The correct option is 1 and 3 only.
Explanation
The question pertains to the Dry Climates (Group B) in the Köppen classification, specifically the Subtropical Steppe (BSh) and Subtropical Desert (BWh). These climates are characterized by evaporation exceeding precipitation. The Subtropical Steppe is a semi-arid climate, while the Subtropical Desert is an arid climate.
Statement-wise Analysis
- Statement 1 is Correct. The Subtropical Steppe (BSh) acts as a transition zone between the humid climates (such as Tropical Savanna or Humid Subtropical) and the arid Subtropical Desert (BWh). Geographically, these semi-arid regions surround the core desert areas, marking the gradation from moisture-sufficient regions to water-deficient deserts.
- Statement 2 is Incorrect. Fog is a characteristic feature, not absent, in coastal deserts bordering cold currents. In regions like the Atacama Desert (bordered by the cold Peru/Humboldt Current) and the Namib Desert (bordered by the cold Benguela Current), the chilling of air by the cold water produces advection fog and low stratus clouds. However, this stable air does not produce precipitation, reinforcing aridity while maintaining high humidity and fog.
- Statement 3 is Correct. These climates are characterized by clear skies and low humidity. This allows for intense solar heating during the day and rapid loss of heat through terrestrial radiation at night, resulting in a high diurnal range of temperature. Similarly, the annual range of temperature is relatively high compared to equatorial climates due to the variation in solar insolation between summer and winter.
Key Takeaway: Coastal deserts along the western margins of continents in the subtropics are often associated with cold ocean currents, which cause desiccation (aridity) but frequently produce fog and low clouds.