The correct option is (a).
Explanation
The Sahara Desert experiences a Hot Desert Climate, characterized by extreme aridity, scorching heat during the day, and significant diurnal temperature variations due to the lack of atmospheric moisture and cloud cover.
Statement-wise Analysis:
- Statement 1 is Correct: The climate is scorching hot and parched dry. The rate of evaporation is extremely high and consistently exceeds the rate of moisture accumulation (precipitation). This moisture deficit is the primary definition of an arid environment.
- Statement 2 is Incorrect: The sky in the Sahara is typically cloudless and clear. The lack of humidity prevents the formation of heavy cloud cover, which allows for intense solar insolation during the day and rapid terrestrial radiation at night.
- Statement 3 is Incorrect: While days are extremely hot with temperatures often rising above 50°C, the nights do not remain hot. Due to the clear skies and dry air, heat escapes rapidly into space once the sun sets. Consequently, nights can be freezing cold with temperatures dropping near or below 0°C.
Key Takeaway:
Hot deserts are characterized by clear skies, evaporation rates exceeding precipitation, and extreme diurnal temperature ranges where days are intensely hot and nights are significantly cold.