The water vapour mixing ratio of an air parcel increases from 10 g kg\(^{-1}\) to 20 g kg\(^{-1}\) at a constant pressure of 1010 hPa and temperature of 300 K. The change in virtual temperature is \(\underline{\hspace{2cm}}\) K (to one decimal place).
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Correct Answer: 1.7
Solution and Explanation
- \( R_d \) is the gas constant for dry air,
- \( R_w \) is the gas constant for water vapour,
- \( \Delta w \) is the change in the water vapour mixing ratio.
Substitute the given values and solve for the change in virtual temperature: \[ \Delta T_v \approx 1.7 \, \text{K}. \] Thus, the change in virtual temperature is \( 1.7 \, \text{K} \).
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