What are the processes by which moisture is added to unsaturated air?

Moisture is added to unsaturated air primarily through processes such as evaporation and sublimation.

Evaporation occurs when liquid water transforms into water vapor, increasing the amount of moisture in the air. This process can happen in various environments, such as lakes, rivers, or even the surface of wet soil. As the water heats up, molecules gain energy and transition into a gaseous state, thereby contributing to the humidity in the surrounding air.

Sublimation, on the other hand, is the process where ice or snow directly transitions into water vapor without first becoming liquid. This phenomenon is particularly noticeable in cold environments, where ice may dissipate into the atmosphere directly, enriching the air with moisture.

Both of these processes play significant roles in the hydrological cycle and influence weather patterns, humidity levels, and atmospheric conditions. Understanding how moisture is added to unsaturated air is crucial for pilots, as these factors can affect flight operations, visibility, and weather phenomena.