is 25 degrees Celsius.
Now, plug in the given values into the formula:
Td = (243.5 * (log(3.5/100) + ((17.67 * 25) / (243.5 + 25)))) / (17.67 - (log(3.5/100) + ((17.67 * 25) / (243.5 + 25)))))
You can calculate this equation using a scientific calculator or a programming language that supports logarithmic functions.
Alternatively, you can use an online dew point calculator where you input the specific humidity and it will give you the dew point temperature. There are several such calculators available on the internet.
Remember that the dew point temperature represents the temperature at which air becomes saturated and condensation occurs.