Question #
Briefly mention the alignment of major mountain ranges of the world and explain their impact on local weather conditions, with examples.
Answer by Chad #
The major mountain ranges of the world are aligned in various directions, impacting local weather conditions differently. Here are some examples:
1. North-South Alignment: Mountain ranges aligned in a north-south direction often create a rain shadow effect. As prevailing winds hit the windward side of the mountains, they are forced upward, leading to orographic uplift. This causes the air to cool and condense, resulting in precipitation on the windward side. However, as the air moves over the mountaintop and descends on the leeward side, it heats up, reducing its ability to hold moisture and leading to a rain shadow. The result is a significant reduction in rainfall on the leeward side. For example, the Sierra Nevada mountain range in California creates a rain shadow effect, causing areas east of the range (like Nevada) to be much drier compared to the western side (like California).
2. East-West Alignment: Mountain ranges aligned in an east-west direction influence the movement of air masses. When prevailing winds encounter east-west ranges, they are forced to rise, resulting in orographic uplift. This uplift can enhance rainfall on the windward side, with moisture-laden air being pushed up, cooled, and condensed. An example is the Western Ghats in India, where the Arabian Sea's moisture-laden winds are forced to rise, leading to heavy rainfall on the windward side (western side) of the range.
3. Circumferential Alignment: In some cases, mountain ranges are aligned in a circular or semicircular fashion, affecting local weather patterns in unique ways. For instance, the Himalayas, which form a semicircular range, impact the weather in South Asia. They act as a barrier, preventing the cold air from Siberia from reaching the Indian subcontinent and providing a barrier against the summer monsoon winds. This leads to distinct seasons in South Asia, with a cold, dry winter and a wet monsoon summer.
It's important to note that these are generalized impacts, and local weather conditions can be influenced by various other factors, including proximity to the coast, latitude, and elevation.