Consider the following statements: 1. The difference between the moisture-holding capacity of air and its actual humidity is called saturation deficit. 2. The temperature to which air has to be cooled in order to reach saturation is called dew point. Which of the statements given above is/are correct?

Statement 1 is correct as saturation deficit, also known as vapor pressure deficit (VPD), is defined as the difference between the actual amount of moisture in the air and the maximum amount of moisture the air can hold at saturation for a given temperature [t2][t6]. It indicates the additional water vapor that can be added before saturation occurs [t4]. Statement 2 is also correct; the dew point is the specific temperature to which a given parcel of air must be cooled (at constant pressure) to reach 100% relative humidity or saturation [c1][t3]. At this temperature, the air's moisture-holding capacity is met, and any further cooling leads to condensation into liquid water, such as dew, fog, or clouds [c4][t5][t7]. Since both statements accurately define these meteorological concepts, option 3 is the correct choice.

Sources

1. [1] https://en.wikipedia.org/wiki/Vapour-pressure_deficit
2. [2] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 10: Water in the Atmosphere > CHAPTER > p. 86
3. [3] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 13: Weather > Notes > p. 120