Which of the following will decrease in a rising parcel of air?

The correct answer is: D. All of the above

As a parcel of air rises, it expands and cools. This cooling causes the water vapor in the air to condense into clouds and precipitation. As a result, the relative humidity, absolute humidity, and specific humidity of the air all decrease.

• Relative humidity is the ratio of the amount of water vapor in the air to the maximum amount of water vapor that the air can hold at a given temperature. As the air cools, it can hold less water vapor, so the relative humidity increases. However, as the air rises, it cools and the relative humidity decreases.
• Absolute humidity is the actual amount of water vapor in the air, measured in grams per cubic meter. As the air rises, it expands and cools, so the absolute humidity decreases.
• Specific humidity is the ratio of the mass of water vapor to the mass of dry air in the air. As the air rises, it expands and cools, so the specific humidity decreases.

In conclusion, all of the following will decrease in a rising parcel of air: relative humidity, absolute humidity, and specific humidity.