Final answer:
The pattern of precipitation is influenced by air mass movement, geographic features like mountains (orographic effect), temperature, proximity to oceans, and global wind patterns, leading to varying precipitation and fresh water resource distribution globally.
Step-by-step explanation:
The global pattern of precipitation is primarily determined by the movement of air masses and their interaction with geographic features. One key aspect of this pattern is the orographic effect, which occurs when moist air is forced to rise over a mountain range, cooling and condensing to release precipitation on the windward side. The descending air on the leeward side warms up, reducing its humidity and creating arid conditions, known as a rain shadow effect.
Around 30° N and 30° S latitude, there is a belt of dry air masses leading to low precipitation levels and the presence of the world's largest deserts. Temperature also influences precipitation, with warm air having the capacity to hold more moisture, resulting in higher rainfall in tropical areas. Proximity to oceans and the presence of mountain ranges can amplify or reduce precipitation amounts in various regions.
Precipitation patterns are crucial in determining the availability of fresh water resources. These unevenly distributed rainfall patterns are linked to global wind circulation cells. For instance, the intense equatorial sunlight heats the air, causing it to rise and lose moisture through precipitation, while descending air around 30° latitudes leads to drier conditions.