The correct option is Eastern coasts
Explanation
The distribution of rainfall across continents is determined by global wind patterns, the shifting of pressure belts, and the influence of ocean currents. In the latitudinal belt between
35° and 4, the climate differs significantly between the western and eastern margins of continents due to the interaction of these factors.
Analysis of Rainfall Distribution (35°-40° N/S)
- Western Margins (Mediterranean Climate): In these latitudes, the western margins of continents experience a Mediterranean climate. This region is influenced by the shifting of wind belts.
- Summer: The region comes under the influence of the Subtropical High-Pressure belt, resulting in offshore trade winds and dry conditions.
- Winter: The belt shifts, bringing the region under the influence of the Westerlies, which bring rain.
- Consequently, rainfall is seasonal and moderate (typically 35-75 cm).
- Eastern Margins (Warm Temperate Eastern Margin/China Type): The eastern margins in the same latitudes receive rainfall throughout the year.
- Summer: Intense heating creates low pressure, drawing in moisture-laden onshore winds (Trade Winds or Monsoons) from the ocean, causing heavy rainfall.
- Winter: While the interiors may be dry, depressions and local storms often bring precipitation to the coast.
- Additionally, warm ocean currents along the eastern coasts increase moisture instability, enhancing precipitation.
- Conclusion: Due to the continuous supply of moisture from onshore winds in summer and cyclonic activity in winter, the eastern coasts generally receive much heavier annual rainfall (often 75-150 cm) compared to the seasonally dry western coasts.
Key Takeaway
General Rule of Rainfall Distribution:
- 10°-30° Latitudes: Rainfall is heavier on the Eastern margins (Trade Winds).
- 35°-40° Latitudes: Rainfall is heavier on the Eastern margins (Onshore winds/Monsoons vs. Dry Summer West).
- 45°-65° Latitudes: Rainfall is heavier on the Western margins (Westerlies).